@article {43915,
	title = {Epalrestat-cytosine cocrystal and salt structures: attempt to control E,Z -> Z,Z isomerization},
	journal = {Crystal Growth \& Design},
	volume = {17},
	year = {2017},
	month = {MAY},
	pages = {3350{\textendash}3360},
	type = {Article},
	abstract = {Cocrystallization of the anti-diabetic drug Eparlestat (EPR) with cytosine (CYT) gave EPR--CYT-H+ form I, a salt-cocrystal hybrid structure, salt hydrate (EPR--CYT-H+-H2O, 1:2:1), and non-stoichiometric solvates of EPR--CYT-H+ with EtOH/n-PrOH included in the rhombohedral symmetry voids, referred to as form II. Desolvation of EPR--CYT-H+ form II solvates resulted in an unsolvated form II of EPR--CYT-H+ which was characterized by DSC, TGA and NMR. The carboxylate{\textbullet}{\textbullet}{\textbullet}cytosinium synthon was observed in the salts structure along with the uncommon CYT-H+{\textbullet}{\textbullet}{\textbullet}H+-CYT base pairing in the structures of salt-cocrystal hybrid and salt hydrate. The crystalline forms were characterized by spectroscopic (IR, NMR), thermal (DSC, HSM, TGA), powder X-ray diffraction (PXRD) and single crystal X-ray diffraction (SC-XRD) techniques. The intent of using the salt/ salt-cocrystal forms as a means to stop the E,Z  Z,Z isomerization of EPR was not successful in photo-irradiation experiments.},
	doi = {10.1021/acs.cgd.7b00322},
	author = {Nangia, Ashwini Kumar and Battini, Swapna}
}
@article {44501,
	title = {Improved stability of tuberculosis drug fixed-dose combination using isoniazid-caffeic acid and vanillic acid cocrystal},
	journal = {Journal of Pharmaceutical Sciences},
	volume = {107},
	year = {2018},
	month = {JUN},
	pages = {1667-1679},
	abstract = {The classic fixed-dose combination (FDC) of 4 tuberculosis drugs, namely rifampicin (RIF), isoniazid (INH), pyrazinamide (PZA), and ethambutol dihydrochloride (EDH) has the twin issues of physical stability and RIF cross-reaction in the 4-FDC. The major reason for these quality issues is the interaction between RIF and INH to yield isonicotinyl hydrazone in drug tablets. Pharmaceutical cocrystals of INH with caffeic acid (CFA) (PZA + EDH + RIF + INH-CFA cocrystal) and vanillic acid (VLA) (PZA + EDH + RIF + INH-VLA cocrystal) are able to stabilize the FDC formulation compared with the reference batch (PZA + EDH + RIF + INH). Stability studies under accelerated humidity and temperature stress conditions of 40{\textdegree}C and 75\% relative humidity showed that the physical stability of the cocrystal formulation was superior by powder X-ray diffraction and scanning electron microscopy analysis, and chemical purity was analyzed by high-performance liquid chromatography. Changes in the composition and structure were monitored on samples drawn at 7, 15, 22, and 30 days of storage. FDC-INH-CFA cocrystal batch exhibited greater stability compared with FDC-INH-VLA cocrystal and FDC reference drug batches. The superior stability of INH-CFA cocrystal is attributed to the presence of stronger hydrogen bonds and cyclic O-H...O synthon in the crystal structure.},
	doi = {10.1016/j.xphs.2018.02.014},
	author = {Battini, Swapna and Mannava, M. K. Chaitanya and Nangia, Ashwini Kumar}
}
