DSC screening of potential prochlorperazine-excipient interactions in preformulation studies

Differential scanning calorimetry was used to examine the thermal behaviour of mixtures of the drug prochlorperazine with standard excipients, to asse ss potential interactions, and of mixtures with cyclodextrins, to investiga te inclusion complexation which could increase the photostability of the dr ug. For most of the excipients (magnesium stearate, stearic acid, Explotab( R), Ac-Di-Sol(R), Encompress(R) and Ludipress(R), lactose and Starch 1500) disappearance or broadening of the melting endotherm of the drug indicated interactions. Lubritab(R) was the only 'inert' excipient tested. Mixtures o f prochlorperazine and the cyclodextrins gave incomplete inclusion complexa tion as;shown by only partial disappearance of the melting endotherm of the drug.