Influence of Surfactant-Based Polymer as Micellar Carrier on Dissolution Properties and Oral Bioavailability of Abiraterone Acetate

Abiraterone acetate is a novel antiandrogen drug indicated for prostate cancer. However, it suffers from low bioavailability owing to poor dissolution properties. The present work was aimed to develop abiraterone acetate nano-micelles to improve its dissolution properties and oral bioavailability. Film hydration method was employed to fabricate the abiraterone acetate nano-micelles. Impact of various variables on the formulation of abiraterone acetate nano-micelles were studied in the preliminary trials. Central composite design was employed with independent variables identified in the preliminary studies, viz. X 1 - Stirring speed and X 2 - Stirring time. Drug release studies were carried out to check the change in dissolution properties of abiraterone acetate nano-micelles as compared to pure drug. In vivo animal studies were carried out to check the pharmacokinetic parameters. Drug physical alterations caused by nano-micellization were analyzed by solid state characterization (FTIR, DSC, XRD and SEM) experiments. Accelerated stability studies for six months was carried out on the optimized formulation. Results demonstrated influence of various process variables on particle size of abiraterone acetate nano-micelles. In vitro dissolution showed an increase in drug release rate from nano-micelles as compared to pure drug dispersion. Abiraterone acetate nano-micelle’s oral bioavailability significantly improved by 32-fold. Accelerated stability studies of the optimized formulation suggested stability of the nano-micelles for at least six-month time. Thus, dissolution properties and oral bioavailability of abiraterone acetate was enhanced by formulating nano-micelles.