Effect of cellulose acetate phthalate and polyethylene glycol on physical properties and release of theophylline from microcapsules

Abstract

The present study describes the development of theophylline microcapsules by a non-solvent addition method and the effect of plasticizer addition on microencapsulation. The release was studied in distilled water and the data were analysed by various mathematical models for determining the mechanism of release. Prepared microcapsules were found to be spherical, free flowing and having more than 80% entrapped drug. The polymer -cellulose acetate phthalate and plasticizer -polyethylene glycol was considered to be affecting the properties of microcapsules including drug release (time for 50% drug release, T 50 ). The formulation with the highest proportion of polymer and without plasticizer (F3) showed the slowest release with T 50 = 4.3 h, while the formulation with lower proportion of polymer and 20% (w/w) plasticizer (F13 &14) showed the fastest release of drug with T 50 values of 1.2 h and 1.3 h, respectively. The drug release from most of the formulations was found to be following Higuchi model. It is concluded from the results of the present study that cellulose acetate phthalate significantly affects the sustained release of the drug in water, whereas the addition of polyethylene glycol slightly enhances the drug release.Uniterms: Theophylline/microcapsules. Microencapsulation. Cellulose acetate phthalate. Polyethylene glycol. Microcapsules/mechanism of release. Drugs/release. O presente estudo descreve o desenvolvimento de microcápsulas de teofilina pelo método sem adição de solvente e o efeito da adição de plastificante na microencapsulação. A liberação foi estudada em água destilada e os dados foram analisados por vários modelos matemáticos para determinação do mecanismo de liberação. As microcápsulas preparadas mostraram-se esféricas, livres de corrente e com mais de 80% de fármaco encapsulado. O polímero -ftalato de acetato de celulose e o plastificante -polietileno glicol -afetaram as propriedades das microcápsulas, incluindo a liberação do fármaco (tempo para liberação de 50% do fármaco, T 50 ). A formulação com a maior proporção de polímero e sem plastificante (F3) se mostrou como a de liberação mais lenta, com T 50 = 4,3 h, enquanto as formulações com menor proporção de polímero e 20% de plastificante (m/m) (F13 &14) apresentaram a liberação mais rápida do fármaco, com T 50 de 1,2 h e 1,3 h, respectivamente. A liberação do fármaco para a maioria das formulações seguiu o modelo de Higuchi. Concluiu-se, dos resultados do presente estudo, que o ftalato do acetato de celulose afeta significativamente a liberação controlada do fármaco em água, enquanto que a adição de polietileno glicol aumenta ligeiramente a liberação do fármaco.Unitermos: Teofilina/microcápsulas. Microencapsulação. Ftalato de acetato de celulose. Polietilenoglicol. Microcápsulas/mecanismo de liberação. Fármacos/liberação.

A Novel Shell Material—Highland Barley Starch for Microencapsulation of Cinnamon Essential Oil with Different Preparation Methods

“…Similarly, CEO-SWSM (0.991) and CEO-UM (0.949) had the maximum R-squared value in the Higuchi kinetic equation (Figure 9b) and the first-order kinetic equation (Figure 9c), respectively [57,58]. The release process of CEO-SWSM was most consistent with the Higuchi kinetic model, and the best kinetic model for the release process of CEO-UM was the first-order kinetic model.…”