Application of 3<sup>2</sup> Factorial Design in Formulation and Evaluation of Olmesartan Medoxomil Floating Microsponges

Abstract

The goal of the research was to formulate floating microsponges of Olmesartan medoxomil by 3² factorial design to enhance bioavailability in the gastric region. The quasi-emulsion solvent diffusion method was used to prepare gastroretentive floating microsponges. In this study, the concentration of Eudragit L-100 (X₁) and the concentration of polyvinyl alcohol (PVA) (X₂) were chosen as independent factors at three distinct levels using Design-Expert® software (trial version 13.1.0, Stat-Ease). The dependent variables chosen were the % Buoyancy (Y₁) and % cumulative drug release (Y₂). The percent yield, particle size, bulk density, % buoyancy, % entrapment efficiency, in vitro drug release, the kinetics of drug release, variation of the model, Fourier Transform Infrared Spectroscopy (FTIR) studies, and stability studies for the optimized formulation were conducted. From the design expert, the optimized formula was found to be OLM-MSG7. The magnitude of the coefficient of both X₁ and X₂ showed a positive effect on the buoyancy of the floating microsponges. As the concentration of eudragit L-100, the buoyancy of the microsponges increased. The reason for the buoyancy due to the high concentration of eudragit L-100 may be attributed to the low density of the polymer. However, an antagonistic linear effect of PVA was observed. X₁ and X₂ i.e., polymer concentration and PVA had a positive effect on % CDR of microsponges which indicates that the higher amount of eudragit L-100 contributes to an increase in % CDR. FTIR studies show there is no chemical interaction between the drug and the polymer in the formulation.