Purpose: The aim of this study was to improve the dissolution of eprosartan mesylate (ESM) using solid dispersions (SDs). Various compositions of polyethylene glycol polymers (PEG) were tested in attempt to improve ESM bioavailability after oral administration. Methods: ESM solid dispersions (SDs) were prepared (by solvent method) using mixtures of PEG 3350 or PEG 6000 at various drug-polymer ratios (1:1), (1:2), (1:3), (1:4), (1:5) w/w with or without Tween 80 added at 0.1% of drug weight. Physical mixtures (PMs) of drug and carriers were also prepared at same ratios and used. Drug solid dispersions and physical mixtures were characterized in terms of drug content and drug dissolution using USP II dissolution apparatus. Drug dissolution enhancement ratio (ER) from SD in comparison to the crude drug was calculated. Drug- polymer interactions were also evaluated using Differential Scanning Calorimetry (DSC) and Fourier transform infrared (FT-IR). Results: The in vitro dissolution studies showed that SDs prepared using both polymers produced a remarkable improvement in drug dissolution which reached around 32% in comparison to the crude drug (p<0.05). The dissolution enhancement ratio was polymer-concentration dependent but up to a certain concentration and this varied according to the used polymer. Adding Tween 80 to the SD did not show further dissolution enhancement but reduced the required amount of the polymer to get the same dissolution enhancement. The DSC and FT-IR studies indicated that using SD resulted in transformation of drug from crystalline to amorphous form. Conclusion: This study indicated that SD prepared by using both polymers i.e. PEG 3350 and PEG 6000 improved the in vitro dissolution of ESM remarkably which which could result in improving in improving the drug bioavailability, but further in vivo studies are required (Graphical Abstract).
- Eprosartan mesylate; Solid dispersions; Solvent method; PEG 3350; PEG 6000; Dissolution test