Home Physical Sciences Development and validation of a stability indicating UPLC-DAD method coupled with MS-TQD for ramipril and thymoquinone in bioactive SNEDDS with in silico toxicity analysis of ramipril degradation products
Article Open Access

Development and validation of a stability indicating UPLC-DAD method coupled with MS-TQD for ramipril and thymoquinone in bioactive SNEDDS with in silico toxicity analysis of ramipril degradation products

  • Ehab M. Elzayat , Abdelrahman Y. Sherif EMAIL logo , Ahmad Abdul-Wahhab Shahba , Mohsin Kazi , Mohammed Alyahya and Hany W. Darwish
Published/Copyright: August 2, 2024

Abstract

The identification of degradation products of therapeutic molecules in pharmaceutical formulations has gained significant attention due to their potential impact on patient safety. Ramipril (RP), an antihypertensive agent, was incorporated into a self-nanoemulsifying drug delivery system (SNEDDS), which greatly enhanced its bioavailability. However, none of the previous studies have investigated the toxicological effects of these degradation products that may form during storage. Moreover, a bioactive SNEDDS containing black cumin oil (BCO) and its bioactive ingredient, thymoquinone (TQ), was used to further enhance the therapeutic activity of RP. To assess the stability of the proposed formulation, a validated ultrahigh-performance liquid chromatography (UPLC) method was developed to simultaneously measure the concentrations of RP and TQ. The formulation was subjected to accelerated stress conditions to facilitate drug degradation. The resulting degradation products were analyzed using mass spectroscopy (MS) to determine their molecular mass, and their chemical structures were in silico predicted using Zeneth Nexus software, while their toxicity was assessed using in silico Derek Nexus software. RP and TQ, along with their degradation products, were separated using an HSS T3 column at a flow rate of 0.25 mL/min. The detection wavelengths for RP and TQ were 210 and 254 nm, respectively. The developed UPLC method exhibited acceptable linearity for both RP and TQ, with correlation coefficient (r 2) values exceeding 0.9995 and 0.9998, respectively. The method provided accurate, precise, and high-resolution analysis of both drugs and their degradation products within a short run time of less than 3.2 min. The toxicity and mutagenicity of two alkaline degradation products of RP were predicted using in silico software Derek Nexus (version 6.3). Several toxicity endpoints, including chromosomal damage, skin sensitization, and hepatotoxicity, were predicted. Overall, the developed method can be used to evaluate the stability and integrity of RP and TQ during the development of the proposed antihypertensive formulation.

Graphical abstract

1 Introduction

The low solubility of therapeutic drug molecules poses a challenge to their bioavailability [1]. Extensive research has been conducted to develop drug delivery systems that can significantly enhance the solubility [2,3]. However, some drug molecules face stability issues due to incompatibility with excipients in the formulation [4,5]. Therefore, it is essential to identify and examine the toxicological degradation products formed within these drug delivery systems to assess their impact on patient safety [6].

Ramipril (RP, Figure 1a) is a commonly used antihypertensive agent for hypertension treatment [7]. It exerts its pharmacological effects by inhibiting angiotensin-converting enzyme (ACE) [8]. Additionally, RP has shown protective effects on mortality following a heart attack [9]. However, its limited solubility leads to poor dissolution and reduced bioavailability [10]. To address this issue, various drug delivery systems have been employed, including the self-nanoemulsifying drug delivery system (SNEDDS), which has been extensively used to improve the dissolution rate and bioavailability of RP [1015]. More recently, a bioactive SNEDDS formulation has been developed to enhance the therapeutic activity of loaded drug molecules and improve the bioavailability. This is achieved through the incorporation of oil-containing phytochemicals with nutraceutical properties [16,17].

Figure 1 
               Chemical structures of (a) RP and (b) TQ.
Figure 1

Chemical structures of (a) RP and (b) TQ.

Nigella sativa has a long history of use in various cultures for treating different diseases, including hypertension [18,19]. Recent clinical studies have demonstrated that the intake of N. sativa significantly lowers blood pressure levels compared to control groups [2022]. Hence, black cumin oil (BCO), an extract of N. sativa, can be used to enhance the bioavailability and therapeutic activity of RP. This is due to the presence of a well-known bioactive compound called thymoquinone (TQ, Figure 1b) [23], which exerts antihypertensive effects by reducing ACE production [24,25]. The combination of RP and TQ can potentially offer synergistic antihypertensive benefits.

From a pharmaceutical perspective, BCO can be incorporated into SNEDDS formulations as a bioactive ingredient to improve the bioavailability of naturally occurring TQ, as well as the solubility and bioavailability of RP [10,26]. However, there is a need to develop an analytical method for quantifying the loaded drugs in the prepared SNEDDS formulation during its shelf-life and during its in vitro pharmaceutical characterization.

Furthermore, it is crucial to evaluate the potential toxicity of the detected degradation products [27]. Therefore, in silico studies were performed using computational methods, specifically Derek Nexus (version 6.3), to assess the potential toxicity and mutagenicity of the proposed compound. Derek Nexus (version 6.3) software is a specialized software specially adopted to assess various toxicity endpoints, such as carcinogenicity, genotoxicity, mutagenicity, teratogenicity, skin irritation, allergic reactions, and impact on fertility. The results from this study could be used as part of an ICH M7 workflow [28,29].

The main objective of this study was to develop a stability-indicating method for analyzing RP and TQ in the proposed formulation. The developed method was validated for linearity, specificity, accuracy, and precision. It was also tested for its ability to separate degradation products under different stress conditions. The established method was then employed as an analytical tool for quantifying the drugs in the proposed pharmaceutical formulation. Additionally, mass spectroscopy (MS) was utilized to identify the exact degradation products in the formulation. The degradation products’ chemical structures were further confirmed by in silico Zeneth Nexus software. Zeneth software uses a knowledge-based approach to forecast potential pathways for degradation and byproducts under various stress scenarios. Finally, the in silico prediction of toxicity for these degradation products was investigated using the Derek Nexus software.

2 Materials and methods

2.1 Materials

RP was purchased from Jai Radhe Sales (Ahmedabad, India). TQ was obtained from Sigma-Aldrich (St. Louis, MO, USA). Hydrogenated castor oil (HCO-30) was acquired from Nicole Chemical Co. (Tokyo, Japan). Transcutol P (TC-P) was obtained from Gattefossé (Lyon, France).

2.2 Preparation of BCO

The procedure for obtaining BCO was described in a previous publication [13]. In summary, black cumin seeds (BCS) were collected from the central part of Bangladesh. The collected seeds were cleaned using fresh water and then dried in open air with exposure to sunlight to remove all moisture. The dried seeds were then cold-pressed to extract the oil. The obtained oil was stored in an amber glass bottle with a screw cap, as shown in Figure 2.

2.3 Preparation of BCO-based SNEDDS formulation

The SNEDDS formulation was prepared following the procedure described in the literature [30]. In a 4 mL glass vial, HCO-30, TC, and BCO were accurately weighed in a ratio of 40:27.75:32.25 to create the RP-free bioactive SNEDDS. Afterward, 10 mg of RP was added to 990 mg of the RP-free SNEDDS and subjected to vortexing and sonication to ensure complete solubilization of the drug. The drug content, specifically RP and TQ, was determined using the developed ultrahigh-performance liquid chromatography (UPLC) method to quantify the initial concentrations accurately.

2.4 Preparation of mobile phase (solution A)

To prepare the mobile phase, 1 g of sodium lauryl sulfate was dissolved in a 1 L volumetric flask and then MQ water was added to prepare a 0.1% w/v solution. The pH of the solution was adjusted to 2.4 ± 0.1 using phosphoric acid. The solution was filtered through a 0.45 µm Millipore membrane filter. Acetonitrile (ACN) was then added to the filtered solution in a ratio of 55:45 v/v. The resulting mixture was further adjusted to a pH of 2.75 ± 0.1 using phosphoric acid, and this mixture was named Solution A.

2.5 Instrumentation and chromatographic conditions

The analysis of RP and TQ in the standard solutions, quality control samples, and bioactive SNEDDS formulations was carried out using the Waters Acquity UPLC system (Milford, MA, USA). The UPLC system consists of a binary solvent pump manager connected to a column chamber with controlled temperature. The samples were injected through an Acquity automatic Sample Manager and passed through a connected column. The drug concentrations were analyzed using the equipped Acquity photodiode array (PDA) detector. The mobile phase used for elution was prepared by combining Solution A and ACN in a ratio of 67:33. Separation was performed on an Acquity UPLC HSS T3 column (2.1 mm × 100 mm, 1.8 µm). The flow rate of the mobile phase was maintained at 0.25 mL/min. A sample volume of 2 µL was injected, and the absorbance of RP and TQ was detected at 210 and 254 nm, respectively.

