Design and development of fast dissolving tablets of metronidazole and its in vitro evaluation

The aim of the study was to design and develop a fast dissolving tablets (FDT) containing metronidazole with varying concentration of crospovidone (super disintegrant) by direct compression method with the help of response-surface approach. Experiments were done according to a central composite design to evaluate the effects of two independent variables namely concentration of crospovidone and amount of hydroxy propyl methyl cellulose (HPMC) on the disintegration time and friability of the tablets as responses. Mathematical equation was used for optimization process and a check point batch (CPB) was prepared. Contrast amount of crospovidone and HPMC were used to prepare 10 batches of FDT. In vitro analysis of formulations estimated that the disintegration time of tablets were between 8.0 ± 0.89 and 10.0 ± 1.1 s with increase in the concentration of crospovidone up to 44.9 mg/tab causing the friability to shift from 0.11 to 0.87% (w/w), whereas increase in the concentration of HPMC significantly decreased the % friability (0.11% w/w). Formulation composition that provided the most desired and optimized results was selected as CPB using desirability approach. All the quality control parameters of tablets were investigated as per pharmacopeia. The stability study of CPB was evaluated periodically up to six months. It was concluded that the direct compression method can be used to prepare FDT. On the basis of central composite design, the best composition of formulation can be selected and optimized in a short time of period with minimum trials. However the results also demonstrated the suitability and stability of the formulation.