Tranexamic Acid-Based Polymeric Micellar Hydrogel for Enhanced Dermal Delivery and Melanin Reduction.

Area of Science:

• Pharmaceutical Sciences
• Dermatology
• Nanotechnology

Background:

• Oral and intralesional tranexamic acid (TXA) for melasma carry systemic and invasive risks.
• Topical TXA exhibits poor skin permeability and retention due to its physicochemical properties.
• Existing treatments necessitate improved delivery systems for enhanced efficacy and safety.

Purpose of the Study:

• To develop a novel topical polymeric micelles (PMs) based hydrogel (Hgel) incorporating 5% w/v TXA.
• To enhance skin permeation, melanocyte targeting, and retention of TXA for melasma treatment.
• To evaluate the safety, stability, and efficacy of the developed TXA-PMs Hgel.

Main Methods:

• Polymeric micelles (PMs) loaded with TXA were formulated and characterized for particle size and entrapment efficiency.
• TXA-PMs were incorporated into a Carbopol 934P hydrogel (Hgel) for improved skin retention.
• In vitro release kinetics, skin permeation, retention studies, cytotoxicity, in vivo toxicity, biocompatibility, and melanin inhibition assays were performed.

Main Results:

• TXA-PMs Hgel exhibited optimal particle size (47.0 ± 3.6 nm) and high entrapment efficiency (81 ± 1.4%).
• The hydrogel demonstrated sustained diffusion-controlled release (>97% up to 48 h), significantly enhanced skin permeation (93%) and retention (160%) compared to a marketed product.
• The formulation showed excellent safety profiles and significantly reduced melanin concentration (>50% inhibition) in B16F10 cells.

Conclusions:

• TXA-PMs Hgel represents a promising, safe, and effective topical therapeutic approach for melasma.
• The formulation offers enhanced drug delivery, superior skin retention, and potent melanin reduction.
• The simple, scalable, and industry-amenable production method supports its potential for commercialization.