Pramipexole nanocrystals for transdermal permeation: Characterization and its enhancement micro-mechanism

The purpose of the study was to improve transdermal delivery of pramipexole via nanocrystals and investigate the enhancement micro-mechanism. Pramipexole nanocrystals were prepared using wet media milling method and incorporated into carbomer gel. In vitro permeation studies through rabbit ear skin indicated that the cumulative permeation amount of pramipexole from nanocrystals in 24 h was 2.75 times more than that from coarse suspension. Investigations of selective follicular closing technique indicated that approximately 33.88% of the total permeation from nanocrystals was contributed to the follicular pathway, which was confirmed by scanning electron microscopy images. In vitro permeation and in vivo pharmacokinetic studies indicated that pramipexole from nanocrystal gel showed a higher permeation profile than that from coarse suspension gel. Overall, nanocrystals could improve transdermal delivery of pramipexole through transepidermal and transfollicular pathways by the nanosized particles.