Central Composite Design for the Development and Evaluation of Floating-mucoadhesive Tablets of Gliclazide

Background: Gliclazide assimilation rate from the gastrointestinal (GI) tract is slow and inconstant, which may be either due to poor dissolution or poor permeability of the drug across the GI membrane. Objective: The present investigation deals with the formulation of floating-mucoadhesive tablets of gliclazide for oral administration using the central composite design by direct compression technique, using HPMC K4M and Carbopol 934 as release controlling polymers and sodium bicarbonate as an effervescent agent. Methods: Central composite design was employed to quantify the effect of three factors-concentration of HPMC K4M (X-1), the concentration of Carbopol 934 (X-2), and concentration of sodium bicarbonate (X-3) on floating lag time, drug release and mucoadhesive time of the formulation. Results: The results revealed that floating lag time decreases with a rise in the concentration of sodium bicarbonate, drug release was highest at low levels of HPMC and Carbopol and mucoadhesive time was highest at a high level of Carbopol. Conclusion: The optimized batch (F-7) shows a mucoadhesive time of 23 minutes 27 seconds, floating lag time of 22 seconds and in vitro cumulative percentage of drug release 86.73 % in 10h. From the investigation, it can be summarized that the gastro-retentive drug delivery can be utilized to enhance bioavailability and gastric residence time of the drugs.