Preparation and evaluation of oral self-microemulsifying drug delivery system of Chlorophyll

Objective This study was aimed at improving the water solubility and oral bioavailability of Chl by self-microemulsifying drug delivery system (Chl-SMEDDS). Methods Compatibility experiments, pseudo-ternary phase diagram and central composite design were used to optimize the formulation. The selected systems were further evaluated for physical characteristics, including particle size, zeta potential, and appearance. The stability, in vitro dispersion test, and in vivo intestinal perfusion experiments were used to evaluate the SMEDDS. Results The optimal composition of Chl-SMEDDS included: Labrafil M 1944 CS (35%), kolliphor RH 40 (46%), Transcutol HP (19%) and 60 mg/g Chl. The appearance of water emulsified Chl-SMEDDS was green and transparent. The particle size, zeta-potential, and transmission electron microscopy studies showed that spherical globules of Chl-SMEDDS with a size of about 22.82 +/- 1.29 nm and a negative surface charge of -24.21 +/- 3.45 mV were obtained. Chl-SMEDDS could remain stable at 25 degrees C and 4 degrees C for at least 6 months. The dispersion test showed that Chl-SMEDDS dispersed spontaneously to form microemulsion after disintegration of capsule shell and 90% drug dispersed in just 30 min in pH 1.2 HCl without any drug precipitation during the test period. In vivo intestinal perfusion experiment revealed that the main absorption site for Chl-SMEDDS was duodenum. Conclusions This study indicates that SMEDDS formulation could be an effective strategy for the oral administration of Chl.

Automated summary

The study aimed to enhance the water solubility and oral bioavailability of Chl through a self-microemulsifying drug delivery system (Chl-SMEDDS). The optimized formulation showed stable physical characteristics and improved drug dispersion, with the main absorption site in the duodenum, suggesting that SMEDDS could be an effective strategy for Chl oral administration.