LC-MS/MS assay for quantitation of enalapril and enalaprilat in plasma for bioequivalence study in Indian subjects

Preparation of Microsponge Drug Delivery System (MSDDS) Followed by a Scale-Up Approach

In 1987, Won invented the solid-phase porous microsphere (MS), which stores bioactive compounds in many interconnected voids. Spherical particles (5-300 μm), MS, may form clusters of smaller spheres, resulting in many benefits. The current investigation focussed on gel-encased formulation, which can be suitable for dermal usage. First, quasi-emulsion (w/o/w) solvent evaporation was used to prepare 5-fluorouracil (5 FU) MS particles. The final product was characterized (SEM shows porous structure, FTIR and DSC showed drug compatibility with excipients, and gel formulation is shear-thinning) and further scaled up using the 8-fold method. Furthermore, CCD (Central Composite Design) was implemented to obtain the optimized results. After optimizing the conditions, including the polymer (600 mg, ethyl cellulose (EC), eudragit RS 100 (ERS)), stirring speed (1197 rpm), and surfactant concentration (2% w/v), we achieved the following results: optimal yield (63%), mean particle size (152 µm), drug entrapment efficiency (76%), and cumulative drug release (74.24% within 8 h). These findings are promising for industrial applications and align with the objectives outlined in UN Sustainable Development Goals 3, 9, and 17, as well as the goals of the G20 initiative.

Low-volume LC-MS/MS method for the pharmacokinetic investigation of carvedilol, enalapril and their metabolites in whole blood and plasma: Application to a paediatric clinical trial

Evidence-based pharmacotherapy with carvedilol and enalapril in children suffering from heart failure is insufficient owing to limited pharmacokinetic data. Although a few data sets regarding enalapril, its metabolite enalaprilat and carvedilol in children have been published, pharmacokinetic data on carvedilol metabolites are missing. However, for both drug substances, their active metabolites contribute substantially to drug efficacy. As data can hardly be derived from adults owing to the unknown impacts of enzymatic maturation and ontogeny during childhood, customised assays are important to facilitate paediatric evidence-based pharmacotherapy. Considering ethical paediatric constraints, a low-volume liquid chromatography coupled to mass spectrometry (LC-MS/MS) assay was developed using whole blood or plasma for the quantification of enalapril, enalaprilat, carvedilol, O-desmethyl carvedilol, 4- and 5-hydroxyphenyl carvedilol as well as 3- and 8-hydroxy carvedilol. To facilitate broader applications in adults, the elderly and children, a wide calibration range-between 0.024/0.049 and 50.000 ng/ml-was achieved with good linearity (r ≥ 0.995 for all analytes). In compliance with international bioanalytical guidelines, accuracy, precision, sensitivity and internal standard normalised matrix effects were further successfully validated with the exception of those for 3-hydroxy carvedilol, which was therefore assessed semi-quantitatively. Distinct haematocrits did not impact matrix effects or recoveries when analysing whole blood. Blood-to-plasma ratios were determined for all analytes to form the basis for pharmacokinetic modelling. Finally, incurred sample reanalysis of paediatric samples confirmed the reproducibility of the developed low-volume LC-MS/MS method during study sample analysis. The assay facilitates the reliable generation of important data and contributes towards a safe drug therapy in children.

Ultrasonication-assisted extraction of a phytomelatonin-rich, erucic acid-lean nutraceutical supplement from mustard seeds: an antioxidant synergy in the extract by reductionism

Phytomelatonin-rich (194.02 ± 2.45-205.80 ± 1.67 ng/g of dry mustard seeds) and erucic acid-lean (below 2%) extracts from an oilseed crop, (yellow and black mustard seeds) have been successfully obtained by ultrasonication-assisted-extraction in ethanol-water. Fourier-transform infrared spectroscopy and liquid chromatography-mass spectrum analyses have confirmed the presence of phytomelatonin along with tocopherol, ascorbic acid, limonene and linalool in the extract. Field emission scanning electron micrographs confirmed the cavitational effects of sonication on mustard seed matrices. Electron paramagnetic resonance spectroscopy established the strong antioxidant activities (72.25-75.49%) of the extracts foregoing erroneous spectrophotometric result of pan assay interference compounds. A synergistic effect value of 1.13 (greater than unity) confirmed synergistic co-existence of the antioxidants in the extract. This study interestingly revealed that an antioxidant synergy could be obtained by classical reductionism. Acute oral toxicity of the extracts were found to be greater than 5000 mg/kg body weight of rats. The extracts are perfectly safe to be utilized as antioxidative food supplements.

