IN-VIVO VALIDATION OF THE RELEASE RATE AND PALATABILITY OF REMOXIPRIDE-MODIFIED RELEASE SUSPENSION

Remoxipride, a D2-dopamine receptor antagonist, is well tolerated and completely absorbed after oral administration. Because of its extremel y bitter taste, an oral palatable suspension was developed by using a taste-masking microencapsulation. The bioavailability of remoxipride w as investigated in two studies in healthy volunteers after administrat ion of a 100-mg dose in suspension. The first study used a capsule as reference, and the second study a plain solution. Taste assessment was carried out in the second study. The extent of bioavailability was th e same when comparing the oral suspension to a capsule and to a plain solution. However, the rate of absorption is delayed, and T(max) was 3 .0 hr after the suspension, 1.0 hr after the oral solution, and 1.6 hr after the capsule. The release rate in vitro from the suspension was determined by applying the USP-paddle method. By using numerical convo lution and deconvolution, the release rates in vivo and in vitro were shown to be similar when using water with 0.5% sodium lauryl sulfate a s dissolution liquid. The taste-masked oral suspension is suitable for full-scale production, with good control of the encapsulation process and of the preparation of a suspension.