IBUPROFEN.

Key findings

1. 01 Topical 10% ibuprofen gel demonstrated anti-inflammatory efficacy in adolescent athletes, with drug concentration in the epidermis correlating with reduced inflammation.
2. 02 Various 5% ibuprofen topical formulations (gels, creams, mousses, sprays) exhibited differing rates and degrees of skin penetration, with Ibuspray, Ibugel, and Ibumousse showing more efficient permeation.
3. 03 An in-vitro study evaluating semi-solid topical preparations identified a 3% w/w ibuprofen clear gel as achieving the highest cumulative drug permeation.
4. 04 A 5% w/w ibuprofen cream formulation, even in suspended form, also demonstrated significant permeation in in-vitro studies.
5. 05 Ibuprofen formulations at 5% and 10% concentrations were shown to permeate human skin more rapidly and to a greater extent than diclofenac, exhibiting notable anti-inflammatory activity.

Stability

Ibuprofen exhibits maximal stability within a pH range of 5.0 to 7.0, with a pH of 6.0 considered optimal for liquid preparations. Its pKa of 4.5-4.6 is conducive to passive diffusion of the un-ionized form at the skin's physiological pH (~4.8). Formulations within a pH range of 4.2 to 5.95 have demonstrated acceptable physical stability and minimal risk of skin irritation. While practically insoluble in water, ibuprofen is highly soluble in organic solvents such as ethanol, methanol, acetone, and various vegetable oils. Effective skin permeation is significantly influenced by drug concentration, its physical state (solubilized vs. suspended), and the type of formulation, with nanosystems offering potential for enhanced diffusion and permeation.

Conflicts

• Potential drug-excipient incompatibilities are a critical consideration for ensuring formulation integrity and stability.
• Occlusive dressings or bandages should be avoided over treated areas, as this can lead to increased systemic absorption and potential unwanted systemic effects.