The effects of the cononsolvent composition and the added drug – indomethacin– on the structure of PNIPAM-g-PEO copolymer aggregates in mixtures of ethanol and water are investigated.New data about the adsorption layer properties at the air/solution interface and the foam film stability are obtained. It is established that higher degree of copolymer grafting results in a remarkable frequency dependence of the surface rheological properties at room temperature and in a pronounced thermal sensitivity of the copolymer-drug formulation at elevated temperatures. Important input is added in view of the optimal composition of the copolymer/drug formulation aimed at possible pharmaceutical applications. It is found for example, that ethanol quantity of 10% (v/v) is the lowest limit of pharmaceutical interest, and the range of 15-20% ethanol quantity is the optimal composition for the specific polymer-drug system. The obtained results add new knowledge about the mechanisms of the drug entrapment and release events, considering the system’s composition and different temperatures.
Acknowledgement:
The financial support of NSF of Bulgarian Ministry of Education, Youth and Science by Project МU03/137 is gratefully acknowledged.