2.6 Preparation of standard stock solution, calibration, and quality control samples

To prepare stock solutions of both drugs, 5 mg of each drug was dissolved in separate 10 mL volumetric flasks using ACN. This resulted in stock solutions with a concentration of 500 μg/mL for each drug. From the prepared stock solutions, serial dilutions were performed by diluting the stock solution with ACN to obtain the desired concentration range. For RP, the concentrations ranged from 1.5 to 50 μg/mL, and for TQ the concentrations ranged from 0.5 to 50 μg/mL.

2.7 Validation studies

2.7.1 Linearity and calibration

To construct the calibration curves, dilutions of RP and TQ with varying concentrations were prepared. These freshly prepared standard solutions were then injected in six replicates, and the resulting peak areas were recorded. The peak area is a measure of the response obtained from the UV absorbance of the compounds. Using the MassLynx software (Waters Corporation, Milford, MA, USA), the concentration of RP or TQ was plotted against the corresponding measured peak area. The linear regression equations were then calculated to determine the relationship between the drug concentration and absorbance. This included calculating parameters such as the slope, intercept, and correlation coefficient (r 2) of the calibration curves [31].

2.7.2 Specificity

The specificity of the developed analytical method demonstrates its capability to accurately determine the drug concentration even in the presence of other components. This encompasses assessing any potential interference, such as the matrix effect, between the retention time of the drug peak and other components. Matrix components were injected to evaluate method specificity, and the retention times of detected peaks were compared with those of the matrix spiked with RP and TQ. This analysis ensured that any potential interference was properly identified and avoided during drug concentration determination [32].

2.7.3 Limit of detection (LOD) and lower limit of quantification (LLOQ)

LOD and LLOQ were estimated based on the calculated standard deviation (SD) of responses and slope obtained from the calibration curve using the following equations:

LOD = ( 3.3 × SD ) / slope ,

LLOQ = ( 10 × SD ) / slope .

2.7.4 Accuracy and precision

Accuracy (% recovery) assessed the ability of the developed method to detect the drug concentration close to the predicted value. This was accomplished by comparing the theoretical concentration with the mean concentration of the injected sample, which was determined based on the constructed calibration curve. Precision (relative standard deviation, RSD%) was calculated to evaluate the method’s capability to consistently estimate the drug concentration close to its expected value. Typically, this was accomplished by comparing the standard deviation value of multiple injections to the mean of the results. In this study, quality control samples were injected six times over a period of 3 days. The recovery (%) and RSD% for each concentration were calculated to determine the accuracy and precision of the method, respectively.

2.7.5 Stability of the prepared standard solution

In order to assess the stability of the calibration curve under refrigeration conditions, two concentrations were selected for the study. The prepared solutions were stored in a freezer at −20°C, and the drug concentrations were analyzed using the freshly constructed calibration curve on a weekly basis. This allowed for monitoring any potential changes in the accuracy and reliability of the calibration curve over time in the refrigerated storage conditions.

2.8 Stability indicating study

A forced degradation study was conducted to evaluate the ability of the developed method to separate the RP and TQ peaks from any degradation peaks that may arise under various stress conditions. This involved subjecting RP and TQ solutions to oxidative, thermal, acid, and alkaline hydrolysis studies. Following the degradation process, the samples were filtered using a filter syringe and analyzed using the developed UPLC method.

2.9 Application of the developed method

A bioactive SNEDDS formulation, loaded with RP, was prepared to assess the concentrations of RP and TQ after exposure to stability storage conditions [33]. Initially, the concentrations of RP and TQ in the freshly prepared SNEDDS formulation were determined in order to calculate the initial drug concentration. The prepared SNEDDS formulation was then placed in a stability chamber under controlled conditions (40°C and 75% RH) and stored for a period of 2 months. At the end of this incubation period, the SNEDDS formulation from the stability chamber was retrieved, and a chromatogram of the formulation was obtained using the developed UPLC method to evaluate its effectiveness in separating the drugs from any potential degradation products.

2.10 Parameters for the MS scan

The degradation products for the stability sample were determined using a triple quadrupole (TQD) mass spectrometer. TQD was operated in positive electrospray ionization (ESI+) mode. The TQD was run in the MS scan mode over the range of 50–1,000 Da. The cone voltage was set as 33 V. The capillary voltage, extractor voltage, and RF lens were set at 3.3 kV, 3.0 V, and 0.1 V, respectively. The source temperature and desolvation temperature were set at 150 and 350°C, respectively. Nitrogen was used as the desolvation gas. The rate of desolvation gas flow was 600 L/H. The flow of cone gas was kept at 0.0 mL. The chromatographic conditions regarding the column and mobile phase composition were the same as those of the UV method to track the molecular weight of the compound peak at its exact location. The injection volume was 5 µL.

2.11 In silico prediction of the chemical structure and toxicity of the degradation products

A degradation prediction research was conducted using Zeneth software, version 9 (software introduced by Lhasa Limited) in a variety of circumstances. All the three observed DPs were correctly predicted by the adopted Zeneth software.

Lhasa Limited has introduced a software application named Derek Nexus, designed specifically for the assessment of chemical toxicity as well as mutagenicity. This tool employs a knowledge-based approach to generate predictions, allowing users to evaluate potential hazards associated with a chemical by analyzing various endpoints such as mutagenicity, teratogenicity, carcinogenicity, skin irritation, hepatotoxicity, and phototoxicity across different species. The chemical structure under investigation was input, and the prediction process was initiated by executing a setup command in Derek Nexus. Detailed explanations of the predictions can be found in Section 3.

3 Results and discussion

3.1 Optimization of the developed UPLC method

An initial investigation was conducted on various columns and different eluent mobile phases to determine the optimal system components for separating the drugs and potential degradation products. After each optimization, the prepared degradation samples of RP and TQ were injected to assess the separation of the parent drug peak from the degradation products. By employing an isocratic elution method with a mobile phase consisting of solution A and ACN in a ratio of 67:33, and using an HSS T3 column, it was possible to separate both drugs and their degradation peaks. Figure 3 depicts the detected peaks of RP and TQ under the optimized conditions, along with the UV spectrum analysis to identify the maximum wavelength (λmax) using the connected PDA mode. The figure clearly shows that both drugs have distinct λmax values, making it impossible to simultaneously determine RP and TQ at the same λmax unless the method’s sensitivity is compromised. As a result, RP and TQ were detected using different UV channels, specifically 210 and 254 nm, respectively, which aligned with previously published data [34,35]. The retention times of RP and TQ were found to be 1.69 and 2.84 min, respectively, with a total run time of 3.2 min.

Figure 2 
                  Preparation of BCO: (a) BCS, (b) BCO obtained from compressed BCS, and (c) BCO stored in an amber glass bottle to protect it from light.
Figure 2

Preparation of BCO: (a) BCS, (b) BCO obtained from compressed BCS, and (c) BCO stored in an amber glass bottle to protect it from light.

3.2 Method validation

3.2.1 Selectivity and system suitability

Figure 4a and 4b illustrates the chromatograms of the injected standard solutions of RP and TQ, respectively. In order to examine any potential interference from the matrix before validation, an RP-free bioactive SNEDDS sample (without BCO) was injected [36]. The obtained chromatogram, as shown in Figure 4, verifies the absence of any interference peaks at the retention times of RP and TQ. The analysis of both the UV spectrum and the matrix effect confirms that the detected peaks indeed correspond to the analyzed RP and TQ drugs.

Figure 3 
                     Detected chromatograms of (a) RP standard solution and (b) TQ standard solution along with their corresponding UV spectra.
Figure 3

Detected chromatograms of (a) RP standard solution and (b) TQ standard solution along with their corresponding UV spectra.

Figure 4 
                     Chromatograms of matrix extraction (RP-free bioactive SNEDDS formulation without BCO) against the counterpart spiked with (a) RP and (b) TQ. The detections were at 210 and 254 nm, respectively.
Figure 4

Chromatograms of matrix extraction (RP-free bioactive SNEDDS formulation without BCO) against the counterpart spiked with (a) RP and (b) TQ. The detections were at 210 and 254 nm, respectively.

