Evaluation of solid-state thermal stability of donepezil in binary mixtures with excipients using instrumental techniques

Donepezil (Don) is one of the main compounds used in the therapy of Alzheimer’s disease. In this study, donepezil hydrochloride was investigated for solid-state compatibility with several pharmaceutical excipients like calcium lactate (CaL), mannitol (Man), magnesium stearate (MgSt), anhydrous lactose (LAnh), talc (T), magnesium citrate (MgC), sorbitol (Sb), silica (SiO2), polyvinylpyrrolidone K30 (PVP), sodium carboxymethylcellulose (NaCMC) and starch (St) under ambient conditions, by ATR–FTIR spectroscopy and PXRD data, and later by thermoanalytical techniques (TG/DTG/HF), in order to evaluate the thermal-induced interactions. The instrumental investigations carried at ambiental temperature revealed no interaction between Don and selected excipients, while thermal treatment induced interactions between components in eight binary mixtures, except the ones containing magnesium citrate, talc and polyvinylpyrrolidone.