Effect of ethylcellulose grade and sealant treatments on the production and in vitro release of microencapsulated sodium salicylate

Abstract

Sodium salicylate was microencapsulated with ethylcellulose 100 cp by polymer deposition from cyclohexane by temperature change to give a finer product, with slower drug release, than that obtained with 10 cp grade of ethylcellulose. Scanning electron microscope and polymer disc swelling studies confirmed that larger microcapsules after drug release ruptured into smaller particles with swollen surfaces containing pores. Treatment of microcapsules with paraffin wax solution retarded release of core material, the release being affected by the percentage of sealant used and the particle size of the product. The mechanism of release from the sealed microcapsules was complex involving mainly diffusion, but polymer erosion and drug binding were also involved. Other sealant materials were less effective in retarding dissolution.

Effect of Polyisobutylene on Ethylcellulose-Walled Microcapsules: Wall Structure and Thickness of Salicylamide and Theophylline Microcapsules

“…Deasy et al (9) obtained a product with surface properties closely similar to the aggregates shown in Fig. 2.…”

Factorial design-based optimization of the formulation of isosorbide-5-mononitrate microcapsules

“…The reason ethylcellulose is selected as the wall material is as follows: it is used in tablet and suspension formulations, it is the most used wall material in tablet formulations and it has no side-effects (Deasy et al 1980, Benita and Donbrow 1982, Alpar and Walters 1982, Rowe 1985.…”

Aliphatic Polyesters and Cellulose-Based Polymers for Controlled Release Applications

“…The effect of ethylcellulose grade and sealant treatments on the production and release of microencapsulated sodium salicylate was studied by Deasy et al [44]. They compared ethylcellulose 100 cp with EC 10 cp in coacervation from cyclohexane with temperature change.…”