3.2.2 Linearity

The validation parameters for RP and TQ were evaluated in accordance with the ICH guidelines. Standard solutions of RP and TQ were prepared and injected using the previously described UPLC method outlined in Section 3.1. Figure S1 shows the overlay chromatograms obtained from the injected RP and TQ standard solutions. Theoretical drug concentrations were plotted against the corresponding detected peak areas for RP and TQ, as depicted in Figure S1. The resulting calibration curves for RP and TQ demonstrated excellent linearity, as indicated by the coefficient of regression. The calibration curve for RP showed a linear relationship with an r 2 value of 0.9995 within the studied range of 0.5–50 ppm (Figure S2 and Table 1). The equation of the calibration curve, obtained with software, can be expressed as follows: y = 267.6 × x + 24.63. Table 2 presents the back calculation results of the injected replicates. The residual plot in Figure S2 indicates that the collected data were randomly scattered around the zero line, further confirming the linearity of the obtained results.

Table 1

Linear regression analysis of RP and TQ via the developed UPLC method

Parameter RP TQ
Linearity range (μg/mL) 1.5–50 0.5–50
Correlation coefficient (r 2) 0.9995 0.9998
LOD (μg/mL) 0.57 0.24
LLOQ (μg/mL) 1.73 0.73
Table 2

Percent recovery of RP and TQ

Theoretical concentration (μg/mL) Mean (μg/mL) Accuracy (%) Precision (RSD %)
RP
1.5 1.47 97.78 3.85
2.5 2.47 98.67 2.31
5 4.97 99.33 1.15
7.5 7.63 101.78 1.54
20 20.03 100.17 1.04
50 49.87 99.73 1.27
TQ
0.5 0.47 94.00 0.24
0.75 0.70 93.33 0.33
1.5 1.43 95.56 3.85
2.5 2.43 97.33 2.31
5 4.93 98.67 2.31
7.5 7.50 100.00 2.31
20 19.97 99.83 0.29
50 50.23 100.47 0.46

Regarding TQ, the standard calibration curve was established within the selected range of 0.05–50 ppm (Figure S2). Regression analysis revealed a calculated correlation coefficient (r 2) of 0.9998, indicating excellent linearity across the studied range. The equation of the calibration curve for TQ is represented as Y = 875.9X – 2.83. Additionally, Figure S2 illustrates the residual plot, confirming the linearity of the calibration curve by displaying a random distribution of data points around the zero line. Based on these findings, the developed method can be deemed reliable for the simultaneous determination of RP and TQ concentrations.

3.2.3 LOD and LLOQ

The LODs for RP and TQ were estimated via the calculated slope of intercept method from the constructed calibration curve and found to be 0.57 and 0.24 μg/mL, respectively. Correspondingly, the calculated LLOQs for both drugs were determined to be 1.73 and 0.73 μg/mL for RP and TQ, respectively. Moreover, the quality control sample prepared to represent LLOQ demonstrated good inter-day accuracy with % recoveries of 96.92 and 102.2 for RP and TQ, respectively. Additionally, the calculated RSD% found to be 1.56 and 6.12 for RP and TQ, respectively, indicates the acceptable precision of the developed UPLC method.

3.2.4 Accuracy and precision

To estimate the accuracy of the developed method, percentage recovery was calculated following the injection of quality control samples. In addition, the precision of the developed UPLC method was assessed to determine its repeatability. Five quality control samples were prepared for RP, consisting of concentrations of 1.5, 4.5, 10.0, 17.5, and 40.0 μg/mL, representing LLOQ, 3LLOQ, 20% upper limit, 35% upper limit, and 80% upper limit, respectively. Similarly, quality control samples were prepared for TQ with concentrations of 0.5, 1.5, 10.0, 17.5, and 40.0, representing LLOQ, 3LLOQ, 20% upper limit, 35% upper limit, and 80% upper limit, respectively. Table 3 presents the % recovery of these five concentrations with RSD % for intra- and inter-day measurements. The % recovery was found to range from 91.6 to 106.4%, and RSD% was less than 6.2%.

Table 3

Intra- and inter-day precision for the analysis of RP and TQ

Quality control sample Intra-day accuracy and precision Inter-day accuracy and precision
Accuracy (%) Precision (RSD%) Accuracy (%) Precision (RSD%)
RM
1.5 μg/mL 97.37 0.15 96.26 1.56
4.5 μg/mL 92.67 2.25 91.94 1.94
10.0 μg/mL 92.1 4.65 91.56 3.37
17.5 μg/mL 105.17 3.78 106.36 3.17
40.0 μg/mL 100.9 0.26 100.76 0.36
TQ
0.5 μg/mL 105 3.82 102.12 6.12
1.5 μg/mL 96.7 4.63 96.66 3.62
10.0 μg/mL 95.17 3.65 94.56 2.75
17.5 μg/mL 104.73 2.4 105.52 2.03
40.0 μg/mL 100.17 0.78 100.34 0.6

3.2.5 Stability of the calibration curve in a freezer

In order to assess the stability of the prepared calibration curve in a freezer, two concentrations (5 and 20 μg/mL) were chosen. The drug solutions were stored in amber vials with tight screw caps. Figure 5 illustrates the percentage recovery of the injected drug concentrations over a 2-week period. As shown in the figure, the recovered drug concentrations remained within the range of 90–110% after 1 week of storage, affirming the reliability of utilizing standard solutions for daily routine analysis. However, an additional week of storage (a total of 2 weeks) led to a significant decrease in drug concentrations. Consequently, it is recommended to prepare a fresh standard solution each week to ensure the accuracy of back-calculated data based on the constructed calibration curve.

Figure 5 
                     Histograms of back-calculated concentrations for the standard solution of (a) Ramipril and (b) Thymoquinone stored in the refrigerator for 2 weeks.
Figure 5

Histograms of back-calculated concentrations for the standard solution of (a) Ramipril and (b) Thymoquinone stored in the refrigerator for 2 weeks.

3.3 Forced degradation study

To investigate the effects of acid, alkaline, thermal, and oxidative hydrolysis on the prepared stock solutions of RP and TQ, they were incubated with 1 N hydrochloric acid, 1 N sodium hydroxide, pure water, and 6% hydrogen peroxide, respectively. The samples were then heated at 80 ° C for 2 h to accelerate hydrolysis under the tested conditions. Notably, the alkali-forced degradation study observed complete degradation of RP and TQ. Consequently, the samples were incubated at room temperature for approximately 15 min to detect the original parent peaks along with their corresponding degradation products. Figure 6 displays the chromatograms obtained following RP and TQ hydrolysis studies. Furthermore, the resolution value exceeded 1.5, indicating that both drugs were well separated without any interference [37]. These findings suggest that the developed method can accurately quantify both drugs even in the presence of degradation products. In addition, Table 4 summarizes the previously published stability-indicating methods in terms of the mobile phase used, column type, run time, and detected wavelength. Our method demonstrates a significantly shorter run time of just 3.5 min while effectively detecting both drugs and their degradation products, showcasing its superiority over the previously published methods.

Figure 6 
                  Chromatograms obtained from the forced degradation study, including (a and b) thermally treated, (c and d) acid-treated, (e and f) alkaline-treated, and (g and h) oxidative samples of RP and TQ, respectively.
Figure 6

Chromatograms obtained from the forced degradation study, including (a and b) thermally treated, (c and d) acid-treated, (e and f) alkaline-treated, and (g and h) oxidative samples of RP and TQ, respectively.

Table 4

Published stability-indicating methods used quantification of RP and TQ

Drug name Mobile phase Stationary phase Run time (min) Detection wavelength (nm) References
RP ACN + 100 mM sodium perchlorate solution (pH 2.5) SUPELCOSIL LC-8 column 8 210 [38]
10 mM ammonium acetate buffer (pH 6) + methanol cyanopropyl column 15 210 [39]
ACN + water C18 column 7 215 [40]
ACN + 50 mM ammonium acetate XBridge C18 column 6 240 [41]
ACN + 4.5 M sodium lauryl sulfate as buffer Zorbax XDB-C18 column 3 210 [34]
0.1% Sodium lauryl sulfate + ACN Acquity UPLC HSS T3 column 3.25 210 Current work
TQ Water + ACN HSS-T3 C18 column 3.5 294 [42]
0.1% Formic acid + methanol C18 column 12.5 254 [43]
0.1% Sodium lauryl sulfate + ACN Acquity UPLC HSS T3 column 3.25 254 Current work

3.4 Pharmaceutical application in characterization of developed SNEDDS formulation

To assess the pharmaceutical characteristics of the prepared RP-loaded bioactive SNEDDS formulation, its mixed components were examined for their ability to spontaneously form a nanoemulsion upon exposure to aqueous media in the gastrointestinal tract (GIT). The formulated mixture was diluted and mixed using a magnetic stirrer for a duration of 5 min. Subsequently, the particle size of the resulting dispersion system was measured using a Zetasizer, as depicted in Figure 7. It was observed that the dispersed system exhibited a nanosize range, with a PDI value lower than 0.3, indicating the uniformity and homogeneity of the dispersion system [44,45]. This finding suggests that the prepared formulation has the potential to enhance the bioavailability of both RP and TQ, leading to improved therapeutic outcomes in the treatment of hypertension [46,47].

