Effects of various excipients on tizanidine hydrochloride tablets prepared by direct compression

This study was conducted to assess the effects of various excipients in 10 different Tizanidine hydrochloride tablet dosage forms that were prepared by direct compression method (DC). Various excipients are available for DC method; we selected those excipients that are used commonly in tablet manufacturing. The excipients used included lactose anhydrous, di-basic calcium phosphate anhydrous, starch, talc, sodium carboxy methyl cellulose, polyvinyl pyrrolidone (PVP), silicon dioxide (Aerosil), stearic acid, magnesium stearate and microcrystalline cellulose (Avicel). These tablets were then evaluated by performing different pharmacopoeial and non-pharmacopoeial tests (i.e. diameter, hardness, thickness, weight variation, disintegration and assay). It was observed that Formulations B, D and H of Tizanidine hydrochloride gave best results within USP specified limits for the tests employed among all the formulations whereas Formulations F and G showed poor friability, disintegration and dissolution profiles rendering starch in combination of talc and sodium carboxy- methyl cellulose unsuitable for Tizanidine hydrochloride tablet formulations. With the present approach, more studies can be designed using other active ingredients and excipients to get an optimal and cost effective product.