Formulation and in vitro characterization of novel sildenafil citrate-loaded polyvinyl alcohol-polyethylene glycol graft copolymer-based orally dissolving films

Abstract

This work was aimed to develop novel sildenafil citrate (SC)-loaded polyvinyl alcohol (PVA)-polyethylene glycol (PEG) graft copolymer (Kollicoat(®) IR)-based orally dissolving films (ODFs) using a solvent casting method. Formulation factors such as plasticizers and disintegrants were optimized on the basis of characteristics of blank ODFs. The SC-loaded ODF with a loading capacity up to 6.25mg in an area of 6 cm(2) was prepared and evaluated in terms of mechanical properties, disintegration time and dissolution rate. The physicochemical properties of drug-loaded ODF were also investigated using the scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). The blank ODF composed of Kollicoat(®) IR, sodium alginate (ALG-Na) and glycerol (10:2:1.5, w/w) had a remarkably short disintegration time of about 20s. The SC-loaded ODF showed a delayed disintegration time (about 25s), but exhibited improved mechanical properties when compared to the blank ODF. SC was homogeneously dispersed throughout the ODF and the crystalline form of drug had been partly changed, existing strong hydrogen bonding between the drug and carriers. The Kollicoat(®) IR/ALG-Na based ODFs containing SC might be an alternative to conventional tablet for the treatment of male erectile dysfunction.

Keywords: Formulation; In vitro characterization; Orally dissolving film; Polyvinyl alcohol-polyethylene glycol graft copolymer; Sildenafil citrate.