Development and stability evaluation of enteric coated Diclofenac sodium tablets using Sureteric

This study was aimed to develop a stable enteric coated diclofenac sodium tablets using Sureteic without a subcoating layer. Diclofenac uncoated tablets were developed and manufactured through the non direct compression process. Sureteric white aqueous coating dispersion was used as enteric coating material. Sureteric is a special mixture of Polyvinyl Acetate Phthalate (Phthalavin (R), PVAP), plasticizers and other ingredients in a suitable optimized dry powder formulation. The obtained enteric coated tablets were subjected to disintegration and no sign of cracking was observed when they placed in a hydrochloric solution at pH 1.2, but they were completely disintegrated within 10 minutes when they putted in buffered solution at pH6.8. Dissolution test was also conducted by placing tablets in 0.1 M HCl for 2 hours and then 1 hour in phosphate buffer at pH 6.8. Less than 0.9% of drug was released in the acidic phase and up to 97% in the basic medium. These results show that Sureteric can be successfully used to produce diclofenac sodium enteric coated tablets in order to prevent its release in the stomach and facilitate immediate release of the drug in the duodenum. These findings suggest that aqueous enteric coating with Sureteric system is an easy and economical approach for preparing stable diclofenac sodium enteric coat without the use of a subcoating layer.