Trends in advanced oral drug delivery system for curcumin: A systematic review

Although curcumin is globally recognized for its health benefits, its clinical application has been restricted by its poor aqueous solubility and stability. To overcome these limitations, nanocarrier-based drug delivery systems (NDS) are one of the most effective approaches being extensively explored over the last few decades to improve curcumin's physicochemical and pharmacological effects. Various NDS could provide productive platforms for addressing the formulation challenge of curcumin, but evidence of such systems has not been summarized. This study aimed to systematically review current evidence of lipid and polymer-based NDS for an oral delivery of curcumin focusing on in vivo models and clinical studies. Among the 48 included studies, 3 studies were randomized controlled clinical trials, while 45 studies were animal models. To date, only five curcumin NDS have been studied in healthy volunteers: γ-cyclodextrin, phytosome, liposome, microemulsion and solid dispersion, while most curcumin NDS have been studied in animal models. Most included studies found that NDS could increase oral bioavailability of curcumin as compared to free curcumin. In conclusion, this systematic review showed evidence of the positive effect of NDS for enhancement of oral bioavailability of curcumin. EXECUTIVE SUMMARY: Curcumin is globally recognized for its health benefits, but its clinical application has been limited by its poor aqueous solubility and stability, which causes poor absorption in the gastrointestinal tract (GI tract) via oral administration. Nanocarrier-based drug delivery systems (NDS) are considered as a productive platform to solve the formulation challenge of curcumin, but evidence of such systems has not been summarized. This study aimed to systematically review current evidence of lipid and polymer-based NDS for an oral delivery of curcumin focusing on in vivo models and clinical studies. Overall, most studies found that all studied NDS could increase the absorption of curcumin as compared to free curcumin. Curcumin was rapidly absorbed and exhibited a long residence time after oral administration of curcumin NDS. In summary, this systematic review showed positive impacts of NDS for enhancement of oral absorption of curcumin.