Brazilian Journal of Pharmaceutical Sciences
On-line version ISSN 2175-9790
ROJAS, John; GONZALEZ, Cesar; RICO, Carolina and SAEZ, Oswaldo. Formulation of a modified release metformin. HCl matrix tablet: influence of some hydrophilic polymers on release rate and in-vitro evaluation. Braz. J. Pharm. Sci. [online]. 2011, vol.47, n.3, pp.483-493. ISSN 2175-9790. http://dx.doi.org/10.1590/S1984-82502011000300006.
Metformin hydrochloride is an antidiabetic agent which improves glucose tolerance in patients with type 2 diabetes and reduces basal plasma levels of glucose. In this study, a simplex centroid experimental design with 69 runs was used to select the best combination of some hydrophilic polymers that rendered a 24 h in-vitro release profile of metformin.HCl. The Korsmeyer-Peppas model was used to model the dissolution profiles since it presented the best fit to the experimental data. Further, a cubic model predicted the best formulation of metformin.HCl containing polyvinyl pyrrolidone, ethyl cellulose, hydroxypropyl methyl cellulose, carrageenan, sodium alginate, and gum arabic at 6.26, 68.7, 6.26, 6.26, 6.26 and 6.26 % levels, respectively. The validation runs confirmed the accuracy of the cubic model with six components for predicting the best set of components which rendered a once-a-day modified release hydrophilic matrix tablet in compliance with the USP specifications.
Keywords : Metformin [release profile]; Metformin.HCl [modified release]; Metformin.HCl [in-vitro evaluation]; Hydrophilic polymers [influence]; Hydrophilic polymers [drugs release]; Korsmeyer-Peppas model [dissolution profiles].