Bioavailability Enhancement of Poorly Aqueous Soluble Atorvastatin Calcium by Solid Dispersion Technique Using a Modified Natural Polymer as a Hydrophilic Carrier

Purpose The goal of this study was to improve the solubility and bioavailability of poorly water-soluble atorvastatin calcium (ATC) by solid dispersion technique using natural polymer as a hydrophilic carrier. ATC is an anti-hyperlipidemic agent with low bioavailability due to its inability to dissolve in water. As a result, an effort has been undertaken to improve ATC’s oral bioavailability by making it more water-soluble using the solid dispersion approach. Methods Solid dispersions (SD) were prepared by using modified Samanea saman seed gum (MSSSG) as a natural hydrophilic carrier. Amongst various available methods, solvent evaporation method was selected to prepare solid dispersions. The chemical interaction between ATC and modified hydrophilic carrier was evaluated by FTIR spectroscopy. Results The result of the solubility study of ATC from solid dispersion found greater solubility of ATC compared to pure drug. The outcomes of an in vitro drug release study show higher cumulative drug release at 120 min, that is 96.95% of ATC from prepared solid dispersions in comparison to pure ATC, which was only 65.36%. The prepared solid dispersions were evaluated by DSC, XRD, and SEM studies. DSC and XRD study findings revealed that the crystalline drug was converted into an amorphous state. Pharmacokinetic study in rats showed approximately 1.68- and 2.3-fold increments in C max and AUC respectively in case of solid dispersion as compared to plain ATC. Conclusion In conclusion, MSSSG could be a promising carrier to improve the solubility, dissolution rate, and bioavailability of poorly water-soluble ATC. Graphical Abstract