Comparison of Clobetasol Propionate Generics Using Simplified In vitro Bioequivalence Method for Topical Drug Products.

Background: The aim of this paper is to evaluate a simple in vitro skin penetration experiment in which the drug is extracted from the whole skin piece as a test valid for formulation screening and optimization during development process, equivalence assessment during quality control or postapproval after changes to the product.

Methods: Twelve clobetasol propionate (CP) formulations (six creams and six ointments, being five generics and one reference from each formulation type) from the local market were used as a model to challenge the evaluated methodology in comparison to in vitro skin penetration following tape-stripping for drug extraction. To support the results, physicochemical tests for pH, viscosity, density and assay, as well as in vitro release were performed.

An improved LC-MS/MS method for quantitation of indapamide in whole blood: application for a bioequivalence study.

An improved LC-MS/MS method for the quantitation of indapamide in human whole blood was developed and validated. Indapamide-d3 was used as internal standard (IS) and liquid-liquid extraction was employed for sample preparation. LC separation was performed on Synergi Polar RP-column (50 × 4.

Determination of 3-α-hydroxytibolone in human plasma by LC-MS/MS: application for a pharmacokinetic study after administration of a tibolone formulation.

A new method was developed for the quantitation of 3-α-hydroxy tibolone, in human plasma, after oral administration of a tablet formulation containing tibolone (2.5 mg). 3-α-Hydroxy tibolone was extracted by a liquid-liquid procedure, using cyproterone acetate as internal standard and chlorobutane as extraction solvent.

Determination of captopril in human plasma, using solid phase extraction and high-performance liquid chromatography, coupled to mass spectrometry: application to bioequivalence study.

A specific high performance liquid chromatography-mass spectrometric (LC-MS/MS) assay was developed for the determination of captopryl in plasma. The retention time was 1.45 and 1.