A new cocrystal of isoniazid-quercetin with hepatoprotective effect: The design, structure, and in vitro/in vivo performance evaluation.

With the purpose of overcoming the serious hepatotoxicity of antituberculosis drug isoniazid (INH), a cocrystallization strategy based on complementary advantages was implemented by choosing the hepatoprotective nutraceutical quercetin (QCT) as the cocrystal former. The strategy plays the solubility advantage of INH to improve the bioavailability of the insoluble QCT, thereby significantly enhancing the QCT's hepatoprotective effects. The optimized protective effects of QCT, in turn, feed back to INH to reduce its hepatotoxicity. Along this line, a novel INH-QCT cocrystal was successfully prepared and structurally characterized. The systematic evaluation results of the in vitro/in vivo revealed that, due to the advantage of INH's solubility, the dissolution efficiency of QCT from the cocrystal was increased 51.67-fold compared with that of coarse quercetin, and the oral bioavailability of the cocrystal in rats was enhanced by 28.91 times. As a result, the INH-QCT cocrystal almost removed INH induced serious hepatotoxicity, which has been demonstrated by the hepatotoxicity studies in rats. These findings present new opportunities for the advantageous solid forms of low-toxic antituberculosis drugs, and open new avenues against toxic side effects of drugs through the cocrystallization mean.