Advances in the pharmaceutical research of curcumin for oral administration

Curcumin is an isolated phytopolyphenol pigment found in the Curcuma longa, commonly known as turmeric, with various pharmacological properties. It has many effects, including anti-tumour, anti-inflammatory, anti-bacterial, anti-oxidation, and hypoglycemic properties. However, due to its oral bioavailability, the use of the drug in the clinical environment is limited. Moreover, curcumin's low bioavailability is attributed to its insoluble nature, poor permeability, and inhibition of P-glycoprotein efflux and enzyme metabolism. Several new dosage forms of curcumin have been developed based on its physical properties to improve oral administration. However, the curcumin oral administration system still needs to be improved from the perspective of both research and clinical applications.