Multilevel categoric factorial design for optimization of raloxifene hydrochloride solid dispersion in PVP K30 by hot-melt extrusion technology

Abstract

Raloxifene Hydrochloride (RLH) is a selective estrogen receptor modulator (SERM) used for the treatment and prevention of postmenopausal osteoporosis. This Active Pharmaceutical Ingredient (API) belongs to class II biopharmaceutics classification system (BCS) hence it is characterized by solubility-limited bioavailability. The goal of this study is to develop solid dispersion with improved dissolution properties, and enhanced bioavailability via hot-melt extrusion technology. The solid dispersions were made by blending RLH with polyvinylpyrrolidone and polyethylene oxide as polymeric carriers. Design of experiment (DOE) was employed to systematically assess the impact of the formulation variables and their interaction on the drug release profile. The HME conditions were optimized at 165 °C and 150 rpm, ensuring efficient processing. Our findings revealed that Tween 80 and Cremophor RH 40, at a 10 % w/w concentration, served as effective plasticizers for PVP K30. The formulation featuring the highest proportion of PVP K30 (80 % w/w) and Tween 80 as a surfactant exhibited remarkable enhancement of drug release, with over 80 % of the drug dissolving within 30 min and about 100 % within 60 min. The drug has transformed from the crystalline into the amorphous state as confirmed by Differential Scanning Calorimetry (DSC) and Powder X-Ray Diffraction (PXRD), The lead formulation met the USP acceptance criteria for content uniformity, and exhibited a substantial increase in solubility compared to the pure drug across various media.