Purpose: To formulate an optimized gastric
floating drug delivery system (GFDDS) containing
glipizide with carbomers and cellulosic polymers.
Method: Central composite design (CCD) was
employed in formulating the GFDDS using hydroxypropyl
methylcellulose K4M (HPMC K4M) (A) and Carbopol 934P
(CP934P) (B), as independent variables. Floating lag
time (FLT), total floating time (TFT) and time required
to release 50 % of the drug (T50) were
selected as dependent variables. The dissolution data
obtained were fitted to various release models and the
floating profiles of the formulations analyzed.
Results: HPMC K4M loading clearly enhanced
floating properties while CP934P showed negative effect
on floating properties but was helpful in controlling
drug release. The quadratic mathematical model developed
was used to predict optimum formulations. The computer
optimization process, contour plots and response surface
plots predicted the concentration of independent
variables A and B to be 47.32 and 8.4 mg, respectively,
for maximum TFT and T50 at the same time for
least FLT. Predicted concentration of independent
variables showed the same results experimentally, with
-0.75 - 1.47 percentage errors.
Conclusion: CCD demonstrated the role of the
derived equations, contour plots and response surface
plots in predicting the values of independent variables
for the preparation and optimization of glipizide
gastric floating matrix tablet.
Keywords:
Effervescent, Floating tablet, Design of Experiment,
Release kinetics, Central composite design,
Optimization.
