COMPARATIVE EVALUATION OF DIFFERENT BRANDS OF ENTERIC-COATED DICLOFENAC SODIUM TABLETS

Diclofenac sodium is a non-steroidal anti-inflammatory drug with wide use in the treatment of rheumatic diseases. Enteric-coated tablet form of this drug has been developed to prevent the gastric irritation problem encountered with its use and to improve its efficacy. The enteric film coat resists solution in gastric fluid and disintegrates and releases the medication in the intestines. Many brands of enteric coated tablets of diclofenac sodium are manufactured and sold in the market. However, there is a real concern that counterfeited drugs and drugs with poor pharmaceutical quality could enter the Libyan market. In this study, the physicochemical quality of four brands of diclofenac sodium 50 mg enteric-coated tablets was assessed and compared in terms of visual inspected characters, diameter, thickness, weight uniformity, hardness, friability, disintegration time, dissolution, and drug content. The brands compared were Voltarène^TM (brand A), Diclofenac Normon^TM(Brand B), Neoflam^TM (brand C), and Divon^TM (brand D). As expected, brand A showed acceptable results considering it to be the original brand name drug. Brands B and D also exhibited comparable results to that obtained with brand A. Therefore, it is expected for these brands to behave similarly in vivo and can be efficiently interchanged. Brand C exhibited lower solidity, inability to avoid disintegration in acidic medium, and an earlier release profile. Consequently, tablets are unable to maintain their integrity in the stomach leading to gastric irritation and poor bioavailability.