Loratadine belongs to second generation antihistamine (H1) drug and is known to form cocrystal with succinic acid in stoichiometry of 1:1 using slurry method. This study was conducted to further investigate cocrystal phase stability upon compression. Sample of cocrystal phase was compressed with various compression force into tablet form on 10 mm diameter punch. Then, the tablet was characterized using Differential Thermal Analysis (DTA), X-ray Powder Diffraction (XRPD), and Scanning Electron Microscope (SEM). According to tensile strength profile, cocrystal phase shows better mechanical property as it has higher tensile strength value compared to loratadine alone. DTA thermograms exhibited succinic acid characteristic peak alongside with endothermic peak of cocrystal phases which were compressed on higher force. It suggests that cocrystal undergoes partial dissociation to its starting components under compression. Powder diffractograms showed reduced intensity of tableted cocrystal compared to the powder one for all compression force, indicating a decrease in crystallinity. SEM photomicrograph observed a loss of particle boundaries of cocrystal upon compression, as sintering phenomena occurred. It is predicted that compression force can influence physical stability of cocrystal of loratadine-succinic acid by driving dissociation and sintering phenomena.

Key words: cocrystal, loratadine, succinic acid, slurry, stability study, compression force