Quality By Design Approach For Development Of Amorphous Solid Dispersions Of Efavirenz By Melt-Quench Technique

Abstract

Melt-quench method is a novel and an evolving technique to develop amorphous solid dispersions (ASDs) of crystalline compounds to improve their solubility. Efavirenz is a crystalline compound and is practically insoluble in water so that it suffers dissolution limited bioavailability. The major objective of this work was to optimize carrier, plasticizer and cooling temperature as the independent factors used in melt-quench method for preparing Efavirenz ASDs (EASDs) to have maximum solubility and stability which were taken as the responses. Box-Behnken design (BBD) under response surface methodology was employed as the experimental design to develop EASDs. The prepared EASDs were characterized by differential scanning calorimetry (DSC) and X-ray diffraction (X-RD) analysis to investigate the physical state of EFV and the stability of the EASDs upon storage. Solubility was also checked for all the EASDs. The effect of the factors on the responses were analysed found to be significant by analysis of variance (ANOVA) at p < 0.05. The DSC and X-RD results indicated that EFV was successfully converted into amorphous form by the applied method. Further, DSC and solubility studies also inferred that slow cooling with high concentrations of the carrier and plasticizer provided maximum stability of these ASDs upon storage by reducing recrystallization. The graphical optimization was performed and inferred that the EASDs prepared at 50% w/w of Soluplus as the carrier, 15% w/w of Poloxamer 188 as the plasticizer with -1.92^oC as the cooling temperature in melt-quench method provided EASDs with maximum solubility and stability.