Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Evaluation of Controlled Release Theophylline Microspheres Prepared with Cellulose Acetate Using Solvent Evaporation Method

Sunit K Sahoo¹ , Satyabrata Barik¹, Gourhari Dehury¹, Subhakanta Dhala¹, Subhakanta Kanungo¹, Bhakti B Barik², Kishore K Puhan³

¹University Department of Pharmaceutical Sciences, Utkal University, Vani-Vihar, Bhubaneswar, Orissa. Pin- 751004; ²College of Pharmacy, Jazan University, P.O. Box 114, Jazan, 45142, Kingdom of Saudi Arabia; ³Glenmark Research Center, Nasik, India.

For correspondence:- Sunit Sahoo Email: sahoosunitkumar@rediffmail.com

Received: 8 July 2010 Accepted: 23 January 2011 Published: 20 April 2011

Citation: Sahoo SK, Barik S, Dehury G, Dhala S, Kanungo S, Barik BB, et al. Evaluation of Controlled Release Theophylline Microspheres Prepared with Cellulose Acetate Using Solvent Evaporation Method. Trop J Pharm Res 2011; 10(2):195-201 doi: 10.4314/tjpr.v10i2.11

© 2011 The authors.
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Abstract

Purpose: To formulate theophylline microspheres with cellulose acetate using solvent evaporation method and evaluate the effect of various processing factors on their characteristics.

Methods: Microspheres containing theophylline were prepared with a hydrophilic, biocompatible polymer - cellulose acetate - by an emulsion solvent evaporation technique using an acetone/liquid paraffin system containing Span 80 as a surfactant. The effect of processing factors, e.g., varying drug/polymer ratio (1:1, 1:2, 1:3) and temperature (10 and 35 °C) on microsphere characteristics and drug release were examined. Similarly, microspheres with a drug/polymer ratio of 1:3 incorporating Span 20 were also also prepared and evaluated.

Results: The microspheres were white, free-flowing and spherical. The yield varied from 73.0 to 87.5 % while entrapment efficiency was in the region of 71.8 to 92.4 %. High drug/polymer ratio, Span 80 (surfactant) and processing temperature between 10 and 30 °C produced formulations with better drug entrapment efficiency. High drug/polymer ratio, low processing temperature and low HLB value of surfactant enhanced the sustained drug release characteristics of the microspheres.

Conclusion: The combination of three suitable factors - Span mixture (with HLB value of 4.3), processing temperature of 10 °C and drug/polymer ratio of 1:3 - produced a suitable controlled release theophilline microsphere formulation which could be effective for the management of asthma.

Keywords: Microsphere, Emulsion solvent evaporation, Theophylline, Temperature, HLB value