Figure 7 
                  Histogram of particle size distribution of RP-loaded bioactive SNEDDS formulation dispersed in distilled water (1:1,000).
Figure 7

Histogram of particle size distribution of RP-loaded bioactive SNEDDS formulation dispersed in distilled water (1:1,000).

3.5 Application of UPLC

According to the existing literature, both RP and TQ are known to be sensitive to heat and humidity [48,49]. To assess the stability of the prepared RP-loaded bioactive SNEDDS, an accelerated study was conducted by subjecting it to incubation at 40°C/75%RH, aimed at enhancing the degradation of RP and TQ. Both drugs were extracted from the incubated formulation and subsequently injected to evaluate the capability of the established method to distinguish the parent drug peaks from the resulting degradation products. Figure 8 illustrates the chromatograms of stability samples at the selected channels (210 and 254 nm) used for the detection of RP and TQ, respectively. The figure clearly demonstrates that RP was completely degraded, as no peak was detected at the drug’s retention time. On the other hand, TQ’s peak was detected in the corresponding channel, with no detected degradation. Therefore, it can be concluded that the developed method successfully separated and quantified RP and TQ even in the presence of degradation products. The detected degradation products were subjected to mass scanning in order to identify their respective molecular weights. Figure 9 displays the molecular weights of the degradation products at 0.87, 1.00, and 2.76 min, which were measured as 156.98, 389.16, and 399.23, respectively. The molecular weight 421.18 can be assumed to be the sodium adduct of 398.22. The molecular weights of the three degradation products were extra confirmed by in silico Zeneth software. The Zeneth RP degradation prediction model suggests that the main factors responsible for RP degradation are amide hydrolysis, alkyl ester hydrolysis, and lactamization of the amino acid or derivative.

Figure 8 
                  Chromatograms obtained from RP- and TQ-loaded bioactive SNEDDS incubated at 40°C with 75% RH for 2 months.
Figure 8

Chromatograms obtained from RP- and TQ-loaded bioactive SNEDDS incubated at 40°C with 75% RH for 2 months.

Figure 9 
                  Mass spectra of detected degradation products at (a) 0.87, (b) 1.00, and (c) 2.76 min.
Figure 9

Mass spectra of detected degradation products at (a) 0.87, (b) 1.00, and (c) 2.76 min.

The results are displayed in Table 5, showing the molecular weights of the degradation products, the stress condition for their formation, and the transformation name.

Table 5

Practically observed and theoretically predicted degradation products by Zeneth software for RP

Name Transformation name Conditions Exact mass
D1 Hydrolysis of amide Water; pH 155.0946
D2 Hydrolysis of alkyl ester Water; pH 388.1998
D3 Lactamization of the amino acid or derivative pH, Temperature 398.2206

3.6 In silico toxicity prediction of the alkaline degradation products of RP

The toxicity and mutagenicity of the alkaline degradation products of RP were estimated using the Derek (version 6.3). Table 6 presents the results of toxicity and mutagenicity studies performed. Predictions were generated by employing various criteria, encompassing humans, monkeys, pigs, dogs, rabbits, guinea hamsters, mice, primates, rats, bacteria, and Salmonella typhimurium. Multiple endpoints, including carcinogenicity, chromosomal damage, hepatotoxicity, skin sensitization, teratogenicity, nephrotoxicity, neurotoxicity, phototoxicity, phospholipidosis, and numerous disorders, were calculated as part of the analysis. The following conclusions are here: the first degradation product of PR (retention time = 1.00 min) was anticipated to induce hepatotoxicity and teratogenicity due to N-acyl-pyrrolidine, -piperidine, or their analogue. But this group was also found in RP; accordingly, the toxicity of other alkaline degradation products is comparable to the main drug. The other two degradation products (retention times = 0.87 and 2.76 min) showed no toxicity.

Table 6

Toxicity and mutagenicity prediction of alkaline degradation products of RP

Derek
Chemical structure Structural alert code Structural alert Endpoints for toxicity
562
Teratogenicity
614
Hepatotoxicity
No detected toxicity
No detected toxicity

4 Conclusions

A validated UPLC method for the simultaneous estimation of RP and TQ and their degradation products has been successfully established. The results obtained from method validation demonstrated good linearity, accuracy, and precision, ensuring the reliability of the developed method. Furthermore, our proposed RP-loaded bioactive SNEDDS formulation displayed the ability to form a nanoemulsion upon dispersion. Standard solutions of RP and TQ were subjected to various stress conditions, including acid, alkaline, thermal, and oxidative hydrolysis, to evaluate the stability and degradation behavior of the drugs. The developed method effectively separated the parent drug peaks from the formed degradation products, enabling accurate quantification. Additionally, the validated method was employed to estimate the levels of both drugs in the formulation after exposure to these stress conditions. Moreover, we employed the Derek software to evaluate the in silico toxicity of the alkaline degradation products of RP. The predicted outcomes indicated limited toxicity, notably hepatotoxicity and teratogenicity, associated with the first degradation product. The present study revealed that the developed UPLC method indicated that direct contact between the SNEDDS formulation and RP resulted in the formation of toxicological degradation products during storage. Therefore, an alternative approach should be used to enhance the dissolution and bioavailability of RP with no impact on the safety of treated patients.

Acknowledgements

The authors extend their appreciation to Researchers Supporting Project number (RSPD2024R1002), King Saud University, Riyadh, Saudi Arabia.

  1. Funding information: The authors extend their appreciation to Researchers Supporting Project number (RSPD2024R1002), King Saud University, Riyadh, Saudi Arabia.

  2. Author contributions: Conceptualization – E.M.E., A.A.S., and M.K.; methodology – E.M.E. and A.Y.S.; software – E.M.E., A.Y.S., and H.W.D.; validation – E.M.E.; formal analysis – E.M.E.; investigation – E.M.E., A.Y.S., and A.A.S.; resources – M.K.; data curation – E.M.E.; writing – original draft preparation – E.M.E., A.Y.S., and H.W.D.; writing – review and editing – E.M.E., A.A.S., A.Y.S., and M.A.; visualization – E.M.E. and A.Y.S.; supervision – E.M.E.; project administration – E.M.E.; funding acquisition – E.M.E. All authors have read and agreed to the published version of the manuscript.

  3. Conflict of interest: The authors state no conflict of interest.

  4. Ethical approval: The conducted research is not related to either human or animal use.

  5. Data availability statement: Data will be made available on request.

References

[1] Bhalani DV, Nutan B, Kumar A, Singh Chandel AK. Bioavailability enhancement techniques for poorly aqueous soluble drugs and therapeutics. Biomedicines. 2022;10(9):2055.10.3390/biomedicines10092055Search in Google Scholar PubMed PubMed Central

[2] Kesharwani R, Jaiswal P, Patel DK, Yadav PK. Lipid-based drug delivery system (LBDDS): An emerging paradigm to enhance oral bioavailability of poorly soluble drugs. Biomed Mater Devices. 2023;1(2):648–63.10.1007/s44174-022-00041-0Search in Google Scholar

[3] Kumar M, Kumar D, Kumar S, Kumar A, Mandal UK. A recent review on bio-availability enhancement of poorly water-soluble drugs by using bioenhancer and nanoparticulate drug delivery system. Curr Pharm Des. 2022;28(39):3212–24.10.2174/1381612829666221021152354Search in Google Scholar PubMed

[4] Wu Y, Levons J, Narang AS, Raghavan K, Rao VM. Reactive impurities in excipients: Profiling, identification and mitigation of drug–excipient incompatibility. Aaps Pharmscitech. 2011;12:1248–63.10.1208/s12249-011-9677-zSearch in Google Scholar PubMed PubMed Central

[5] Bharate SS, Bharate SB, Bajaj AN. Interactions and incompatibilities of pharmaceutical excipients with active pharmaceutical ingredients: A comprehensive review. J Excip Food Chem. 2016;1(3):3–26.Search in Google Scholar

[6] Sharma A, Madhunapantula SV, Robertson GP. Toxicological considerations when creating nanoparticle-based drugs and drug delivery systems. Expert Opin Drug Metab Toxicol. 2012;8(1):47–69.10.1517/17425255.2012.637916Search in Google Scholar PubMed PubMed Central

