Chandrasekran-paul (1982) made an equation of drug release from matrix system as follows:In this paper a simplified expression has been deduced from it within ordinary range of experimental time and with appropriate values of K. The cumulative amount of drug release may vary in directproportion to the square root of time with an intercept,that is,The release behaviour of both nifedipine patch and propranolol patch has fit the expression with good correlation coefficient.The re0lease data of hydrocortisone creams (Shah,1989)also can be described by the same expression.Compared with Higuchi’s equation,the presence of the intercept,A〃,may be relative to drug dissolution characteristics
