Characterization and drug-excipient compatibility study of bromopride by DSC, FTIR and HPLC

Given that interactions between the active principle and formulation excipients can modify the chemical composition, stability and bioavailability of a drug, thus compromising its effectiveness, the present study aims to evaluate the compatibility of Bromopride with commonly used pharmaceutical excipients, which has been characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction. For such a purpose, samples of pure drug, 10 excipients and binary drug/excipient mixtures were analyzed in a ratio of 1:1 (m/m) by DSC, FTIR and high performance liquid chromatography (HPLC). DSC results reveal a probable interaction of Bromopride with the majority of excipients under study, except for mannitol and talc. The FTIR results indicate some interaction of BROM with all studied excipients. However, HPLC results reveal that only colloidal silicon dioxide, dicalcium phosphate dihydrated, magnesium stearate and microcrystalline cellulose were incompatible with Bromopride, as content reduction ranging between 16 and 42% was reached, and chemical interactions of excipients croscarmellose sodium, hydroxypropyl-methyl-cellulose, lactose monohydrate and polyvinylpyrrolidone with the API were not confirmed by the HPLC, despite the fact that they have been pointed out by the DSC and FTIR. The present study indicates that BROM undergoes interaction/incompatibility when mixed with colloidal silicon dioxide, dicalcium phosphate dihydrate, magnesium stearate, and microcrystalline cellulose.