Propranolol:methacrylic acid copolymer binding interaction

The polyanionic form of methacrylic acid:methacrylic acid methyl ester copolymer reacts readily with propranolol.HCl to give a sparingly soluble complex at saturation equilibrium. Propranolol: methacrylic acid copolymer complex is characterized by differential thermal analysis, and IR and UV spectroscopic methods. Propranolol content is found to be 68% in the complex. The value of the Hill coefficient (1.5) indicates that there is a high degree of positive cooperative interaction between propranolol and the polymer.