The Effect of Polymer Blends on the Formulation of Sustained Release Ciprofloxacin Matrix Tablets

Abstract

Background: The application of polymers to sustain drug release is increasingly becoming popular and the use of polymer blends provides an alternative method to developing new pharmaceutical raw materials.
Objective: This work aims to study the effect of polymer blends of xanthan gum (X), hydroxypropylmethyl cellulose (HPMC) and Chrysophyllum albidum gum (CAG) on the mechanical properties and release rate of ciprofloxacin tablet.
Method: Ciprofloxacin tablets prepared by direct compression was evaluated for weight uniformity, friability and hardness. The time taken for 50 % (T₅₀) and 75 % (T₇₅) drug release were obtained and the in vitro release data were fitted into drug kinetics models to determine the mechanism of drug release.
Result: The tablets showed satisfactory mechanical strength. The rank order of tablet strength for the various blends is CAG-HPMC > CAG-X-HPMC > CAG-X. All the formulations with polymer blends had higher values of T₅₀ and T₇₅ than formulations containing single polymers. An increase in the proportion of CAG in formulation containing CAG-X (in ratio 2:1) resulted in almost a two- fold sustained drug release with T₅₀ and T₇₅ values of 4.4 and 7.1 hrs respectively. Generally, a blend of the three polymers resulted in a slower drug release. The proportion of polymers in the blend had no significant (p>0.05) effect on drug release rate in formulations containing the three polymers. Higuchi model was the most prominent model while the mechanism for drug release was super case II transport.
Conclusion: This study highlights the potentials of polymer blends in the design and formulation of sustained release ciprofloxacin matrix tablets.

Keywords: Polymer blend, Sustained release, Ciprofloxacin, Xanthan gum, Chrysophyllum albidum gum