Soluplus micelles for acyclovir ocular delivery: Formulation and cornea and sclera permeability

Area of Science:

• Ophthalmology
• Pharmaceutics
• Materials Science

Background:

• Herpes simplex virus (HSV) infections affect nearly 20% of individuals, causing significant vision problems through corneal or scleral inflammation.
• Low aqueous solubility of acyclovir limits its efficacy in treating ocular HSV infections.
• Developing advanced drug delivery systems is crucial to enhance acyclovir's solubility and ocular penetration.

Purpose of the Study:

• To evaluate the potential of Soluplus and Solutol polymeric micelles for encapsulating acyclovir.
• To assess the impact of micellar encapsulation on acyclovir's solubility, corneal permeability, and scleral penetration.
• To investigate the stability and viscoelastic properties of the developed formulations for ophthalmic application.

Main Methods:

• Preparation and characterization of Soluplus and Solutol polymeric micelles with and without acyclovir.
• Assessment of micelle size, Z-potential, and acyclovir solubility.
• In vitro studies on bovine cornea and sclera to determine drug permeability, lag time, and steady-state flux.
• Evaluation of formulation stability and rheological properties.

Main Results:

• Soluplus micelles significantly enhanced acyclovir solubility and demonstrated good stability upon dilution.
• Soluplus micelles reduced the permeation lag time through the cornea.
• Formulations with Soluplus micelles led to higher acyclovir accumulation in both cornea and sclera, with approximately 10-fold greater penetration through the sclera compared to the cornea.

Conclusions:

• Soluplus polymeric micelles represent a promising formulation strategy to improve acyclovir solubility and ocular delivery.
• The enhanced scleral penetration suggests potential for delivering acyclovir to the posterior eye segment.
• This approach may lead to more effective treatments for ocular herpes simplex virus infections.