Improved Solubility of Baclofen Using Suitable Coformers

This work presents the application of L-tartaric acid (L-TA), ascorbic acid (AA), and L-carnitine (L-CAR) as a safe and non-toxic alternative agent to enhance the aqueous solubility of baclofen (BAC). The solvent evaporation method was employed for co-crystallization in three stoichiometric ratios of the drug, coformer (1:1, 1:3, 1:5) and formulations were confirmed by X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared (FT-IR). DSC study revealed the presence of both endothermic and exothermic peaks in compounds containing AA and L-TA. With respect to the BAC, L-TA and BAC, AA, the appearance of new diffraction peaks that do not overlap with un-processed BAC may be the implication of a new structure. The intensity of some diffraction peaks disappeared or reduced significantly which may also imply the formation of a new crystal phase. The solubility of the multicomponents increased and surpassed the solubility of BAC. Overall, the new compounds show significantly higher drug solubility whereas their physical mixtures only demonstrate a marginal increase in BAC solubility. The high solubility records of BAC, AA and BAC, L-TA evidence the marked difference in solubility of the new compounds with respect to their physical mixtures. The saturation solubility of BAC, L-CAR compound did not show any improvement relative to the un-processed BAC. These findings confirm that a new crystal phase may not have been obtained during the co-crystallization of BAC and L-CAR.