AUTHOR=Peng Yan , Peng Ying , Zhang Wei , Zhang Siyi , Peng Huiqian , Li Zhen , Li Bo , Liu Linyi , Zhuo Linsheng , Wang Zhen , Wu Junbo , Jiang Weifan 

TITLE=Novel N-phenyl-2-(aniline) benzamide hydrochloride salt development for colon cancer therapy

JOURNAL=Frontiers in Pharmacology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2024.1452904

DOI=10.3389/fphar.2024.1452904

ISSN=1663-9812

ABSTRACT=<sec><title>Introduction</title><p><italic>N</italic>-phenyl-2-(aniline) analog <bold>N53</bold> is a previously discovered dual inhibitor of Topo I and COX-2, which exhibited significant anti-colon cancer activity <italic>in vitro</italic>, but the poor solubility and moderate anti-cancer activity <italic>in vivo</italic> hindered its further development.</p></sec><sec><title>Methods</title><p>To rectify the suboptimal drug properties of <bold>N53</bold>, a series of salt forms were developed and further evaluated through <italic>in vivo</italic> and <italic>in vitro</italic> experiments.</p></sec><sec><title>Results</title><p>The hydrochloride (<bold>N53·HCl</bold>) has a well-characterized crystal structure and its solubility reached 540.1 μg/mL, which is nearly 1,700 times higher than that of <bold>N53</bold> (0.32 μg/mL). Increasing the <bold>N53</bold> solubility consistently promotes its effective concentration, further enhancing the COX-2/Topo I inhibitory activity and the anti-tumor activity <italic>in vitro</italic> (IC<sub>50</sub> values of 2.95 ± 0.08 μM for HT29 cells, 7.99 ± 0.85 μM for RKO cells, 10.94 ± 1.30 μM for HCT116 cells), as well as the anti-proliferative and pro-apoptotic activity. Meanwhile, its oral pharmacokinetic property <italic>in vivo</italic> is also improved. The elimination half-life (T1/2) is prolonged from 10.78 to 22.29 h, the maximum plasma concentration (C<sub>max</sub>) is increased 2-fold, and the area under the plasma drug concentration-time curve (AUC<sub>0–∞</sub>) is increased 3-fold. In colon cancer xenograft mouse models, the tumor inhibition rate of <bold>N53·HCl</bold> was 53.7%, superior to that of <bold>N53</bold> (34.7%). Moreover, the results of HE staining showed that <bold>N53·HCl</bold> had no obvious toxic effects and side effects on other organs, indicating that it was safe <italic>in vivo</italic>.</p></sec><sec><title>Discussion</title><p>This study demonstrated that <bold>N53·HCl</bold> exhibits superior pharmacokinetic properties, anti-colon cancer efficacy, and safety, providing a promising drug candidate for colon cancer therapy.</p></sec>