A NOVEL CORE-COAT CHRONOTHERAPEUTIC TECHNIQUE FOR EFFECTIVE DELIVERY OF ANTIHYPERTENSIVE DRUG

Abstract

Objective: The objective of the work was to formulate coated microbeads using core-coat technique for chronotherapeutic delivery of Carvedilol (cd).Methods: Sodium alginate microbeads containing cd was formulated by ionic gelation method using calcium chloride as a gelling agent. Microbeads were then coated with acrylcoat L 100 (acL 100), acrylcoat S 100 (acS 100), ethyl cellulose (EC), and acrylcoat E30 D (acE 30D) in different ratio. Formulated batches were evaluated using FTIR, particle size measurement, percent entrapment efficiency, micrometric properties, swelling studies, loose surface crystal studies, percentage moisture loss. The formulations were then subjected to in vitro dissolution studies. Cumulative release data was then subjected to different dissolution models reported in the literature.Results: Formulated batches of microbeads were within acceptable particle size range with good to fair flow properties. Entrapment efficiency was in the range of 64% to 99.52%. Loose surface crystal study revealed successful drug entrapment within a range of 2.11 to 9.93%. Swelling studies revealed maximum swelling in alkaline phosphate buffer pH 7.4 solution and percentage moisture loss was within 0.24% to 7.55%. SEM showed microbeads to be spherical in nature and FTIR study exhibited compatibility among the drug and polymer. In vitro release study was carried out for first 3 h in 0.1N HCl and subsequently for 7 h in phosphate buffer solution pH 7.4. Formulation code AC3, AC4, LA4 and LA6 were found in line with our objective of chronotherapeutic drug delivery.Conclusion: Sodium alginate beads loaded with cd and coated with different ratios of coating solutions were successfully formulated and evaluated to optimize the best possible combinations of the coat-core ratio for chronotherapeutic delivery.