Conventional oral dosage forms provide a specific drug concentration in
the systemic circulation without offering any control over the rate of
drug delivery. Controlled-release drug delivery systems (CRDDS) provide
drug release at a predetermined, predictable, and controlled rate. It
was attempt to develop a gastro retentive drug delivery system of anti
hypertensive drug using different polymers like that HPMCK4M,
Xanthangum, PolyoxWSR303as matrixing agent, swelling agent, respectivel.
A simplex lattice design was applied to combined effect of three
formulation variables (ie, amount of HPMCK4M (X1), xanthangum (X2), and
PolyoxWSR303 (X3). Results of multiple regression analysis indicated
that low level of X1 and X 2 and high level of X3 should be used to
manufacture the tablet formulation with desired in % swelling index and
% drug release profile . When Polyox 303 was used, % swelling index
increased, with increase on the total amount of drug released.
Decreasing the amount of HPMC K4M while maintaining the total amount of
polymer constant increased the release rate and total amount released.
Decreasing the total amount of polymer decreases the swelling and work
of penetration,