Application of hydrophilic polymers for the preparation of tadalafil solid dispersions: micromeritics properties, release and erectile dysfunction studies in male rats

The objective of the present study was to improve the dissolution rate and aphrodisiac activity of tadalafil by using hydrophilic polymers. Solid dispersions were prepared by solvent evaporation-Rota evaporator using Koliphore 188, Kollidon^® VA64, and Kollidon^® 30 polymers in a 1:1 ratio. Prepared tadalafil-solid dispersions (SDs) evaluated for yield, drug content, micromeritics properties, physicochemical characterizations, and aphrodisiac activity assessment. The optimized SDs TK188 showed size (2.175 ± 0.24 µm), percentage of content (98.89 ± 1.23%), yield (87.27 ± 3.13%), bulk density (0.496 ± 0.005 g/cm3), true density (0.646 ± 0.003 g/cm3), Carr's index (23.25 ± 0.81), Hausner ratio (1.303 ± 0.003) and angle of repose (<25°). FTIR spectrums revealed tadalafil doesn't chemically interact with used polymers. XRD and DSC analysis represents TK188 SDs were in the amorphous state. Drug release was 97.17 ± 2.43% for TK188, whereas it was 32.76 ± 2.65% for pure drug at the end of 2 h with 2.96-fold increase in dissolution and followed release kinetics of Korsmeyer Peppa's model. MDT and DE were noted to be 17.48 minutes and 84.53%, respectively. Furthermore, TK188 SDs showed relative improvement in the sexual behavior of the male rats. Thus the developed SDs TK188 could be potential tadalafil carriers for the treatment of erectile dysfunction.