Effect of Terpenes on the Enhancement of Skin Permeation of Lipophilic Drugs: A Systematic Review

Objectives. The stratum corneum (SC) remains an obstacle to the passage of drugs applied topically. Severalinvestigations have focused on enhancing penetration through SC by integrating permeationenhancers (PE) into drug formulation. Terpenes are among PE utilized in formulations and categorized regulatory bodies as generally recognized safe (GRAS). This study aimed comparatively analyze skin permeation effect terpenes lipophilic drugs.Methods. present reviewed effects small-molecule using original research published between 2000 - 2022 retrieved from PubMed®. search phrase used was (lipophilic drug) AND (terpene) (permeation enhancer).Results. increase percutaneous small molecule 1.06 – 256.80-fold. Linear correlation analysis terpenes’ cLog P with enhancement ratio (ER) revealed moderate strong positive correlations pig (r = 0.21) mouse 0.27), rat 0.41) human 0.67), respectively. Drug is a poor -0.06) predictor enhancement. higher than 2.40 had ER greater 10. Higher ERs (>30) were recorded for nerolidol, carvacrol, borneol, terpineol, limonene, menthone, pulegone, menthol terpene-chemical enhancers.Conclusion. terpene-based chemical enhancers (CPE) strongly correlated across skin. Non-polar groups hydrogen bond interactions lipid enhance cutaneous drugs.