[Optimization of liberation of theophylline derivatives from Gelucire matrix tablets]

Matrix tablets containing theophylline, etofylline, dyphylline and proxyphylline were prepared with saturated polyglycolysed glycerides whose melting point was 50 degrees C and HLB were 2 and 13 (Gelucires 50/02 and 50/13), in order to eliminate the melting point influence and to have extreme values of HLB. The influence of two parameters was studied: HLB of the mixtures of Gelucires and drug solubility. Drug release was found to increase as these two parameters rose, the main factor being HLB value. Multiple linear regression was used to evaluate their influence. The mathematical model obtained was employed to optimize the release of each active ingredient from the tablets made of mixtures of the two Gelucires with HLB ranging from 3 to 4 depending on drug solubility.