9 research outputs found
Spectroscopic and electrochemical studies of cocaineâopioid interactions
Abstract The drugs of abuse cocaine (C), heroin (H), and morphine (M) have been studied to enable understanding of the occurrence of cocaineâopioid interactions at a molecular level. Electrochemical, Raman, and NMR studies of the free drugs and their mixtures were used to study drugâdrug interactions. The results were analyzed using data obtained from quantum-mechanical calculations. For the cocaineâmorphine mixture (CâMH), formation of a binary complex was detected; this involved the 3-phenolic group and the heterocyclic oxygen of morphine and the carbonyl oxygen and the methyl protons of cocaineâs methyl ester group. NMR studies conducted simultaneously also revealed CâMH binding geometry consistent with theoretical predictions and with electrochemical and vibrational spectroscopy results. These results provide evidence for the occurrence of a cocaineâmorphine interaction, both in the solid state and in solution, particularly for the hydrochloride form. A slight interaction, in solution, was also detected by NMR for the cocaineâheroin mixture. Figure "Schematic representation of the proposed model for cocaine:morphine salt interaction