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

Management of Minor Ailments by Community Pharmacists in Cebu, Philippines – An Exploratory Study

Background@#Community pharmacists play a central role in the management of minor ailments and their clinical knowledge is vital in improving treatment outcomes of these ailments. The provision of minor ailment service in developed countries has been successful yet the practice in the Philippines has not been documented. @*Objectives@#The aim of this study was to document the involvement of community pharmacists in the management of minor ailments, the practices, and the perceived challenges in the provision of pharmacy service. @* Methods@#This was an exploratory descriptive study. Using qualitative research technique, a guided interview questionnaire was employed for data gathering. The practices employed and perceived challenges encountered by pharmacists were interpreted using conventional content analysis. @* Results@#Colds, cough, skin allergy, diarrhea were the four most common ailments managed by community pharmacists. Pharmacists had underdeveloped roles in consultation. Community pharmacists were knowledgeable on the causes of the minor ailments and the medications dispensed were compliant with approved product indications. The absence of institutional guidelines (66%), lack of ailment-specific training (100%), insufficient clinical skills (76.7%), and a dominant patient self-selection behavior for OTC medicines (73.3%) were perceived as challenges in the provision of minor ailment services.@*Conclusion@#Community pharmacists managed common ailments with non-prescription medicines however consultation roles were found to be underdeveloped.