[7] Vuong AD, Annis LG. Ramipril for the prevention and treatment of cardiovascular disease. Ann Pharmacother. 2003;37(3):412–9.10.1345/aph.1C262Search in Google Scholar PubMed

[8] Abouelkheir M. Evaluation of dual inhibitory effect of anagliptin, ramipril and lisinopril on angiotensin-converting enzyme and DPP-4 activities. Curr Mol Pharmacol. 2022;15(3):582–8.10.2174/1874467214666210601104117Search in Google Scholar PubMed

[9] Shafiq S, Shakeel F, Talegaonkar S, Ahmad FJ, Khar RK, Ali M. Design and development of oral oil in water ramipril nanoemulsion formulation: In vitro and in vivo assessment. J Biomed Nanotechnol. 2007;3(1):28–44.10.1166/jbn.2007.008Search in Google Scholar

[10] Alhasani KF, Kazi M, Ibrahim MA, Shahba AA, Alanazi FK. Self-nanoemulsifying ramipril tablets: A novel delivery system for the enhancement of drug dissolution and stability. Int J Nanomed. 2019;5435–48.10.2147/IJN.S203311Search in Google Scholar PubMed PubMed Central

[11] Madhavi K, Shikha A, Yadav JK. Self-nano emulsifying drug delivery system of ramipril: Formulation and in vitro evaluation. Int J Pharm Pharm Sci. 2016;8(4):291–6.Search in Google Scholar

[12] Jayapal N, Vishnu YV. Formulation and in vivo evaluation of self-nanoemulsifying drug delivery system of ramipril in wistar rats. Asian J Pharm Clin Res. 2021;14(7):126–36.10.22159/ajpcr.2021.v14i7.42003Search in Google Scholar

[13] Shahba AA-W, Sherif AY, Elzayat EM, Kazi M. Combined ramipril and black seed oil dosage forms using bioactive self-nanoemulsifying drug delivery systems (BIO-SNEDDSs). Pharmaceuticals. 2022;15(9):1120.10.3390/ph15091120Search in Google Scholar PubMed PubMed Central

[14] Shafiq S, Shakeel F. Effect of labrasol on self-nanoemulsification efficiency of ramipril nanoemulsion. Die Pharmazie-Int J Pharm Sci. 2009;64(12):812–7.Search in Google Scholar

[15] Shafiq S, Shakeel F. Stability and self-nanoemulsification efficiency of ramipril nanoemulsion containing labrasol and plurol oleique. Clin Res Regul Aff. 2010;27(1):7–12.10.3109/10601330903571691Search in Google Scholar

[16] Kazi M, Alhajri A, Alshehri SM, Elzayat EM, Al Meanazel OT, Shakeel F, et al. Enhancing oral bioavailability of apigenin using a bioactive self-nanoemulsifying drug delivery system (Bio-SNEDDS): In vitro, in vivo and stability evaluations. Pharmaceutics. 2020;12(8):749.10.3390/pharmaceutics12080749Search in Google Scholar PubMed PubMed Central

[17] Kazi M, Shahba AA, Alrashoud S, Alwadei M, Sherif AY, Alanazi FK. Bioactive self-nanoemulsifying drug delivery systems (Bio-SNEDDS) for combined oral delivery of curcumin and piperine. Molecules. 2020;25(7):1703.10.3390/molecules25071703Search in Google Scholar PubMed PubMed Central

[18] Yimer EM, Tuem KB, Karim A, Ur-Rehman N, Anwar F. Nigella sativa L.(black cumin): A promising natural remedy for wide range of illnesses. Evid-Based Complement Altern Med. 2019;2019:1–16.10.1155/2019/1528635Search in Google Scholar PubMed PubMed Central

[19] Majeed A, Muhammad Z, Ahmad H, Hayat SSS, Inayat N, Siyyar S. Nigella sativa L.: Uses in traditional and contemporary medicines–An overview. Acta Ecol Sin. 2021;41(4):253–8.10.1016/j.chnaes.2020.02.001Search in Google Scholar

[20] Shoaei‐Hagh P, Kamelan Kafi F, Najafi S, Zamanzadeh M, Heidari Bakavoli A, Ramezani J, et al. A randomized, double‐blind, placebo‐controlled, clinical trial to evaluate the benefits of Nigella sativa seeds oil in reducing cardiovascular risks in hypertensive patients. Phytother Res. 2021;35(8):4388–400.10.1002/ptr.7140Search in Google Scholar PubMed

[21] Fallah Huseini H, Amini M, Mohtashami R, Ghamarchehre M, Sadeqhi Z, Kianbakht S, et al. Blood pressure lowering effect of Nigella sativa L. seed oil in healthy volunteers: A randomized, double‐blind, placebo‐controlled clinical trial. Phytother Res. 2013;27(12):1849–53.10.1002/ptr.4944Search in Google Scholar PubMed

[22] Dehkordi FR, Kamkhah AF. Antihypertensive effect of Nigella sativa seed extract in patients with mild hypertension. Fundam Clin Pharmacol. 2008;22(4):447–52.10.1111/j.1472-8206.2008.00607.xSearch in Google Scholar PubMed

[23] Sherif AY, Shahba AA-W. Development of a multifunctional oral dosage form via integration of solid dispersion technology with a black seed oil-based self-nanoemulsifying drug delivery system. Biomedicines. 2023;11(10):2733.10.3390/biomedicines11102733Search in Google Scholar PubMed PubMed Central

[24] Ahmad A, Raish M, Alkharfy KM. The potential role of thymoquinone in preventing the cardiovascular complications of COVID-19. Vasc Pharmacol. 2021;141:106899.10.1016/j.vph.2021.106899Search in Google Scholar PubMed PubMed Central

[25] Enayatfard L, Mohebbati R, Niazmand S, Hosseini M, Shafei MN. The standardized extract of Nigella sativa and its major ingredient, thymoquinone, ameliorates angiotensin II-induced hypertension in rats. J Basic Clin Physiol Pharmacol. 2018;30(1):51–8.10.1515/jbcpp-2018-0074Search in Google Scholar PubMed

[26] Rathore C, Hemrajani C, Sharma AK, Gupta PK, Jha NK, Aljabali AA, et al. Self-nanoemulsifying drug delivery system (SNEDDS) mediated improved oral bioavailability of thymoquinone: optimization, characterization, pharmacokinetic, and hepatotoxicity studies. Drug Deliv Transl Res. 2023;13(1):292–307.10.1007/s13346-022-01193-8Search in Google Scholar PubMed PubMed Central

[27] Devrukhakar PS, Shankar MS, Shankar G, Srinivas R. A stability-indicating LC–MS/MS method for zidovudine: Identification, characterization and toxicity prediction of two major acid degradation products. J Pharm Anal. 2017;7(4):231–6.10.1016/j.jpha.2017.01.006Search in Google Scholar PubMed PubMed Central

[28] Guideline IH, editor. Assessment and control of dna reactive (mutagenic) impurities in pharmaceuticals to limit potential carcinogenic risk M7. International conference on harmonization of technical requirements for registration of pharmaceuticals for human use (ICH). Geneva; 2014.Search in Google Scholar

[29] Ali AM, Alanazi MM, Attwa MW, Darwish HW. Selective stability indicating liquid chromatographic method based on quality by design framework and in silico toxicity assessment for infigratinib and its degradation products. Molecules. 2023;28(22):7476.10.3390/molecules28227476Search in Google Scholar PubMed PubMed Central

[30] Nazlı H, Mesut B, Özsoy Y. In vitro evaluation of a solid supersaturated self nanoemulsifying drug delivery system (Super-SNEDDS) of aprepitant for enhanced solubility. Pharmaceuticals. 2021;14(11):1089.10.3390/ph14111089Search in Google Scholar PubMed PubMed Central

[31] Proença P, Mustra C, Marcos M, Franco JM, Corte-Real F, Vieira DN. Validated UPLC-MS/MS assay for the determination of synthetic phosphodiesterase type-5 inhibitors in postmortem blood samples. J Forensic Leg Med. 2013;20(6):655–8.10.1016/j.jflm.2013.03.002Search in Google Scholar PubMed

[32] Ibrahim M, Alhabib NA, Alshora D, Bekhit MMS, Taha E, Mahdi WA, et al. Application of quality by design approach in the optimization and development of the UPLC analytical method for determination of fusidic acid in pharmaceutical products. Separations. 2023;10(5):318.10.3390/separations10050318Search in Google Scholar

[33] Shahba AA, Alanazi FK, Mohsin K, Abdel-Hamid M. Stability assessment of cinnarizine in self-emulsifying drug delivery systems. Lat Am J Pharm. 2012;31(4):549–54.Search in Google Scholar

