High throughput screening of transdermal formulations.

Area of Science:

• Pharmaceutical Sciences
• Biomaterials Science
• Chemical Engineering

Background:

• Transdermal drug delivery offers advantages but is limited by low skin permeability.
• Identifying effective chemical enhancers for skin penetration is challenging due to complex interactions.
• Current formulation screening methods, like Franz diffusion cells, are time-consuming and resource-intensive.

Purpose of the Study:

• To develop and validate a novel high throughput (HTP) method for rapid screening of transdermal enhancer formulations.
• To assess the efficiency of the HTP method compared to traditional Franz diffusion cells.
• To identify effective enhancer combinations for improving skin permeability.

Main Methods:

• Developed an HTP method utilizing skin conductivity and mannitol penetration.
• Performed over 100 simultaneous tests daily.
• Validated HTP predictions using Franz diffusion cells with model enhancers: sodium lauryl sulfate (SLS) and dodecyl pyridinium chloride (DPC).

Main Results:

• HTP screening identified mixtures of SLS and DPC as significantly more effective than individual enhancers for transdermal transport.
• Maximum enhancement was observed with near-equimolar SLS:DPC mixtures.
• HTP method predictions correlated well with Franz diffusion cell results, confirming the efficacy of surfactant mixtures.

Conclusions:

• The novel HTP method enables rapid and efficient screening of enhancer formulations for transdermal applications.
• This method facilitates the discovery of novel and effective enhancer mixtures.
• The findings contribute to a better understanding of enhancer interactions and their effects on skin permeability.