Crystal growth and physical characterization of picolinic acid cocrystallized with dicarboxylic acids

• Published in: Journal of crystal growth Vol. 362; pp. 252 - 258
• Main Authors: Somphon, Weenawan, Haller, Kenneth J.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2013; Elsevier
• Subjects: A1. Cocrystallization; A1. Pharmaceutical cocrystals; A1. Single crystal growth; B1. Dicarboxylic acids; B1. Organic compounds; Bioavailability; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystal growth; Dicarboxylic acids; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Growth from solutions; Materials science; Methods of crystal growth; physics of crystal growth; Oxalic acid; Pharmaceuticals; Physics; Solid-solid transitions; Solubility, segregation, and mixing; phase separation; Specific phase transitions; Succinic acid; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Tryptophan; Unit cell; A1. Single crystal growth; A1. Pharmaceutical cocrystals; B1. Dicarboxylic acids; A1. Cocrystallization; B1. Organic compounds; Crystal growth; Drugs; Stoichiometry; Dicarboxylic acids; Chemical stability; XRD; Picolinic acid; Unit cell; Metabolites; Cocrystal; Tartrates; Crystal growth from solutions; Pharmaceutical care; Adducts; Organic compounds; Hydrates; Differential scanning calorimetry; Phthalic acid; Crystallization; Solubility; Thermogravimetry; Cocrystallization; Tryptophan; Tartaric acid; Raman spectroscopy; Monocrystals; Oxalic acid; Succinic acid; Physicochemical properties
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2012.01.059

Pharmaceutical cocrystals are multicomponent materials containing an active pharmaceutical ingredient with another component in well‐defined stoichiometry within the same unit cell. Such cocrystals are important in drug design, particularly for improving physicochemical properties such as solubility, bioavailability, or chemical stability. Picolinic acid is an endogenous metabolite of tryptophan and is widely used for neuroprotective, immunological, and anti-proliferative effects within the body. In this paper we present cocrystallization experiments of a series of dicarboxylic acids, oxalic acid, succinic acid, dl-tartaric acid, pimelic acid, and phthalic acid, with picolinic acid. Characterization by FT-IR and Raman spectroscopy, DSC and TG/DTG analysis, and X-ray powder diffraction show that new compounds are formed, including a 1:1 picolinium tartrate monohydrate, a 2:1 monohydrate adduct of picolinic acid and oxalic acid, and a 2:1 picolinic acid–succinic acid monohydrate cocrystal. ► Cocrystal screening of picolinic acid with dicarboxylic acid are reported. ► Compares solvent-drop grinding and slow evaporation. ► XRD demonstrated new phases were formed. ► Vibration spectra show the existence cocrystals or salts, through strong H-bonds. ► TG/DTG and DSC show thermal stability and melting transitions of products.