Piroksikamın pKa Değerinin Yüksek Performanslı Sıvı Kromatografisi ile Belirlenmesi

Öz

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.

Anahtar Kelimeler

• 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

Kaynakça

1. Avdeef, A., Box, K. J., Comer, J. E. A., Gilges, M., Hadley, M., Hibbert, C., Patterson, W. & Tam, K. Y. (1999). PH-metric log P 11. pKa determination of water-insoluble drugs in organic solvent–water mixtures. Journal of pharmaceutical and biomedical analysis, 20(4), 631-641. doi:https://doi.org/10.1016/S0731-7085(98)00235-0.
2. Babić, S., Horvat, A. J., Pavlović, D. M., & Kaštelan-Macan, M. (2007). Determination of pKa values of active pharmaceutical ingredients. TrAC Trends in Analytical Chemistry, 26(11), 1043-1061.doi: https://doi.org/10.1016/j.trac.2007.09.004.
3. Çelebier, M., Nenni, M., Kaplan, O., Akgeyik, E., Kaynak, M. S., & Şahİn, S. (2020). Determination of the Physicochemical Properties of Piroxicam. Turkish Journal of Pharmaceutical Sciences, 17(5), 535. doi:https://doi.org/10.4274/tjps.galenos.2019.82335.
4. Demiralay, E. C., Alsancak, G., & Ozkan, S. A. (2009). Determination of pKa values of nonsteroidal antiinflammatory drug‐oxicams by RP–HPLC and their analysis in pharmaceutical dosage forms. Journal of separation science, 32(17), 2928-2936. doi:https://doi.org/10.1002/jssc.200900234.
5. Demiralay, E. Ç., Koç, D., Daldal, Y. D., & Çakır, C. (2012). Determination of chromatographic and spectrophotometric dissociation constants of some beta lactam antibiotics. Journal of pharmaceutical and biomedical analysis, 71, 139-143. doi: https://doi.org/10.1016/j.jpba.2012.06.023.
6. Gwak, H. S., Choi, J. S., & Choi, H. K. (2005). Enhanced bioavailability of piroxicam via salt formation with ethanolamines. International journal of pharmaceutics, 297(1-2), 156-161. doi:https://doi.org/10.1016/j.ijpharm.2005.03.016.
7. Ishihama, Y., Nakamura, M., Miwa, T., Kajima, T., & Asakawa, N. (2002). A rapid method for pKa determination of drugs using pressure-assisted capillary electrophoresis with photodiode array detection in drug discovery. Journal of pharmaceutical sciences, 91(4), 933-942. doi:https://doi.org/10.1002/jps.10087.
8. Moldoveanu, S. C., & David, V. (2002). Sample preparation in chromatography: Elsevier.

9. Moldoveanu, S. C., & David, V. (2013a). Chapter 1 - Basic Information about HPLC. In S. C. Moldoveanu & V. David (Eds.), Essentials in Modern HPLC Separations (pp. 1-51): Elsevier.
10. Moldoveanu, S. C., & David, V. (2013b). Chapter 7 - Mobile Phases and Their Properties. In S. C. Moldoveanu & V. David (Eds.), Essentials in Modern HPLC Separations (pp. 363-447): Elsevier.
11. Rosés, M., Canals, I., Allemann, H., Siigur, K., & Bosch, E. (1996). Retention of Ionizable Compounds on HPLC. 2. Effect of pH, Ionic Strength, and Mobile Phase Composition on the Retention of Weak Acids. Analytical Chemistry, 68(23), 4094-4100. doi: https://doi.org/10.1021/ac960105d.
12. Sezgin, B., Arli, G., & Can, N. Ö. (2021). Simultaneous HPLC-DAD determination of seven intense sweeteners in foodstuffs and pharmaceuticals using a core-shell particle column. Journal of Food Composition and Analysis, 97, 103768. doi:https://doi.org/10.1016/j.jfca.2020.103768.
13. Skoog, D. A., Holler, F. J., & Crouch, S. R. (2017). Principles of instrumental analysis: Cengage learning.
14. Snyder, L. R., Kirkland, J. J., & Dolan, J. W. (2011). Introduction to modern liquid chromatography: John Wiley & Sons.
15. Soyseven, M., Kaynak, M. S., Çelebier, M., Aboul-Enein, H. Y., & Arli, G. (2020). Development of a RP-HPLC method for simultaneous determination of reference markers used for in-situ rat intestinal permeability studies. Journal of Chromatography B, 1147, 122150. doi:https://doi.org/10.1016/j.jchromb.2020.122150.
16. Starek, M., & Krzek, J. (2009). A review of analytical techniques for determination of oxicams, nimesulide and nabumetone. Talanta, 77(3), 925-942. doi:https://doi.org/10.1016/j.talanta.2008.09.022.
17. Subirats, X., Rosés, M., & Bosch, E. (2007). On the effect of organic solvent composition on the pH of buffered HPLC mobile phases and the pKa of analytes - A review. Separation and Purification Reviews, 36(3), 231-255. doi:https://doi.org/10.1080/15422110701539129.
18. Tindall, G. W., & Dolan, J. W. (2003). Mobile-Phase Buffers, Part II-Buffer Selection and Capacity. LC GC Europe, 16, 10.