Bilayered osmotically controlled Gastrointestinal Therapeutic System of
atenolol has been obtained by using
cellulose acetate pseudolatex prepared by
polymer emulsification method. Various factors such as orifice size, coating thickness, amount and nature of polymeric
excipients, and amount of osmotic agent influence the drug release from GITS. Therefore, in the present study a 7-factor, 12-run Plackett-Burman screening design was employed to evaluate the formulation variables for
atenolol GITS coated with CA pseudolatex. The variables studied were orifice size, %coating
weight gain, amounts of
sodium chloride. Polyox N80 and 303, and
Carbopol 934P and 974P on drug release. The screening design has revealed that orifice size, %coating
weight gain and amount of
Carbopol 934P have prominent influence on in-vitro
atenolol release. The response variable was cumulative percent
atenolol released (Y) in 24 h with constraints on percent release at 2, 6, 12 and 18 h. The polynomial equation obtained was Y24 = 149.82 - 0.13 X1 - 0.34X2 + 0.06X3 - 0.13X4 - 0.23X5 - 76.25X6 - 2.46X7. The results indicated that the drug release under constrained conditions was influenced by the factors with decreasing order of importance as %coating
weight gain >
Carbopol 934P > Polyox N80 >
Carbopol 974P > Polyox 303 > amount of
sodium chloride > orifice size.