LC-MS/MS determination of 4-hydroxynimesulide, an active metabolite of nimesulide and application to bioequivalence study in Indian subjects

A simple and highly sensitive bioanalytical method was developed and validated for simultaneous quantification of nimesulide (NSD) and its active metabolite 4-hydroxy-nimesulide (M1) in human plasma by liquid chromatography-tandem mass spectrometer (LC-MS/MS) and applied in a bioequivalence study performed on Indian subjects. The bioanalytical method was carried out by LC-MS/MS with celecoxib (CXB) as an internal standard (IS) using liquid-liquid extraction technique. The chromatographic separation was performed on a reversed-phase Agilent eclipse plus C18 (75 mm × 4.6 mm, particle size 3.5 µm) column with a mobile phase of acetronitrile and water containing 5 mM ammonium formate (9:1, v/v). Method validation and clinical sample were analysed as per USFDA and EMA guidelines and results met the acceptance criteria. The lower limit of quantitation of NSD and M1 was found 10 ng/mL with a large linearity range from 10 to 6000 ng/mL for both NSD and M1 using only 100 µL of plasma and reported no matrix effect. The multiple reaction monitoring transitions of m/z 307.20 → 229.20, m/z 323.00 → 245.00 and m/z 380.20 → 316.20 were used to measure NSD, M1 and CXB (IS), respectively. The assay method was successfully applied for the simultaneous quantification of both NSD and M1 in plasma samples after oral administration of nimesulide 100 mg tablet in healthy human subjects.

Consortia of bioactives in supercritical carbon dioxide extracts of mustard and small cardamom seeds lower serum cholesterol levels in rats: new leads for hypocholesterolaemic supplements from spices

Melatonin-rich and 1,8-cineole-rich extracts have been successfully obtained from yellow mustard (YM) and small cardamom (SC) seeds, respectively, employing green technology of supercritical CO₂ (SC-CO₂) extraction. Chemical profiling confirmed the presence of melatonin and 1,8-cineole and co-extractants in the respective extracts. Electron paramagnetic resonance spectroscopy attested strong antioxidant activities of the extracts foregoing pan-assay interference compounds involved in spectroscopic analysis. These extracts also exhibited synergistic efficacies greater than unity confirming antioxidant synergy among the co-extracted bioactives therein. To ascertain hypocholesterolaemic efficacies, these extracts were co-administered orally with Triton X (at the pre-optimised dose of 175 mg/kg body weight (BW)) to Wistar albino rats at doses of 550, 175 and 55 mg/kg BW. Serum total cholesterol levels in the rats were monitored on days 3, 7, 15 and 21. On day 21, total cholesterol level reduced appreciably by 49·44 % in rats treated with YM seed extract and by 48·95 % in rats treated with SC seed extract, comparable with atorvastatin-administered rats (51·09 %). Either extract demonstrated inhibitory effects on hepatic 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase activity. A molecular docking exercise identified specific compounds in the extracts which possessed binding affinities comparable with therapeutically used HMG-CoA reductase inhibitors. In silico and in vivo studies concertedly concluded that the consortium of bioactive components in the extracts cannot be considered as invalid metabolic panaceas and therefore these 'green' extracts could be safely subjected to clinical studies as preventive biotherapeutics for hypercholesterolaemia. These extracts could be consumed per se as hypocholesterolaemic supplements or could be ingredients of new spice-based therapeutic foods.

Simultaneous Determination of Rivaroxaban and Enalapril in Rat Plasma by UPLC-MS/MS and Its Application to A Pharmacokinetic Interaction Study

BACKGROUND AND OBJECTIVES

There have been no animal experiments and clinical studies on the pharmacokinetic interaction between rivaroxaban and enalapril. To investigate whether a potential pharmacokinetic interaction is present between rivaroxaban and enalapril, a rapid and sensitive Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to determine the concentration of rivaroxaban and enalapril in rat plasma and was then applied to a pharmacokinetic interaction study.

METHODS

The analytes were separated on an Acquity UPLC BEH C18 chromatography column (2.1 × 50 mm, 1.7 μm) with acetonitrile and 0.1% formic acid as the mobile phase with gradient elution. The mass spectrometer was operated in multiple reaction monitoring mode to monitor the precursor-to-product ion transitions of 436.1 → 145.1 m/z for rivaroxaban, 377.3 → 234.2 m/z for enalapril and 285.2 → 193.1 m/z for diazepam (IS).

RESULTS

The method was validated over the concentration range of 1.0-200 ng/mL for rivaroxaban and 0.5-100 ng/mL for enalapril. The intra- and inter-day precision and accuracy of the quality control (QC) samples exhibited relative standard deviations (RSD) < 9.4% and the accuracy values ranged from - 8.3 to 9.6%. After co-administration of rivaroxaban and enalapril, the maximum plasma concentration (C_max) and area under the systemic drug concentration-time curve from time 0 to infinity (AUC_0-∞) of rivaroxaban were significantly increased by 19.6% (p < 0.05) and 21.3% (p < 0.05), respectively. On the contrary, the plasma clearance rate (CL/F) of rivaroxaban and enalapril was significantly decreased by 17.8% (p < 0.05) and 23.8% (p < 0.05), respectively.

CONCLUSIONS

The UPLC-MS/MS method was successfully applied to simultaneous determination of rivaroxaban and enalapril in rat plasma and applied to study the pharmacokinetic interaction between rivaroxaban and enalapril. The co-administration of rivaroxaban and enalapril resulted in a significant drug interaction in rats.