Preparation, characterization and evaluation of aspirin: benzoic acid cocrystals with enhanced pharmaceutical properties

Glibenclamide - Malonic Acid Cocrystal with an Enhanced Solubility and Bioavailability

OBJECTIVE

The objective of the work is to enhance the solubility, dissolution and pharmacokinetic properties of Glibenclamide (GLB) via cocrystallization technique. Significance: Glibenclamide (GLB) is an oral hypoglycemic agent used for treating non-insulin-dependent (type II) diabetes mellitus. It exhibits poor aqueous solubility and oral bioavailability, thereby compromising its therapeutic effect. Therefore, utilizing cocrystal approach for enhancing the solubility will modulate the physicochemical properties of GLB without altering its molecular structure.

METHODS

Cocrystal was prepared by solution crystallization method using coformer malonic acid. The cocrystal was characterized by Differential Scanning Calorimetry (DSC), Powder X-ray Diffraction (PXRD) and Fourier Transform Infrared (FT-IR) studies. The prepared cocrystal was subjected to solubility, in vitro dissolution, and pharmacokinetic studies.

RESULTS

The DSC endotherms, PXRD patterns and the FT-IR spectra of the cocrystal established the formation of a cocrystal. The formation of eutectic mixture was refuted upon comparing the DSC endotherm and PXRD pattern of the cocrystal with that of the physical mixture. GLB showed a two-fold enhancement in solubility and a significant improvement in the rate of dissolution (p < 0.05, Independent t-test) after cocrystallization. The pharmacokinetic parameters on male Sprague Drawly rats showed 1.45 enhancement in AUC _0-24 and 1.36 -fold enhancement in the C_max of GLB as compared to the pure drug.

CONCLUSION

These findings demonstrate that cocrystallization technique was able to tailor the solubility and dissolution profile of GLB leading to an enhanced pharmacokinetic property.

Engineering cocrystals of Paliperidone with enhanced solubility and dissolution characteristics

In the present study, co-crystals (CCs) of Paliperidone (PPD) with coformers like benzoic acid (BA) and P-amino benzoic acid (PABA) were synthesized and characterized to improve the physicochemical properties and dissolution rate. CCs were prepared by the solvent evaporation (SE) technique and were compared with the products formed by neat grinding (NG) and liquid assisted grinding (LAG) in their enhancement of solubility. The formation of CCs was confirmed by the IR spectroscopy, powder X-ray diffraction and thermal analysis methods. The saturation solubility studies indicate that the aqueous solubility of PPD-BA and PPD-PABA CCs was significantly improved to 1.343±0.162mg/ml and 1.964±0.452mg/ml, respectively, in comparison with the PPD solubility of 0.473mg/ml. This increase in solubility is 2.83-and 3.09-fold, respectively. PPD exhibited a poor dissolution of 37.8% in 60min, while the dissolution of the CCs improved tremendously to 96.07% and 89.65% in 60min. CCs of PPD with BA and PABA present a novel approach to overcome the solubility challenges of poorly water-soluble drug PPD.