Author(s): Gandla Swetha
The objective of this research work was to prepare a chrono-modulated drug delivery system to meet chronopharmacological needs of arthritis.In this study naproxen was selected as a model drug.Core in cup tablets is a novel oral pulsatile release drug delivery system based on a core-in-cup dry coated tablet, where the core tablet surrounded on the bottom and circumference wall with inactive material. The system consists of three different parts, a core tablet containing active ingredient, an impermeable outer shell and a top layer-barrier of a soluble polymer. The impermeable coating cup consisted of ethyl cellulose and the top cover layer of hydrophilic swellable material. The system releases the drug after certain period of lag time generally due to the erosion of top cover layer. To meet this objective an initial lag phase for 3-5 hrs and later a rapid release phase was considered. The lag phase in release (2hr) was achieved by coating EC core tablets with release retarding polymers HPMCK4.