Liquisolid Technology Improves and Reduces Source-Dependent Variability in Andrographolide Dissolution from Andrographis paniculata Extracts

Background/Objectives: Andrographolide (AG), the primary diterpene of Andrographis paniculata, is classified as a BCS Class II substance, with its dissolution known to be restricted and inconsistent across various Andrographis extracts and formulations. This study aimed to implement liquisolid (LS) technology to enhance and reduce source-dependent variability in the dissolution of AG from Andrographis paniculata extracts (APEs). Methods: Ethanolic APEs from three distinct sources in Thailand were obtained using Soxhlet extraction. The AG content in the APEs varied between 14.9 and 24.1%. LS powders of APEs and pure AG were fabricated using microcrystalline cellulose and colloidal silicon dioxide as the carriers and coating materials. Their FTIR, PXRD, and SEM characteristics, flowability, and AG content were investigated. Results: All LS formulations exhibited good flowability and assay consistency. FTIR studies suggested intermolecular interactions between the α,β-unsaturated lactone ring of AG and the liquid vehicle. PXRD and SEM studies revealed the non-crystalline state of AG in LS powder, regardless of the AG source. All LS powders, regardless of the AG source, exhibited improved and similar dissolution profiles, with a similarity factor >51 under both sink and non-sink conditions. Preliminary stability assessments demonstrated that all formulated LS powders exhibited no marked physical changes over three months, regardless of the storage conditions. The percentage of AG remaining was significantly affected by storage temperature. Only LS powders stored under refrigerated conditions maintained dissolution patterns similar to those of fresh samples. Conclusions: This study offers foundational insights into LS strategies aimed at improving and reducing the source-dependent variability of herbal-extract powders.