The objective of this present study was to mask the intensely bitter taste of drotaverine hydrochloride and to formulate orodispersible tablet. Taste masking was done by complexing drotaverine HCl with polymethacrylate polymers (Eudragit E100 and Eudragit RD100) by solvent evaporation technique. The drug: polymer ratio was (1:10) with drug content 40mg. The granules of two optimized drug-polymer complexes (DPCs) were tested for packing and flow properties. These granules were compressed into tablets and evaluated for hardness, friability, drug content, wetting, in vitro disintegration time and in vitro taste in simulated salivary fluid (SSF) of pH 6.2. Their dissolution profiles (i.e. F1 and F2) were compared with commercial formulation (MKT). The optimized formulations were further characterized with Fourier-Transform Infrared Spectroscopy (FTIR) to investigate any interactions between the drug and the added excipients. The granules of the optimized DPCs were free flowing with angle of repose <280. The DPCs tablets (i.e. F1 and F2) had hardness and friability values of ≥ 4kg/cm2 and <0.9% respectively. These tablets disintegrated rapidly (<75sec) with a wetting time of ≤22sec. It also showed rapid drug release in stimulated gastric fluid (SGF) compared with marketed formulation. For instance, the maximum release of drotaverine hydrochloride in F1, F2 and MKT were achieved in 30, 15 and 90mins respectively. Taste evaluation of the DPCs tablets (F1 and F2) in human volunteers revealed considerable taste masking with the degree of bitterness below threshold value. There were also no drug/excipient interactions. This study shows the suitability of polymethacrylate polymers (Eudragit E100 and Eudragit RD100) in masking the bitter taste of orodispersible tablets of drotaverine HCl.
