Improvement of Dissolution Characteristics and Bioavailability of Tadalafil by Solid Dispersion Technique Using Water-soluble Polymers

The enhancement of oral bioavailability of poorly water-soluble drugs remains one of the most challenging aspects of drug development. Tadalafil a BCS class II drug is an impotence agent. It is indicated for the treatment of erectile dysfunction and is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type-5 (PDE-5).However, insolubility and poor dissolution of this molecule, delays its rate of absorption and finally the onset of action. Solid dispersion has been successfully utilized as dissolution enhancement technique using water soluble polymers for wide variety of poorly water-soluble drugs. The present study aims at enhancement of dissolution profile of Tadalafil using PVP K30 and PEG 6000 as carriers by solid dispersion technique. Solid dispersion containing Tadalafil was further investigated by drug content, in-vitro drug release, FTIR, DSC, XPRD and SEM analysis. Absence of significant drug‐carrier interaction was confirmed by IR and DSC data. XPRD reveals that crystallinity nature of Tadalafil was decreased. From the study it was concluded that the in-vitro dissolution of Tadalafil can be enhanced by solid dispersion technique.