MODULATION OF DICLOFENAC RELEASE FROM A TOTALLY SOLUBLE CONTROLLED-RELEASE DRUG-DELIVERY SYSTEM

A controlled release preparation of diclofenac sodium for oral adminis tration has been developed. The delivery system is designed in such a manner that it provides both zero-order release kinetics or optionally delivers portion of the dose in an instantaneous fashion, followed by linear release. Poly(ethylene oxide) and hydroxypropylmethylcellulose with commonly used excipients together with diclofenac sodium have be en directly compressed into a three-layer matrix system. Results of di ssolution studies show that both biphasic release and zero-order relea se kinetics for up to 24 h are achievable. Mechanism of drug release i s based on both dissolution and swelling/erosion for linear portion of release profile and disintegration/dissolution when burst effect opti on is considered. It may be concluded that drug delivery from this sys tem may reduce some of the side effects associated with enteric-coated NSAIDs and provide extended therapeutic effect.