Muhammad Ramzan, Muhammad Akhlaq, Muhammad Zeeshan Danish, Satar Bakhsh, Haroon Khan, Abid Hussain.
Pharmacokinetic evaluation of clarithromycin oral controlled release matrix tablets for desired bioavailability and improved patient compliance.
Gomal J Med Sci Jan ;13(4):217-22.

Background: Controlled release drug delivery systems release drug at controlled rate over desired period of time. It helps to maintain constant drug concentration in plasma and improves the patient compliance. Material & Methods: The study aims to design, formulate and evaluate controlled release matrix tablets of Clarithromycin were formulated at different drug-to-polymer (D:P) ratios (10:3, 10:4 and 10:5) using Eudragit RS 100, Methocel® polymers as release retarding agents. The matrices were prepared by direct compression and wet granulation techniques. Dissolution studies were performed in phosphate buffer (PH 7.4) using Pharma Test Dissolution Apparatus. Different preformulation parameters (diameter, thickness, hardness, friability and weight variation tests), drug release kinetics (kinetics model; 1st-Order, Zero-Order, Higuchi, Hixon Crowell’s and Power Law) and dissolution profiles comparison with reference standard tablets. Results: It was observed that the matrices having polymers with more concentrations extended the drug release rates as compared to the matrices having smaller amounts. The matrices released the drug by anomalous Fickian diffusion mechanism and reference standard Clarion® XR tablets does not follow Power Law (n=0.125). The tests matrices showed no similarity with reference standard Clarion® XR tablets dissolution profiles. There was no significant difference between Tmax values of test and reference formulations (p≥0.05) found for in-vivo studies. Similarly, no significant difference was observed between the values of AUC0-∞ (p=0.19) and the values of Cmax (p=0.06) of the two preparations. Conclusion: The once daily controlled release matrix tablets of Clarithromycin can successfully be formulated using hydrophilic polymers.

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