Methods for the Development of Cationic Nanocapsules for the Topical Administration of Tretinoin: A Box-Behnken Approach, In Vitro Assessment, and Ex Vivo Epidermal Deposition Research

An exciting new direction in topical administration is the use of cationic nanocapsules. To improve the
photostability, user compliance, and pharmacodynamic effectiveness of tretinoin (TTN), we built on a new
formulation that relies on cationic nanocapsules. The nanoprecipitation process was used to create TTN
nanocapsules in order to accomplish this. A Box-Behnken design was used with the help of Design-Expert
software to statistically optimize the formulation variables. The cationic acrylic polymer weight (X1), oil volume
(X2), and total transdermal N-terminal thickness (X3) were the three independent variables that were examined.
As for the dependent variables, we chose particle size and encapsulation efficiency percentage (EE%). With an
ideal particle size of 116.3 nm and a high EE% of 83.2%, the ideal formulation displayed spherical shape under
scanning electron microscopy (SEM). When compared to its methanolic solution, photostability was enhanced
by TTN-loaded nanocapsules. Results from the in vitro release investigation demonstrated that, in contrast to
the free drug, tretinoin was released in a sustained way. The ex vivo skin penetration investigation showed
that compared to drug solution, a gel containing TTN-loaded nanocapsules caused more drug to be deposited
into the epidermal area rather than the deep skin. The skin irritation test revealed that the nanoencapsulation
of the drug decreased its irritancy compared to the free drug. Based on these findings, cationic nanocapsules
for tretinoin topical distribution seem to be a viable option