Drug-Matrix Interactions in Nanostructured Materials Containing Acetyl Salicylic Acid Using an Enteric Polymer As a Coating

摘要

Infrared spectra of nanostructured materials previously obtained and studied as controlled release devices were recorded in order to reveal drug-matrix interactions.These nanostructured materials contain acetyl salicylic acid(ASA)as the drug and the enteric copolymer poly(methacrylic acid methyl methacrylate)as the matrix.Thus,carboxylic interactions are expected to be operating.However the complex nature of the carboxylic acid carbonyl signals in the IR region resulted weak evidence about these interactions.However,using the density functional theory formalism,a stable complex drug--copolymer through the carboxyl/ASA-carboxyl/copolymer groups can be suggested as the main type of interaction in this system.It was demonstrated that this complex is as stable as the complex formed between ASA molecules.Raman spectra of nanostructured materials afforded additional information through the signals corresponding to the complex theoretically predicted.