Piroksikamın pKa Değerinin Yüksek Performanslı Sıvı Kromatografisi ile Belirlenmesi

Abstract

Bu çalışmada bir nonsteroid anti-inflamatuvar ilaç olan piroksikamın ters faz sıvı kromatografi yöntemiyle farklı asetonitril-su ikili karışımlarındaki ve sudaki asidik iyonlaşma sabitleri (pKa) belirlenmiştir. Piroksikamın kromatografik davranışına hareketli fazın pH’ı ve çözücü yüzdesinin birleştirilmiş etkisini incelemek amacıyla SVEA C18 (5 μm, 150 mm x 4.6 mm) YPSK analiz kolonu ve farklı oranda asetonitril-su (%30, %35 ve %40 (h/h)) ikili karışımlarından oluşan, farklı pH değerlerine (3,13-6,18) sahip hareketli fazlar kullanılmıştır. Asidik iyonlaşma sabitleri doğrusal olmayan regresyon modeli kullanılarak tahmin edilmiştir. Piroksikamın sudaki pKa değeri mol kesri-pKa yöntemiyle hesaplanmıştır. Veriler literatürde farklı tekniklerle elde edilmiş olanlarla kıyaslanmış ve uyumlu olduğu görülmüştür.

Keywords

• pka
• Piroksikam
• Yüksek Performanslı Sıvı Kromatografisi

Determination of pKa Value of Piroxicam by High Performance Liquid Chromatography

Abstract

In this study, acid ionization constants (pKa) of piroxicam, a nonsteroidal anti-inflammatory drug, in different acetonitrile-water binary mixtures and water were determined by reverse phase liquid chromatography method. SVEA C18 (5 μm, 150 mm x 4.6 mm) HPLC analysis column and different ratios of acetonitrile-water (30%, 35%, and 40% (v/v)) binary mixtures with different pH values (3.13-6.18) were used to investigate the combined effect of pH of the mobile phase and percentage of solvent on the chromatographic behavior of piroxicam. Acidic ionization constants were estimated using a nonlinear regression model. The pKa value of piroxicam in water was calculated by the mole fraction- pKa method. The data were compared with values obtained by different techniques in the literature and were found to be compatible.

Keywords

• pka
• Piroxicam
• High Performance Liquid Chromatography

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