Targeted transfollicular delivery of artocarpin extract from Artocarpus incisus by means of microparticles

Artocarpin (Ar), an extract of heartwood of Artocarpus incisus, possesses potent 5α reductase inhibitory effect. The penetration of Ar into the deeper layers of the skin where androgen receptors are present is limited. Therefore, this study was aimed to prepare alginate/chitosan (ACS) microparticles for targeted transfollicular delivery. It was found that a suitable particle size ranging from 2 to 6 μm can be prepared using the ionotropic gelation technique. Entrapment efficiency of Ar in ACS microparticles was 18.7 ± 1.7%. The release of Ar from the ACS microparticles over 6 h was 0.7% of the loading dose suitable for a long-term release of Ar in the follicular ducts. The optimal growth suppression of the hamster flank organs could be achieved by topical application of Ar-ACS microparticles with a content of 0.1 mg in 5 mg microparticles to one hamster flank while the other flank (intraspecies control) showed the normal growth of the flank organs and Ar at the same concentration in solution form could not suppress the growth of the flank organs to the same extent. The efficiency of Ar 0.1 mg loaded in ACS microparticles was shown to be comparable to a dose of 1 mg Ar applied as solution. However, Ar formulated in microparticles did not show significant systemic action compared to the dermal application of an Ar solution and a flutamide preparation (1 mg) as positive control.