Abstract: The objective of the present study was to evaluate the
potential of hollow microneedles for enhancing the transdermal
delivery of Bovine Serum Albumin (MW~66,000 Da)-Fluorescein
Isothiocyanate (BSA-FITC) conjugate, a hydrophilic large molecular
compound. Moreover, the effect of different formulations was
evaluated. The series of binary mixtures composed of propylene
glycol (PG) and pH 7.4 phosphate buffer solution (PBS) was
prepared and used as a medium for BSA-FITC. The results showed
that there was no permeation of BSA-FITC solution across the
neonatal porcine skin without using hollow microneedles, whereas
the cumulative amount of BSA-FITC released at 8 h through the
neonatal porcine skin was about 60-70% when using hollow
microneedles. Furthermore, the results demonstrated that the higher
volume of PG in binary mixtures injected, the lower cumulative
amount of BSA-FITC released and release rate of BSA-FITC from
skin. These release profiles of BSA-FITC in binary mixtures were
expressed by Fick-s law of diffusion. These results suggest the
utilization of hollow microneedle to enhance transdermal delivery of
protein and provide useful information for designing an effective
hollow microneedle system.