Preparation and evaluation of valsartan orodispersible tablets using PVP-K30 and HPMC E3 solid dispersions by the solvent evaporation method

Abstract

Background and purpose:Valsartan (Val), administered for hypertension, exhibits poor water solubility, resulting in low oral bioavailability. This study aimed to enhance the dissolution of Val by preparing orodispersible tablets (ODT) using solid dispersion (SD) technology with PVP and HPMC as hydrophilic carriers.Experimental approach:After preparation of the SDs and physical mixtures of Val: PVP and Val: HPMC at various ratios, the physicochemical characteristics of these mixtures were analyzed. Then, the ODTs were prepared using the best SD sample and evaluated through USP tests.Findings/Results:The saturation solubility of Val: PVP 1:1 and 1:2 at pH 6.8 was notably higher than that of pure Val. The SDs exhibited a superior dissolution rate compared to pure Val and its physical mixtures. Increasing the drug/carrier ratio resulted in a decrease in the percentage of drug in SD, with Val: PVP 1:1 SD showing significantly higher drug loading percentage compared to other formulations. All formulations exhibited entrapment efficiencies above 80. Also, the flow of the SDs was good based on the Hausner ratio.Conclusion and implications:The SDs exhibited more favorable attributes compared to pure Val and its physical mixtures. The research suggests that PVP and HPMC are effective carriers for improving the solubility and dissolution rate of Val. Additionally, mannitol was identified as a beneficial excipient for achieving the desired properties of ODTs. The findings can be applied to other drugs with similar solubility issues, paving the way to improve therapeutic outcomes for patients.