Validated RP-HPLC method for quantification of felodipine in rabbit plasma: Application in a bioequivalence study

Micellar-Emphasised simultaneous determination of ivabradine hydrochloride and felodipine using synchronous spectrofluorimetry

Sensitive and green micellar spectrofluorimetric approach was applied for the simultaneous estimation of ivabradine hydrochloride (IVB) and felodipine (FLD) in ng/mL concentration range. The approach depended on measuring the first derivative synchronous peak amplitude (¹ D) of both drugs at ∆λ= 60 nm in tween-80 micellar system. The method was rectilinear alongside the concentration range (0.02-0.4) μg/mL and (0.05-1.0) μg/mL at 269.5 nm and 378.5 nm for of IVB and FLD, respectively. The proposed method was validated by following ICH guidelines. The method was successfully applied without interference for laboratory-prepared synthetic mixtures, single pharmaceutical preparation and within spiked biological fluids with acceptable percent recoveries. Comparing the performance of the suggested method with the comparison methods, showed no discrepancy. The method ecofriendly properties were evaluated by 3 different tools confirming an excellent green method.

Meloxicam quantification in rabbit plasma by RP-HPLC: optimization and application to pharmacokinetic study

Background

The goal of the proposed study was to validate a rapid, simple, an accurate, robust, and sensitive bioanalytical method for quantifying Meloxicam and Lornoxicam (as internal standard) in rabbit plasma.

Result

Limit of detection and limit of quantification for Meloxicam were found to be 0.0081 and 0.1035 μg mL−1, respectively. The bioanalysis was continued according to standard guidelines and successfully used for bioavailability studies of meloxicam after single dose administration of pure drug and the formulation in rabbit plasma. Finally, obtained results proved its simplicity and an efficiency to be applied for the therapeutic drug monitoring and bioequivalence studies.

Conclusion

Therefore, the set RP-HPLC bioanalysis is simple, convenient, and acceptable to analyze meloxicam in bulk and pharmaceutical formulations in rabbit plasma.

Graphical abstract

Validated RP-HPLC method for quantification of doxazosin in human plasma: Application in a bioequivalence study

OBJECTIVES

The aim of the present study was to validate a simple, sensitive, HPLC method of analysis of doxazosin in human plasma with fluorescence detection.

METHODS

The validated method employed one-step direct protein precipitation with acetonitrile. Chromatographic separation was attained using a reverse-phase 250mm×4.6mm 5μ Hypersil® BDS C 18 column and the mobile phase consisted of 10mm sodium dihydrogen phosphate dihydrate (pH=3.0) and acetonitrile at a ratio of (65:35 v/v). The method was evaluated in terms of linearity, precision, accuracy, selectivity and stability as per standard guidelines. The total run time was about 4.5min which make this method suitable for high throughput analyses. This method was applied to the bioequivalence study of two doxazosin tablets in healthy human volunteers.

RESULTS

Good linear response was achieved over the range of 5.0-200ng/mL. The observed within- and between-day assay precision ranged from 0.64% to 14.73%; accuracy varied between 94.11% and 105%. The 90% confidence intervals for the ratio Cmax, and AUC 0-∞ of the test product over those of reference were within the acceptable range (0.8-1.25) for bioequivalence.

CONCLUSION

The developed method was simple and could be applied to therapeutic drug monitoring of doxazosin.