Thermoanalytical and Microscopic Investigation of Interaction between Paracetamol and Fatty Acid Crystals

The objective of this study was to investigate the possibility of interaction between paracetamol and saturated fatty acids. Although literature is replete with the interaction study of fatty acids with different drugs, few have examined the interaction with NSAIDs. Keeping in view the crystalline nature of paracetamol and fatty acids and to provide the intimate contact between the interacting molecules, crystals of binary mixture of drug with fatty acids were prepared by the solvent evaporation method. These crystals were subjected to FT‐IR, DSC, XRD, optical microscopy, SEM and AFM. DSC and XRD studies were unable to detect any interaction. Some changes were observed in FT‐IR spectrum of a binary mixture of drug with fatty acid. A better probe into interaction was obtained by microscopic techniques, especially atomic force microscopy.