Improved Dermal Delivery of FITC-BSA Using a Combination of Passive and Active Methods

This work presents results on the in vitro penetration of a model macromolecule (fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA)) through porcine skin, mediated with a microneedle skinroller (200-:m-length needle) and different novel formula- tions. After perforating the porcine skin with a microneedle skinroller, the efficiency of deliv- ering FITC-BSA via different novel formulations was evaluated and compared. Formulations, including L-"-phosphatidylcholine (PC) liposomes, double emulsions, and double-encapsulation formulations were used. High-resolution cryo-scanning electron microscopy was used to visu- alize surface morphology and cross-section of perforated porcine skin. By the use of confocal microscopy, the penetration pathway and penetration depth of FITC-BSA through the perfo- rated porcine skin under different formulations were analyzed. FITC-BSA was extracted from stratum corneum and viable skin, and analyzed by fluorimetry, indicating that there is no significant difference in the amount of FITC-BSA delivered to viable skin by PC-liposome sus- pension (12.90 ± 1.25 :g/cm 2 ) versus double-encapsulation formulations (10.47 ± 0.80 :g/cm 2 ); however, both formulations showed a significant increase as compared with an aqueous solution of FITC-BSA. In this work, double-encapsulation formulations were used in dermal delivery for the first time and combined with microneedle skinroller treatment, the results showed a high efficiency in delivering macromolecules. © 2011 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:4804-4814, 2011