Formulation of Topical Drug Delivery Systems Containing a Fixed-Dose Isoniazid-Rifampicin Combination Using the...

Area of Science:

• Pharmaceutical Sciences
• Dermatology
• Microbiology

Background:

• Tuberculosis (TB) is a major global health concern, with drug-resistant strains posing a significant challenge.
• Current TB treatments rely on systemic regimens, but topical drug delivery systems offer potential advantages for cutaneous tuberculosis (CTB).
• Developing localized treatments for CTB could improve efficacy and reduce systemic side effects.

Purpose of the Study:

• To develop and characterize topical self-emulsifying drug delivery systems (SEDDS) for isoniazid (INH) and rifampicin (RIF).
• To evaluate the stability and drug release properties of these formulations for potential CTB treatment.
• To assess the suitability of olive oil microemulsions for dermal drug delivery.

Main Methods:

• Quality-by-design approach for developing INH and RIF topical emulsions.
• Preformulation studies, pseudoternary diagram construction, and formulation characterization (droplet size, zeta potential, viscosity, pH, stability).
• In vitro membrane release, skin diffusion studies, and drug stability assessments.

Main Results:

• Self-emulsifying emulsions incorporating INH and RIF were successfully prepared.
• Olive oil microemulsions exhibited favorable characteristics for dermal delivery, though drug diffusion into/through skin was unquantifiable.
• Rifampicin showed degradation susceptibility at higher temperatures and lower pH; however, drug release was confirmed from all formulations.

Conclusions:

• Topical self-emulsifying systems can facilitate direct treatment of cutaneous tuberculosis.
• Olive oil microemulsions represent a promising vehicle for CTB topical therapy.
• Further research is needed to optimize formulations and quantify skin penetration for effective localized treatment.