Comparison between percutaneous and subcutaneous routes of administration of apomorphine in rabbit

Apomorphine (0.5 mg/kg) was administered subcutaneously and percutaneously to rabbit in order to compare the pharmacokinetic data obtained according these two different routes. For the percutaneous administration, an apomorphine gel was prepared by dissolution of apomorphine in an hydroxypropylmethylcellulose gel of medium viscosity. The evaluation of plasma levels after percutaneous route showed an absorption in all the animals. The time to peak plasma concentration (29.4 +/- 7.8 min) was close than after the subcutaneous route (25.8 +/- 4.9 min). The absorption of apomorphine was of 90% at minute 68 and minute 321 min after the subcutaneous and the percutaneous route, respectively. The peak plasma concentration and the area under the curve were significantly greater with the subcutaneous route. The bioequivalence of the percutaneous route was 35% of the subcutaneous administration. Those data suggested that the percutaneous route of apomorphine could be evaluated in humans to test its efficacy in the treatment of motor fluctuations in parkinsonian patients.