Chemical and in vitro enzymatic stability of newly synthesized celecoxib lipophilic and hydrophilic amides
摘要:
Five celecoxib (CXB) acylamide sodium salts, MP-CXB, Cy-CXB, Bz-CXB, CBz-CXB and FBz-CXB were synthesized and characterized. Two simple, fast and validated RP-HPLC methods were developed for simultaneous quantitative determination of the amides and celecoxib in aqueous and biological samples and LOD and LOQ were <= 13.6 and <= 40 ng/mL, respectively. The solubility and logP(app) of the amides, in relevant media, were determined. The chemical hydrolysis, at 60,70 and 80 degrees C, of MP-CXB was studied at GIT-relevant pH (1.2, 6.8 and 7.4) and of CY-CXB was studied at skin relative pH (5.4 and 7.4). Significant hydrolysis was observed for MP-CXB at pH 1.2 only with half-lives 28.28, 11.64 and 3.53h at 60, 70 and 80 degrees C, respectively, with extrapolated half-lives of 2060 and 443 h at 25 and 37 degrees C, respectively. The hydrolysis of all amides was studied in rat live homogenate and only Cy-CXB was hydrolyzed with half-life of 3.79 h. The hydrolysis of MP-CXB and Cy-CXB was studied in human plasma and neither was hydrolyzed. It is finally suggested that hydrophobic interactions plays a role in the binding of susceptible acylamides to the hepatic hydrolyzing enzyme since only amides with saturated hydrocarbon chains underwent hydrolysis. (C) 2011 Elsevier B.V. All rights reserved.
Chemical and in vitro enzymatic stability of newly synthesized celecoxib lipophilic and hydrophilic amides
摘要:
Five celecoxib (CXB) acylamide sodium salts, MP-CXB, Cy-CXB, Bz-CXB, CBz-CXB and FBz-CXB were synthesized and characterized. Two simple, fast and validated RP-HPLC methods were developed for simultaneous quantitative determination of the amides and celecoxib in aqueous and biological samples and LOD and LOQ were <= 13.6 and <= 40 ng/mL, respectively. The solubility and logP(app) of the amides, in relevant media, were determined. The chemical hydrolysis, at 60,70 and 80 degrees C, of MP-CXB was studied at GIT-relevant pH (1.2, 6.8 and 7.4) and of CY-CXB was studied at skin relative pH (5.4 and 7.4). Significant hydrolysis was observed for MP-CXB at pH 1.2 only with half-lives 28.28, 11.64 and 3.53h at 60, 70 and 80 degrees C, respectively, with extrapolated half-lives of 2060 and 443 h at 25 and 37 degrees C, respectively. The hydrolysis of all amides was studied in rat live homogenate and only Cy-CXB was hydrolyzed with half-life of 3.79 h. The hydrolysis of MP-CXB and Cy-CXB was studied in human plasma and neither was hydrolyzed. It is finally suggested that hydrophobic interactions plays a role in the binding of susceptible acylamides to the hepatic hydrolyzing enzyme since only amides with saturated hydrocarbon chains underwent hydrolysis. (C) 2011 Elsevier B.V. All rights reserved.