[34] Seshadri RK, Desai MM, Raghavaraju TV, Krishnan D, Rao DV, Chakravarthy IE. Simultaneous quantitative determination of metoprolol, atorvastatin and ramipril in capsules by a validated stability-indicating RP-UPLC method. Sci Pharm. 2010;78(4):821–34.10.3797/scipharm.1004-14Search in Google Scholar PubMed PubMed Central

[35] Kazi M, Shariare MH, Al-Bgomi M, Hussain MD, Alanazi FK. Simultaneous determination of curcumin (Cur) and thymoquinone (THQ) in lipid based self-nanoemulsifying systems and its application to the commercial product using UHPLC-UV-Vis spectrophotometer. Curr Pharm Anal. 2018;14(3):277–85.10.2174/1573412913666170331114232Search in Google Scholar

[36] Elzayat EM, Ibrahim MF, Abdel-Rahman AA, Ahmed SM, Alanazi FK, Habib WA. A validated stability-indicating UPLC method for determination of diclofenac sodium in its pure form and matrix formulations. Arab J Chem. 2017;10:S3245–54.10.1016/j.arabjc.2013.12.022Search in Google Scholar

[37] Al-Rifai N, Alshishani A, Darras F, Taha O, Abu-Jalloud S, Shaghlil L, et al. Solriamfetol impurities: Synthesis, characterization, and analytical method (UPLC-UV) validation. J Pharm Anal. 2023;13(4):403–11.10.1016/j.jpha.2023.02.012Search in Google Scholar PubMed PubMed Central

[38] Belal F, Al-Zaagi I, Gadkariem E, Abounassif M. A stability-indicating LC method for the simultaneous determination of ramipril and hydrochlorothiazide in dosage forms. J Pharm Biomed Anal. 2001;24(3):335–42.10.1016/S0731-7085(00)00474-XSearch in Google Scholar PubMed

[39] Elshanawane AA, Mostafa SM, Elgawish MS. Application of a validated, stability-indicating LC method to stress degradation studies of ramipril and moexipril. HCl. Chromatographia. 2008;67:567–73.10.1365/s10337-008-0544-3Search in Google Scholar

[40] Lakshmi K, Sivasubramanian L. A stability indicating HPLC method for the simultaneous determination of valsartan and ramipril in binary combination. J Chil Chem Soc. 2010;55(2):223–6.10.4067/S0717-97072010000200017Search in Google Scholar

[41] Koralla S, Konidala SK, Rao KG, Begum SM. Stability indicating RP-HPLC method for simultaneous estimation of ramipril and amlodipine besylate in pharmaceutical dosage form. Asian J Pharm Res. 2016;6(4):242–9.10.5958/2231-5691.2016.00034.4Search in Google Scholar

[42] Pathan SA, Jain GK, Zaidi SM, Akhter S, Vohora D, Chander P, et al. Stability‐indicating ultra‐performance liquid chromatography method for the estimation of thymoquinone and its application in biopharmaceutical studies. Biomed Chromatogr. 2011;25(5):613–20.10.1002/bmc.1492Search in Google Scholar PubMed

[43] Soliman RM, Salam RAA, Eid BG, Khayyat A, Neamatallah T, Mesbah MK, et al. Stability study of thymoquinone, carvacrol and thymol using HPLC-UV and LC-ESI-MS. Acta Pharm. 2020;70(3):325–42.10.2478/acph-2020-0028Search in Google Scholar PubMed

[44] Danaei M, Dehghankhold M, Ataei S, Hasanzadeh Davarani F, Javanmard R, Dokhani A, et al. Impact of particle size and polydispersity index on the clinical applications of lipidic nanocarrier systems. Pharmaceutics. 2018;10(2):57.10.3390/pharmaceutics10020057Search in Google Scholar PubMed PubMed Central

[45] Aguilar-Pérez KM, Medina DI, Parra-Saldívar R, Iqbal HM. Nano-size characterization and antifungal evaluation of essential oil molecules-loaded nanoliposomes. Molecules. 2022;27(17):5728.10.3390/molecules27175728Search in Google Scholar PubMed PubMed Central

[46] Shafiq S, Shakeel F, Talegaonkar S, Ahmad FJ, Khar RK, Ali M. Development and bioavailability assessment of ramipril nanoemulsion formulation. Eur J Pharm Biopharm. 2007;66(2):227–43.10.1016/j.ejpb.2006.10.014Search in Google Scholar PubMed

[47] Khan R, Nautiyal H, Saleem S. Thymoquinone-loaded nanocarriers for healthcare applications. Biomarkers as targeted herbal drug discovery. Apple Academic Press; 2021. p. 301–22.10.1201/9781003045526-13Search in Google Scholar

[48] Agbaria R, Gabarin A, Dahan A, Ben-Shabat S. Anticancer activity of Nigella sativa (black seed) and its relationship with the thermal processing and quinone composition of the seed. Drug Des Dev Ther. 2015;9:3119–24.10.2147/DDDT.S82938Search in Google Scholar PubMed PubMed Central

[49] Shafiq S, Shakeel F, Talegaonkar S, Khar RK, Ali M. Nanoemulsion as carrier for stability enhancement of ramipril. J Dispers Sci Technol. 2010;31(7):975–9.10.1080/01932690903224144Search in Google Scholar

Received: 2024-02-04
Revised: 2024-07-07
Accepted: 2024-07-12
Published Online: 2024-08-02

