Chromatographic method for the simultaneous quantification of dapsone and clofazimine in nanoformulations

Abstract

The low bioavailability and nonspecific distribution of dapsone and clofazimine, commonly applied in combination for the treatment of leprosy, can produce toxic effects. Nanotechnological approaches enhance the delivery of these drugs. Therefore, a high-performance liquid chromatography method was developed for the simultaneous determination of dapsone and clofazimine loaded in nanoformulations for quality control purposes. Chromatographic separation was achieved on a reversed-phase Kinetex core-shell C18 column, followed by spectrophotometric detection at 280 nm. Considering the different physicochemical properties of dapsone and clofazimine, elution was performed in gradient mode using an aqueous acetate buffer (50 mmol/L, pH 4.8) and an increasing acetonitrile content from 27 to 63% v/v at a flow rate of 1.0 mL/min with retention times of 6.2 and 14.0 min, respectively. The method was validated according to the European Medicines Agency guideline and it was found to be specific, accurate (99.6-114.0%), and precise for intra- (RSD ≤ 1.8%) and interday assays (RSD ≤ 12.5%). Both drugs showed stability after 24 h at room temperature and over three freeze-thaw cycles with recoveries ≥86.2%. Low temperature (4°C) in the autosampler caused the precipitation of clofazimine and must be avoided. The validated method was successfully applied in the quantification of both drugs in nanoformulations.

Stability indicating liquid chromatographic method for simultaneous quantification of betamethasone valerate and tazarotene in in vitro and ex vivo studies of complex nanoformulation

“…As a part of combination therapy, betamethasone valerate and tazarotene are preferred to provide improved therapeutic efficacy with lesser side effects . For such combination formulation analysis, there is current need of simultaneous HPLC analysis method which can be utilized to estimate simultaneously betamethasone valerate and tazarotene in the routine analysis of preformulation samples, in vitro drug release samples, ex vivo studies of conventional and complex nanoformulations . Simultaneous method development is advantageous to analyze multiple drugs in a single formulation in a short time which resulted in being cost‐effective for academic and industrial research .…”