Drug-polymer interactions in controlled delivery systems: Interactions of metoprolol tartrate with Eudragit RL in films

摘要

Thin poly [ethylpropenoat-co-methyl -2-methyl propenoat-co-2-(trimethylammonium)ethylpropenoat] -chloride (Eudragit RL) films containing metoprolol tartrate were prepared containing 2.5 - 30.0% of the drug. The state and the behaviour of the metoprolol tartrate within the polymer were investigated in view of the presence of drug-polymer interactions. Results show that an interaction between drug and polymer is likely. XRPD showed that there were no crystalline structures, while DSC confirmed presence of an amorphous one-phase system by showing just one T_g. The T_g conversely, remained unchanged upon increasing drug concentration.