Rational Design of Topical Semi-Solid Dosage Forms-How Far Are We?

Area of Science:

• Pharmaceutical Sciences
• Dermatology
• Materials Science

Background:

• Topical semi-solid dosage forms present unique challenges including skin barrier interaction, physical/chemical instability, and sensory perception.
• Current formulation design often relies on traditional methods rather than rational, science-based approaches.
• Advances in understanding skin penetration and formulation structure offer opportunities for improved design.

Purpose of the Study:

• To analyze the opportunities and constraints of rational formulation design in industrial topical drug development.
• To discuss models for drug selection based on physicochemical properties to accelerate success.
• To review the application of skin penetration science for rational formulation design.

Main Methods:

• Review of scientific literature on skin penetration, formulation design, and stability.
• Discussion of theoretical and experimental models for drug candidate selection.
• Focus on modern rheological and analytical methods for semi-solid formulation characterization and stability assessment.

Main Results:

• Rational design requires understanding skin penetration mechanisms and formulation influences.
• Drug selection based on favorable physicochemical properties is crucial for development speed and success.
• Characterization should include advanced rheology and stability testing aligned with regulatory guidelines.

Conclusions:

• Integrating scientific principles with early regulatory consideration enables successful development.
• Innovative and robust semi-solid topical formulations benefit from rational design approaches.
• Optimizing chemical stability and understanding skin penetration are key enablers for topical drug delivery.