Physiochemical interactions of praziquantel, oxamniquine and tablet excipients.

A differential scanning calorimetry and infrared spectrophotometry study of potential interactions between oxamniquine and praziquantel, two synergistic anti-parasitic drugs, indicated that they did not interact on fusion. Mixtures of the two drugs with each of nine common pharmaceutical excipients (Ac-Di-Sol, Avicel, Crospovidone, calcium phosphate, magnesium stearate, starch, lactose, PEG 6000, stearic acid) appeared to interact only with stearic acid. These results suggested that a combination solid dosage form was feasible.