Journal ofthe Korean Chemical Society 2009, Vol. 53, No. 6 Printed in the Republic of Korea Chemometric 방법에 의 메 올/물 계에서 전이 금속 이온과 소염제 Piroxicam의 산성도 및 착체 성에 관 분광광도법 연구 Jahan B. Ghasemi* and Alireza Jalalvandf Chemistry Department, Faculty ofSciences, K. N. Toosi University of Technology, Tehran, Iran 'Department ofAnalytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran ( 2009. 7. 29; 2009. 9. 8; 2009. 10. 6) Spectrophotometric Study of Acidity and Complex Formation of Anti-Inflammatory Drug Piroxicam with Some Transition Met시 Ions in Different Methanol/Water Mixtures by Chemometric Methods Jahan B. Ghasemi* and Alireza Jalalvand' Chemistry Department, Faculty ofSciences, K. N. Toosi University of Technology, Tehran, Iran 'Department ofAnalytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran (Received July 29, 2009; Revised September 8, 2009; Accepted October 6, 2009) 요약. piroxicam (PX, 4-hydroxy-2-methyl-N-2-pridyl-2H-1, 2-benzothiazine-3-carboxadiamide-1,1- dioxide)    , Co(II), Ni(II), Cu(II), Zn(II)    (MeOH)/     25 oC, pH = 5.0 I = 0.1 M   .  SQUAD       . Fitting output   ,     ,  ,    . Co(II), Ni(II), Cu(II), Zn(II) PX       Cu(II) > Co(II) > Ni(II) - Zn(II)   .            . PX    pH        .  DATAN PX       .  validity     SPECFIT/32  .      ,        . 주제어: Piroxicam, , SQUAD, DATAN, SPECFIT/32 ABSTRACT. The complex formation of anti-inflamatory drug piroxicam (PX, 4-hydroxy-2-methyl-N-2-- pridyl-2H- 1,2-benzothiazine-3-carboxadiamide- 1,1-dioxide) with transition metal ions Co(II), Ni(II), Cu(II) and Zn(II) in methanol(MeOH)/water binary mixtures were studied by spectrophotometric method at 25 oC, constant pH = 5.0 and I = 0.1 M. The computer program SQUAD was used to extract the desired information from the spectral data. The outputs of the fitting processes were stability constants, standard deviations of the estimated stability constants, concentration distribution diagrams and spectral profiles of all species. The sequence of the stability constants of PX complexes with Co(II), Ni(II), Cu(II) and Zn(II) follow the Cu(II) > Co(II) > Ni(II) = Zn(II) order. This may be due to different geometry tendencies of these metal ions. The acidity constants of the PX were also determined under above condition from its absorption spectra at different pH values. The computer program DATAN was used for determination of acidity constants of PX. The validity of the obtained acidity constants was checked by a well known computer program SPECFIT/32. The effects of the different para- meters like solvent nature, cations characteristics on the stability and acidity constants were thoroughly discussed. Keywords: Piroxicam, Spectrophotometric, SQUAD, DATAN, SPECFIT/32 -693-