Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Optimization and Development of Swellable Controlled Porosity Osmotic Pump Tablet for Theophylline

Prakash B Rao¹ , M Geetha¹, N Purushothama², Utpal Sanki³

¹Department of Pharmaceutics, Visveswarapura Institute of Pharmaceutical Sciences, Bangalore; ²Strides Arco Lab Limited, Bangalore; ³Department of Pharmaceutics, Government College of Pharmacy, Bangalore, India.

For correspondence:- Prakash Rao Email: bsprao@hotmail.com Tel:+918026711851

Received: 9 Aug 2008 Accepted: 17 Jan 2009 Published: 23 June 2009

Citation: Rao PB, Geetha M, Purushothama N, Sanki U. Optimization and Development of Swellable Controlled Porosity Osmotic Pump Tablet for Theophylline. Trop J Pharm Res 2009; 8(3):247-255 doi: 10.4314/tjpr.v8i3.9

© 2009 The authors.
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Abstract

Purpose: To develop swellable controlled porosity osmotic pump tablet of theophylline and to define the formulation and process variables responsible for drug release by applying statistical optimization technique.

Methods: Formulations were prepared based on Taguchi Orthogonal Array design and Fraction Factorial design for core and coating, respectively. The tablets were prepared by direct compression and wet granulation methods; spray coated with ethyl cellulose solution containing varying amounts of PEG 400 and plasdone. Drug release from the osmotic drug delivery system was studied using USP Type I paddle type apparatus. The membrane morphology of the delivery system was determined by scanning electron microscopy (SEM).

Results: Optimization results indicated that the release rate of theophylline from the swellable controlled porosity osmotic pump tablet is directly proportional to the levels of osmotic agent, solubilizing agent and pore former in the tablet core and the membrane, respectively. SEM showed the formation of pores in the membrane through which drug release occurred. The best formulation showed 98.2 % drug release and complied with USP requirements.

Conclusion: The results confirmed that the factors responsible for drug release were osmotic agents (core) and pore former (membrane). Also, the preparation of swellable controlled porosity osmotic pump tablet was facilitated by coating the core tablet with pore forming agent, thus eliminating the need for the more expensive laser drilling.

Keywords: Swellable, Controlled Porosity, Osmotic Pump Tablet, Taguchi Orthogonal design, Fraction factorial design, Osmotic agent, Pore former, Scanning electr