Preparation and In Vitro Evaluation of Solid Dispersions of Total Flavones of Hippophae rhamnoides L.

The purpose of this study was to enhance the dissolution of total flavones of Hippophae rhamnoides L. (TFH) by solid dispersions consisting of the drug and a polymeric carrier, poloxamer 188 (PXM). The solvent evaporation method was used to prepare solid dispersions. A 3² full-factorial design approach was used for optimization wherein the amount of solvent (X ₁) and the drug-to-polymer ratio (X ₂) were selected as independent variables and the percentage of TFH dissolved in 10 min (Q ₁₀) was selected as the dependent variable. Multiple linear regression analysis revealed that a suitable level of X ₁ and X ₂ was required for obtaining higher dissolution of TFH from PXM solid dispersions. Solid dispersions were characterized by differential scanning calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and dissolution tests. Characterization studies revealed that solid dispersion of TFH–PXM showed enhancement of TFH dissolution due to the conversion of TFH into a less crystalline and/or amorphous form. In conclusion, dissolution enhancement of TFH was obtained by preparing its solid dispersions in PXM using solvent method.