Nanoparticle-loaded gels for topical delivery of nitrofurazone: Effect of particle size on skin permeation and retention

In this study, the effect of particle size on skin permeation and retention of nitrofurazone (NTZ) from nano-particle-loaded gels (NP-gels) was investigated to identify the suitable particle size of NTZ nanoparticle for topical delivery in order to achieve high deposition and low permeation of NTZ in the skin. NTZ nanosuspensions (NTZ-NSs) with three different particle size (299, 611, 906 nm) were prepared using wet media milling technique by adjusting milling speed and milling time, and then incorporated in carbopol gels for topical application. SEM and XRPD results showed that NTZ nanoparticles were well encapsulated in the gels network. The dissolution and the skin permeation of NTZ from NP-gels were particle size dependent and in an order of 299 nm > 611 nm > 906 nm, however, the skin deposition was in the order of 611 nm > 299 nm > 906 nm. The results demonstrated that the skin permeation and retention of NTZ from NP-gels were particle size dependent and the optimal size range was around 611 nm for topical application.