Development of Diclofenac Suspension and Its Stability Study at Different Temperatures

Diclofenac is the most widely used non-steroidal anti-inflammatory drug. However, its oral aqueous formulation is not available in market because of its bitter taste and scratching sensation in throat. This study was conducted to develop a stable suspension formulation of diclofenac. Diclofenac acid suspension was prepared by making some modifications in the previously described method. .For stability study, the suspension was placed in twelve amber colored divided in four sets each consisting of three bottles. The three sets were stored at 4oC, room temperature (22oC±5oC), 40oC and 60oC. The contents of drug in suspension were analyzed immediately after preparation (at zero time), after 2 h, 4 h, 6 hours, 12 h, 24 h, 48 h at 7 days and thereafter, at the end of every week until 13 weeks. To measure drug in sample, diclofenac acid suspension was diluted in absolute ethyl alcohol to make 8ppm of the drug. This solution was filtered and absorbance was measured at 284nm using absolute ethyl alcohol as the blank solution on UV spectrophotometer. The stability was assessed as %age remaining of active content. The highest % remaining drug, 96.03% and 94.93% was found in suspension stored at 4oC and at room temperature, respectively. The shelf life for suspension stored at 4oC, room temperature, 40oC and 60oC was 250 days, 200 days, 66.6 days and 62.5 days, respectively. The physical parameters such as: taste, odor, color, visual appearance, sedimentation volume, Re-dispersion, rheological Properties, and pH were also regularly checked and monitored at the end of every week up to 13 weeks.