Effect of different carriers on in vitro dissolution behavior and physicochemical characterization of glycyrrhetinic...

The effect of PEG 4000, PVP K30, poloxamer 407 and urea as carriers glycyrrhetinic acid solid dispersions (GA-SDs) on dissolution behavior and physicochemical properties were investigated. In vitro dissolution test results show that GA-SDs prepared with four different carriers have better dissolution properties compared with pure drug and corresponding physical mixtures. The enhancement effect of four carriers on dissolution rate and equilibrium solubility shows that PVP K30>PEG 4000>P 407>urea. In addition, the dissolution rate and solubility of the GA-SDs with a carrier-drug ratio of 8:1 were better than the samples of 4:1. The DSC and XRD patterns showed that crystallization of GA-SDs prepared by PVP K30 was significantly inhibited and both were transformed to amorphous. Based on FTIR detection, hydrogen-bond between carriers (PVP K30, PEG 4000 and P 407) and GA molecules were formed. SEM results showed that compared to GA-SDs prepared by the other three carriers, GA-PVP K30-SDs have a smoother surface and clearer boundary. In conclusion, the findings of this study demonstrated that the dissolution performance of the GA-SDs prepared by the solvent method is related to carrier type. The samples with PVP K30 as the carrier have the best dissolution performance.