Formulation, Preparation, and Evaluation of Bifunctional Micelle with Glycyrrhizic Acid Containing Emodin for Toxicity Attenuation Application

Objective: To prepare GA-Emo micelles and investigate the feasibility of using GA as both a bifunctional drug and carrier. Methods: The preparation of GA-Emo micelles was accomplished via the thin-film dispersion method with GA as the carrier. Size distribution, entrapment efficiency, and drug loading were used to evaluate the characteristics of micelles. The absorption and transport properties of the micelles in Caco-2 cells were investigated, while their pharmacodynamics in mice were preliminarily studied. Results: The optimal formulation featured a GA/Emo in weight ratio of 2:1 and an encapsulation efficiency of 23.68%. The optimized GA/Emo was characterized as small uniform spheres with an average micellar size of 168.64 ± 5.69 nm, a polydispersity index of 0.17 ± 0.01, and an electrically negative surface (−35.33 ± 0.94 mV). Absorption and transport experiments with Caco-2 cells showed that the absorption of GA-Emo micelles in small intestines was mainly passive transport, amid their transport volume being significantly higher than that of Emo monomer. The intestinal wall thickness of the GAEmo micelles group was significantly lower than that of the Emo group, which meant that the colonic toxicity of the micelles was lower than unincorporated Emo. Conclusion: The advantages of GA as a bifunctional micelle carrier in formulation characters, drug release, and toxicity attenuation provide a new idea for the application of the GA of natural medicine in drug delivery for toxicity reduction.