Enhancing Solubility and Dissolution Rate of p-Methoxycinnamic Acid via Multicomponent Crystal Formation with Meglumine

p-Methoxycinnamic acid, a bioactive compound derived from the hydrolysis of ethyl p-methoxycinnamate found in the rhizome of Kaempferia galanga, possesses notable pharmacological activity, including analgesic, anti-inflammatory, and antidiabetic properties. However, its poor water solubility limits its effectiveness, necessitating high doses to achieve therapeutic levels. As a Biopharmaceutics Classification System (BCS) class II compound, it has low solubility but high permeability, making solubility and dissolution rate the main barriers to absorption. This study addresses these limitations by forming a multicomponent crystal with meglumine as a coformer to enhance its solubility and therapeutic potential. The multicomponent crystal was prepared in a 1:1 molar ratio using the solvent drop grinding method. Solid state characterization was performed using differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). PXRD analysis revealed new diffraction peaks, indicating the formation of a distinct crystalline phase, while FT-IR spectra confirmed molecular interactions through wavenumber shifts. SEM analysis illustrated significant morphological changes in the multicomponent crystal compared to the pure constituent. Solubility of the multicomponent crystal showed a 3.4-fold increase, and dissolution studies demonstrated a 2.6-fold enhancement in dissolution efficiency compared to pure p-methoxycinnamic acid. These results highlight the successful formation of a p-methoxycinnamic acid-meglumine multicomponent crystal, classified as a salt. This approach not only improves solubility and dissolution efficiency but also provides a practical strategy for enhancing the formulation of poorly water-soluble drugs. These improvements may lead to better clinical performance and therapeutic outcomes, making it a valuable option in pharmaceutical development.