Implementing Central Composite Design for Developing Transdermal Diacerein-Loaded Niosomes: Ex vivo Permeation and In vivo Deposition

Background: Niosomes are surfactant-based vesicular nanosystems that proved their efficiency in transdermal delivery by overcoming skin inherent anatomic barrier; startum corneum. Central composite design is an efficient tool for developing and optimizing niosomal formulations using fewer experiments. Objective: The objective of this study was to prepare niosomes as a transdermal delivery system of diacerein using film hydration technique, employing central composite design, for avoiding its oral gastrointestinal problems. Methods: Three-level three-factor central composite design was employed for attaining optimal niosomes formulation with the desired characteristics. Three formulation variables were assessed: amount of salt in hydration medium (X-1), lipid amount (X-2) and number of surfactant parts (X-3). DCN-loaded niosomes were evaluated for entrapment efficiency percent (Y-1), particle size (Y-2), polydispersity index (Y-3) and zeta potential (Y-4). The suggested optimal niosomes were subjected to further characterization and utilized as a nucleus for developing elastic vesicles for comparative ex vivo and in vivo studies. Results: The values of the independent variables (X-1 , X-2 and X-3) in the optimal niosomes formulation were 0 g, 150 mg and 5 parts, respectively. It showed entrapment efficiency percentage of 95.63%, particle size of 436.65 nm, polydispersity index of 0.47 and zeta potential of -38.80 mV. Results of ex vivo permeation and skin deposition studies showed enhanced skin permeation and retention capacity of the prepared vesicles than drug suspension. Conclusion: Results revealed that a transdermal niosomal system was successfully prepared and evaluated using central composite design which will result in delivering diacerein efficiently, avoiding its oral problems.