Abstract

ORODISPERSIBLE SILDENAFIL CITRATE TABLETS: DESIGN AND EVALUATION OF FORMULATION VARIABLES

Rajeev Hiremath *¹, Guru Prasad Mohanta²

ABSTRACT

Orally disintegrating systems have carved a niche amongst the oral drug delivery systems due to the various advantages it offers especially to paediatrics and dysphagia patients.. Sildenafil citrate is a selective inhibitor of phosphodiesterase type 5 enzyme (PDE5) extensively used for the treatment of erectile dysfunction and pulmonary arterial hypertension. It undergoes enzymatic degradation in the gastrointestinal tract, first‐pass metabolism in the liver and posses an disagreeable taste. The objective of present study was to develop orodispersible tablets of sildenafil citrate for the treatment of pulmonary arterial hypertension by overcoming the mentioned drawbacks and to potentially achieve rapid onset of desirable action in a convenient manner. The batches were prepared by direct compression method and the effects of formulation variables such as choice of diluents, binders, superdisintegrants and its concentration on the stability and performance of the dosage form were evaluated. The formulated batches complied with all the unofficial and official tests for tablets. The formulations containing lactose as the diluent showed better disintegration due to its greater aqueous solubility in contrast to microcrystalline cellulose. In vitro disintegration time of 12±2.23 seconds was recorded with the formulation containing Pharmaburst as the orodispersible tablet diluent and superdisintegrant. In- vitro dissolution studies revealed 100% drug release within 5-15minutes for all the formulations. Thus the formulation of orodispersible sildenafil citrate tablet with least steps of process manufacture with rapid disintegration and fast dissolution was achieved. Formulation F5 with Pharmaburst 500 as the excipient (diluents and super disintegrant) with a disintegration time of 12±2.23secs , showing 100 % dissolution within 5 mins and with a very good mouth feel was considered as the best formulation.

Keywords: Orodispersible tablets, Sildenafil citrate, Superdisintegrants, Direct compression.