© 2024 the author(s), published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Regular Articles
  2. Porous silicon nanostructures: Synthesis, characterization, and their antifungal activity
  3. Biochar from de-oiled Chlorella vulgaris and its adsorption on antibiotics
  4. Phytochemicals profiling, in vitro and in vivo antidiabetic activity, and in silico studies on Ajuga iva (L.) Schreb.: A comprehensive approach
  5. Synthesis, characterization, in silico and in vitro studies of novel glycoconjugates as potential antibacterial, antifungal, and antileishmanial agents
  6. Sonochemical synthesis of gold nanoparticles mediated by potato starch: Its performance in the treatment of esophageal cancer
  7. Computational study of ADME-Tox prediction of selected phytochemicals from Punica granatum peels
  8. Phytochemical analysis, in vitro antioxidant and antifungal activities of extracts and essential oil derived from Artemisia herba-alba Asso
  9. Two triazole-based coordination polymers: Synthesis and crystal structure characterization
  10. Phytochemical and physicochemical studies of different apple varieties grown in Morocco
  11. Synthesis of multi-template molecularly imprinted polymers (MT-MIPs) for isolating ethyl para-methoxycinnamate and ethyl cinnamate from Kaempferia galanga L., extract with methacrylic acid as functional monomer
  12. Nutraceutical potential of Mesembryanthemum forsskaolii Hochst. ex Bioss.: Insights into its nutritional composition, phytochemical contents, and antioxidant activity
  13. Evaluation of influence of Butea monosperma floral extract on inflammatory biomarkers
  14. Cannabis sativa L. essential oil: Chemical composition, anti-oxidant, anti-microbial properties, and acute toxicity: In vitro, in vivo, and in silico study
  15. The effect of gamma radiation on 5-hydroxymethylfurfural conversion in water and dimethyl sulfoxide
  16. Hollow mushroom nanomaterials for potentiometric sensing of Pb2+ ions in water via the intercalation of iodide ions into the polypyrrole matrix
  17. Determination of essential oil and chemical composition of St. John’s Wort
  18. Computational design and in vitro assay of lantadene-based novel inhibitors of NS3 protease of dengue virus
  19. Anti-parasitic activity and computational studies on a novel labdane diterpene from the roots of Vachellia nilotica
  20. Microbial dynamics and dehydrogenase activity in tomato (Lycopersicon esculentum Mill.) rhizospheres: Impacts on growth and soil health across different soil types
  21. Correlation between in vitro anti-urease activity and in silico molecular modeling approach of novel imidazopyridine–oxadiazole hybrids derivatives
  22. Spatial mapping of indoor air quality in a light metro system using the geographic information system method
  23. Iron indices and hemogram in renal anemia and the improvement with Tribulus terrestris green-formulated silver nanoparticles applied on rat model
  24. Integrated track of nano-informatics coupling with the enrichment concept in developing a novel nanoparticle targeting ERK protein in Naegleria fowleri
  25. Cytotoxic and phytochemical screening of Solanum lycopersicum–Daucus carota hydro-ethanolic extract and in silico evaluation of its lycopene content as anticancer agent
  26. Protective activities of silver nanoparticles containing Panax japonicus on apoptotic, inflammatory, and oxidative alterations in isoproterenol-induced cardiotoxicity
  27. pH-based colorimetric detection of monofunctional aldehydes in liquid and gas phases
  28. Investigating the effect of resveratrol on apoptosis and regulation of gene expression of Caco-2 cells: Unravelling potential implications for colorectal cancer treatment
  29. Metformin inhibits knee osteoarthritis induced by type 2 diabetes mellitus in rats: S100A8/9 and S100A12 as players and therapeutic targets
  30. Effect of silver nanoparticles formulated by Silybum marianum on menopausal urinary incontinence in ovariectomized rats
  31. Synthesis of new analogs of N-substituted(benzoylamino)-1,2,3,6-tetrahydropyridines
  32. Response of yield and quality of Japonica rice to different gradients of moisture deficit at grain-filling stage in cold regions
  33. Preparation of an inclusion complex of nickel-based β-cyclodextrin: Characterization and accelerating the osteoarthritis articular cartilage repair
  34. Empagliflozin-loaded nanomicelles responsive to reactive oxygen species for renal ischemia/reperfusion injury protection
  35. Preparation and pharmacodynamic evaluation of sodium aescinate solid lipid nanoparticles
  36. Assessment of potentially toxic elements and health risks of agricultural soil in Southwest Riyadh, Saudi Arabia
  37. Theoretical investigation of hydrogen-rich fuel production through ammonia decomposition
  38. Biosynthesis and screening of cobalt nanoparticles using citrus species for antimicrobial activity
  39. Investigating the interplay of genetic variations, MCP-1 polymorphism, and docking with phytochemical inhibitors for combatting dengue virus pathogenicity through in silico analysis
  40. Ultrasound induced biosynthesis of silver nanoparticles embedded into chitosan polymers: Investigation of its anti-cutaneous squamous cell carcinoma effects
  41. Copper oxide nanoparticles-mediated Heliotropium bacciferum leaf extract: Antifungal activity and molecular docking assays against strawberry pathogens
  42. Sprouted wheat flour for improving physical, chemical, rheological, microbial load, and quality properties of fino bread
  43. Comparative toxicity assessment of fisetin-aided artificial intelligence-assisted drug design targeting epibulbar dermoid through phytochemicals
  44. Acute toxicity and anti-inflammatory activity of bis-thiourea derivatives
  45. Anti-diabetic activity-guided isolation of α-amylase and α-glucosidase inhibitory terpenes from Capsella bursa-pastoris Linn.
  46. GC–MS analysis of Lactobacillus plantarum YW11 metabolites and its computational analysis on familial pulmonary fibrosis hub genes
  47. Green formulation of copper nanoparticles by Pistacia khinjuk leaf aqueous extract: Introducing a novel chemotherapeutic drug for the treatment of prostate cancer
  48. Improved photocatalytic properties of WO3 nanoparticles for Malachite green dye degradation under visible light irradiation: An effect of La doping
  49. One-pot synthesis of a network of Mn2O3–MnO2–poly(m-methylaniline) composite nanorods on a polypyrrole film presents a promising and efficient optoelectronic and solar cell device
  50. Groundwater quality and health risk assessment of nitrate and fluoride in Al Qaseem area, Saudi Arabia
  51. A comparative study of the antifungal efficacy and phytochemical composition of date palm leaflet extracts
  52. Processing of alcohol pomelo beverage (Citrus grandis (L.) Osbeck) using saccharomyces yeast: Optimization, physicochemical quality, and sensory characteristics
  53. Specialized compounds of four Cameroonian spices: Isolation, characterization, and in silico evaluation as prospective SARS-CoV-2 inhibitors
  54. Identification of a novel drug target in Porphyromonas gingivalis by a computational genome analysis approach
  55. Physico-chemical properties and durability of a fly-ash-based geopolymer
  56. FMS-like tyrosine kinase 3 inhibitory potentials of some phytochemicals from anti-leukemic plants using computational chemical methodologies
  57. Wild Thymus zygis L. ssp. gracilis and Eucalyptus camaldulensis Dehnh.: Chemical composition, antioxidant and antibacterial activities of essential oils
  58. 3D-QSAR, molecular docking, ADMET, simulation dynamic, and retrosynthesis studies on new styrylquinolines derivatives against breast cancer
  59. Deciphering the influenza neuraminidase inhibitory potential of naturally occurring biflavonoids: An in silico approach
  60. Determination of heavy elements in agricultural regions, Saudi Arabia
  61. Synthesis and characterization of antioxidant-enriched Moringa oil-based edible oleogel
  62. Ameliorative effects of thistle and thyme honeys on cyclophosphamide-induced toxicity in mice
  63. Study of phytochemical compound and antipyretic activity of Chenopodium ambrosioides L. fractions
  64. Investigating the adsorption mechanism of zinc chloride-modified porous carbon for sulfadiazine removal from water
  65. Performance repair of building materials using alumina and silica composite nanomaterials with electrodynamic properties
  66. Effects of nanoparticles on the activity and resistance genes of anaerobic digestion enzymes in livestock and poultry manure containing the antibiotic tetracycline
  67. Effect of copper nanoparticles green-synthesized using Ocimum basilicum against Pseudomonas aeruginosa in mice lung infection model
  68. Cardioprotective effects of nanoparticles green formulated by Spinacia oleracea extract on isoproterenol-induced myocardial infarction in mice by the determination of PPAR-γ/NF-κB pathway
  69. Anti-OTC antibody-conjugated fluorescent magnetic/silica and fluorescent hybrid silica nanoparticles for oxytetracycline detection
  70. Curcumin conjugated zinc nanoparticles for the treatment of myocardial infarction
  71. Identification and in silico screening of natural phloroglucinols as potential PI3Kα inhibitors: A computational approach for drug discovery
  72. Exploring the phytochemical profile and antioxidant evaluation: Molecular docking and ADMET analysis of main compounds from three Solanum species in Saudi Arabia
  73. Unveiling the molecular composition and biological properties of essential oil derived from the leaves of wild Mentha aquatica L.: A comprehensive in vitro and in silico exploration
  74. Analysis of bioactive compounds present in Boerhavia elegans seeds by GC-MS
  75. Homology modeling and molecular docking study of corticotrophin-releasing hormone: An approach to treat stress-related diseases
  76. LncRNA MIR17HG alleviates heart failure via targeting MIR17HG/miR-153-3p/SIRT1 axis in in vitro model
  77. Development and validation of a stability indicating UPLC-DAD method coupled with MS-TQD for ramipril and thymoquinone in bioactive SNEDDS with in silico toxicity analysis of ramipril degradation products
  78. Biosynthesis of Ag/Cu nanocomposite mediated by Curcuma longa: Evaluation of its antibacterial properties against oral pathogens
  79. Development of AMBER-compliant transferable force field parameters for polytetrafluoroethylene
  80. Treatment of gestational diabetes by Acroptilon repens leaf aqueous extract green-formulated iron nanoparticles in rats
