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Original
Research Article
Optimization and
Development of Swellable Controlled Porosity Osmotic
Pump Tablet for Theophylline
B. Prakash 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:
E-mail:
bs_prao@hotmail.com
or
bprao_1111@rediffmail.com Fax:
+91-80-26711851
Received: 9 Aug
2008
Revised accepted: 17 Jan 2009
Tropical
Journal of Pharmaceutical Research, June 2009; 8(3):
247-255
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
electron microscopy. |
