Preparation, characterization and in vivo studies of amorphous solid dispersion of gambogic acid with meglumine

The aim of this study was to develop an amorphous solid dispersion system utilizing meglumine (MG) as an alkalizing matrix to improve the dissolution rate and oral bioavailability of gambogic acid (GA). Solid dispersion of GA with MG (GA/MG-SD) was fabricated <i>via</i> solvent evaporation using an equal molar of quantity of GA/MG. Physicochemical characterization was conducted through FT-IR spectral analysis, DSC thermograms, PXRD patterns, and SEM imaging, and the contact angle and dissolution profiling also were determined. Pharmacokinetic evaluation was performed in SD rats to assess bioavailability enhancement. DSC analysis indicated disappeared crystal of GA and MG as no distinct peaks were observed. This was further evidenced by PXRD analysis. The dissolution of GA from GA/MG-SD reached 76.1% after 1 h in media (pH 6.8), compared to only 22.2% for free GA. The solubility and drug dissolution rate of GA/MG-SD were significantly higher than those of free GA (<i>p</i> < 0.01), and drug dissolution behavior fit in the <i>Higuchi</i> model. Furthermore, pharmacokinetic assessment demonstrated a 2.0-fold increase in AUC_0-24 values compared to free GA, confirming improved systemic exposure. Overall, the MG-based dispersion strategy effectively transformed GA into an amorphous state with superior wettability, achieving concurrent enhancement of dissolution efficiency and oral bioavailability.