  81. Development and characterization of new ecological adsorbents based on cardoon wastes: Application to brilliant green adsorption
  82. A fast, sensitive, greener, and stability-indicating HPLC method for the standardization and quantitative determination of chlorhexidine acetate in commercial products
  83. Assessment of Se, As, Cd, Cr, Hg, and Pb content status in Ankang tea plantations of China
  84. Effect of transition metal chloride (ZnCl2) on low-temperature pyrolysis of high ash bituminous coal
  85. Evaluating polyphenol and ascorbic acid contents, tannin removal ability, and physical properties during hydrolysis and convective hot-air drying of cashew apple powder
  86. Development and characterization of functional low-fat frozen dairy dessert enhanced with dried lemongrass powder
  87. Scrutinizing the effect of additive and synergistic antibiotics against carbapenem-resistant Pseudomonas aeruginosa
  88. Preparation, characterization, and determination of the therapeutic effects of copper nanoparticles green-formulated by Pistacia atlantica in diabetes-induced cardiac dysfunction in rat
  89. Antioxidant and antidiabetic potentials of methoxy-substituted Schiff bases using in vitro, in vivo, and molecular simulation approaches
  90. Anti-melanoma cancer activity and chemical profile of the essential oil of Seseli yunnanense Franch
  91. Molecular docking analysis of subtilisin-like alkaline serine protease (SLASP) and laccase with natural biopolymers
  92. Overcoming methicillin resistance by methicillin-resistant Staphylococcus aureus: Computational evaluation of napthyridine and oxadiazoles compounds for potential dual inhibition of PBP-2a and FemA proteins
  93. Exploring novel antitubercular agents: Innovative design of 2,3-diaryl-quinoxalines targeting DprE1 for effective tuberculosis treatment
  94. Drimia maritima flowers as a source of biologically potent components: Optimization of bioactive compound extractions, isolation, UPLC–ESI–MS/MS, and pharmacological properties
  95. Estimating molecular properties, drug-likeness, cardiotoxic risk, liability profile, and molecular docking study to characterize binding process of key phyto-compounds against serotonin 5-HT2A receptor
  96. Fabrication of β-cyclodextrin-based microgels for enhancing solubility of Terbinafine: An in-vitro and in-vivo toxicological evaluation
  97. Phyto-mediated synthesis of ZnO nanoparticles and their sunlight-driven photocatalytic degradation of cationic and anionic dyes
  98. Monosodium glutamate induces hypothalamic–pituitary–adrenal axis hyperactivation, glucocorticoid receptors down-regulation, and systemic inflammatory response in young male rats: Impact on miR-155 and miR-218
  99. Quality control analyses of selected honey samples from Serbia based on their mineral and flavonoid profiles, and the invertase activity
  100. Eco-friendly synthesis of silver nanoparticles using Phyllanthus niruri leaf extract: Assessment of antimicrobial activity, effectiveness on tropical neglected mosquito vector control, and biocompatibility using a fibroblast cell line model
  101. Green synthesis of silver nanoparticles containing Cichorium intybus to treat the sepsis-induced DNA damage in the liver of Wistar albino rats
  102. Quality changes of durian pulp (Durio ziberhinus Murr.) in cold storage
  103. Study on recrystallization process of nitroguanidine by directly adding cold water to control temperature
  104. Determination of heavy metals and health risk assessment in drinking water in Bukayriyah City, Saudi Arabia
  105. Larvicidal properties of essential oils of three Artemisia species against the chemically insecticide-resistant Nile fever vector Culex pipiens (L.) (Diptera: Culicidae): In vitro and in silico studies
  106. Design, synthesis, characterization, and theoretical calculations, along with in silico and in vitro antimicrobial proprieties of new isoxazole-amide conjugates
  107. The impact of drying and extraction methods on total lipid, fatty acid profile, and cytotoxicity of Tenebrio molitor larvae
  108. A zinc oxide–tin oxide–nerolidol hybrid nanomaterial: Efficacy against esophageal squamous cell carcinoma
  109. Research on technological process for production of muskmelon juice (Cucumis melo L.)
  110. Physicochemical components, antioxidant activity, and predictive models for quality of soursop tea (Annona muricata L.) during heat pump drying
  111. Characterization and application of Fe1−xCoxFe2O4 nanoparticles in Direct Red 79 adsorption
  112. Torilis arvensis ethanolic extract: Phytochemical analysis, antifungal efficacy, and cytotoxicity properties
  113. Magnetite–poly-1H pyrrole dendritic nanocomposite seeded on poly-1H pyrrole: A promising photocathode for green hydrogen generation from sanitation water without using external sacrificing agent
  114. HPLC and GC–MS analyses of phytochemical compounds in Haloxylon salicornicum extract: Antibacterial and antifungal activity assessment of phytopathogens
  115. Efficient and stable to coking catalysts of ethanol steam reforming comprised of Ni + Ru loaded on MgAl2O4 + LnFe0.7Ni0.3O3 (Ln = La, Pr) nanocomposites prepared via cost-effective procedure with Pluronic P123 copolymer
  116. Nitrogen and boron co-doped carbon dots probe for selectively detecting Hg2+ in water samples and the detection mechanism
  117. Heavy metals in road dust from typical old industrial areas of Wuhan: Seasonal distribution and bioaccessibility-based health risk assessment
  118. Phytochemical profiling and bioactivity evaluation of CBD- and THC-enriched Cannabis sativa extracts: In vitro and in silico investigation of antioxidant and anti-inflammatory effects
  119. Investigating dye adsorption: The role of surface-modified montmorillonite nanoclay in kinetics, isotherms, and thermodynamics
  120. Antimicrobial activity, induction of ROS generation in HepG2 liver cancer cells, and chemical composition of Pterospermum heterophyllum
  121. Study on the performance of nanoparticle-modified PVDF membrane in delaying membrane aging
  122. Impact of cholesterol in encapsulated vitamin E acetate within cocoliposomes
  123. Review Articles
  124. Structural aspects of Pt(η3-X1N1X2)(PL) (X1,2 = O, C, or Se) and Pt(η3-N1N2X1)(PL) (X1 = C, S, or Se) derivatives
  125. Biosurfactants in biocorrosion and corrosion mitigation of metals: An overview
  126. Stimulus-responsive MOF–hydrogel composites: Classification, preparation, characterization, and their advancement in medical treatments
  127. Electrochemical dissolution of titanium under alternating current polarization to obtain its dioxide
  128. Special Issue on Recent Trends in Green Chemistry
  129. Phytochemical screening and antioxidant activity of Vitex agnus-castus L.
  130. Phytochemical study, antioxidant activity, and dermoprotective activity of Chenopodium ambrosioides (L.)
  131. Exploitation of mangliculous marine fungi, Amarenographium solium, for the green synthesis of silver nanoparticles and their activity against multiple drug-resistant bacteria
  132. Study of the phytotoxicity of margines on Pistia stratiotes L.
  133. Special Issue on Advanced Nanomaterials for Energy, Environmental and Biological Applications - Part III
  134. Impact of biogenic zinc oxide nanoparticles on growth, development, and antioxidant system of high protein content crop (Lablab purpureus L.) sweet
  135. Green synthesis, characterization, and application of iron and molybdenum nanoparticles and their composites for enhancing the growth of Solanum lycopersicum
  136. Green synthesis of silver nanoparticles from Olea europaea L. extracted polysaccharides, characterization, and its assessment as an antimicrobial agent against multiple pathogenic microbes
  137. Photocatalytic treatment of organic dyes using metal oxides and nanocomposites: A quantitative study
  138. Antifungal, antioxidant, and photocatalytic activities of greenly synthesized iron oxide nanoparticles
  139. Special Issue on Phytochemical and Pharmacological Scrutinization of Medicinal Plants
  140. Hepatoprotective effects of safranal on acetaminophen-induced hepatotoxicity in rats
  141. Chemical composition and biological properties of Thymus capitatus plants from Algerian high plains: A comparative and analytical study
  142. Chemical composition and bioactivities of the methanol root extracts of Saussurea costus
  143. In vivo protective effects of vitamin C against cyto-genotoxicity induced by Dysphania ambrosioides aqueous extract
  144. Insights about the deleterious impact of a carbamate pesticide on some metabolic immune and antioxidant functions and a focus on the protective ability of a Saharan shrub and its anti-edematous property
  145. A comprehensive review uncovering the anticancerous potential of genkwanin (plant-derived compound) in several human carcinomas
  146. A study to investigate the anticancer potential of carvacrol via targeting Notch signaling in breast cancer
  147. Assessment of anti-diabetic properties of Ziziphus oenopolia (L.) wild edible fruit extract: In vitro and in silico investigations through molecular docking analysis
  148. Optimization of polyphenol extraction, phenolic profile by LC-ESI-MS/MS, antioxidant, anti-enzymatic, and cytotoxic activities of Physalis acutifolia
  149. Phytochemical screening, antioxidant properties, and photo-protective activities of Salvia balansae de Noé ex Coss
  150. Antihyperglycemic, antiglycation, anti-hypercholesteremic, and toxicity evaluation with gas chromatography mass spectrometry profiling for Aloe armatissima leaves
  151. Phyto-fabrication and characterization of gold nanoparticles by using Timur (Zanthoxylum armatum DC) and their effect on wound healing
  152. Does Erodium trifolium (Cav.) Guitt exhibit medicinal properties? Response elements from phytochemical profiling, enzyme-inhibiting, and antioxidant and antimicrobial activities
  153. Integrative in silico evaluation of the antiviral potential of terpenoids and its metal complexes derived from Homalomena aromatica based on main protease of SARS-CoV-2
  154. 6-Methoxyflavone improves anxiety, depression, and memory by increasing monoamines in mice brain: HPLC analysis and in silico studies
  155. Simultaneous extraction and quantification of hydrophilic and lipophilic antioxidants in Solanum lycopersicum L. varieties marketed in Saudi Arabia
  156. Biological evaluation of CH3OH and C2H5OH of Berberis vulgaris for in vivo antileishmanial potential against Leishmania tropica in murine models
Downloaded on 6.12.2025 from https://www.degruyterbrill.com/document/doi/10.1515/chem-2024-0070/html
Scroll to top button