press coated tablets.

The objective of present investigation was to prepare a chrono-modulated drug delivery system for Naproxen sodium to meet chrono pharmacological needs of Arthritis. Press coated tablets is a novel oral pulsatile release drug delivery system in which  the drug is released after certain period of lag time generally due to the erosion of barrier layers. Tablets were prepared by direct compression method. The core tablet was formulated using super-disintegrants like sodium starch glycolate, crosspovidone and crosscarmellose sodium. Whereas, the barrier layer contains polymers like carrageenan gum (Viscarin GP-209), xanthan gum in different concentrations and lactose anhydrous as channeling agent for maintaining lag time. The drug-excipient compatibility was confirmed by using FTIR, predicted that there was no chemical interactions between the drug and excipients. The tablets prepared were evaluated for micromeritic properties. In-vitro drug release studies were carried out using pH 1.2 buffer for initial 2hrs and in pH 7.4 phosphate buffer for remaining 10hrs. All the formulations followed first order release kinetics. From the obtained results it was found that the F9 formulation of immediate release core tablets (10% of Crosspovidone) showed optimized in vitro disintegration time and wetting time respectively. In case of press-coated tablets PCT 8 formulation with hydrophilic polymers 19.2% carrageenan gum, 19.2% xanthan gum and 7.69% lactose anhydrous as channeling agent has shown 6hrs of lag time is considered as optimum formulation and is successful in resisting different RPM pressures for designing into pulsatile delivery for treatment of Arthritis.