Bacterial nanocellulose patches as a carrier for hydrating formulations to improve the topical treatment of nail diseases

Bacterial nanocellulose has been widely investigated for wound healing applications, mainly due to its mois-turizing capabilities and biocompatibility. Even though the topical therapy of nail diseases could benefit from these properties, this application has not yet been investigated. Therefore, actively hydrating nail patches based on bacterial nanocellulose were developed to improve the delivery of ciclopirox olamine and Boswellia serrata extract through the nail plate. The nanocellulose matrix was used to enable the application of hydration enhancing solutions based on glycerol and urea as a mechanically stable patch. While the favorable mechanical characteristics of the material remained unchanged, an increase of the incorporated glycerol concentration enhanced the transparency and wetting capacity of the patches. A biphasic drug release from the patches could be observed for drug and extract with a faster release for the hydrophilic ciclopirox olamine. High glycerol concentrations correlated with increased cumulative release and permeation through keratin films for drug and extract, demonstrating the hydration driven permeation enhancement. Patches containing ciclopirox olamine showed strong antimycotic effects against relevant pathogens for onychomycosis. The present finding proposed the combination of bacterial nanocellulose with glycerol, urea and different drug as a promising platform for the local treatment of nail diseases.