Residential College | false |
Status | 已發表Published |
Spectrophotometric pKa determination of ionizable pharmaceuticals: resolution of molecules with weak pH-dependent spectral shift | |
Dohoda, D.; Tsinman, K.; Tsinman, O.; Wang, H.; Tam, K. Y. | |
2015-09-01 | |
Source Publication | Journal of Pharmaceutical and biomedical analysis |
ISSN | 0731-7085 |
Pages | 88-96 |
Abstract | The extent of ionization of a drug molecule at different pH values can be characterized by its pKa (acid dissociation constants). It is an important parameter in pharmaceutical development to rationalize the physiochemical and biopharmaceutical properties of the drug molecule. UV titration for pKa determination is one of the popular methods. The success of this method requires the molecule exhibiting strong pH-dependent spectral shift related to the ionization process. Depending on the proximity between the ionizable group and the chromophore, the spectral shift may not be strong enough to warrant a successful determination. In a previous study, it has been reported that a distance of three sigma bonds between the chromophore and the ionizable group was the limit for a precise pKa determination. In this work, a UV titration method for pKa determination, with a particular emphasis on molecules with weak pH-dependent spectral shift is investigated. It has been shown that the pKa values determined from this study are in good agreement with those determined using potentiometric method and literature data (R2 = 0.998). Our methodology revealed that successful pKa determination is feasible even with a separation distance of five sigma bonds between the chromophore and the ionizable group. |
Keyword | Uv Absorption Spectroscopy Ionization Pka Alternating Least Square Analysis Physiochemical Property |
DOI | 10.1016/j.jpba.2015.05.009 |
URL | View the original |
Language | 英語English |
WOS ID | WOS:000360780700014 |
The Source to Article | PB_Publication |
Scopus ID | 2-s2.0-84930226569 |
Fulltext Access | |
Citation statistics | |
Document Type | Journal article |
Collection | DEPARTMENT OF PHARMACEUTICAL SCIENCES Faculty of Health Sciences |
Corresponding Author | Tam, K. Y. |
Recommended Citation GB/T 7714 | Dohoda, D.,Tsinman, K.,Tsinman, O.,et al. Spectrophotometric pKa determination of ionizable pharmaceuticals: resolution of molecules with weak pH-dependent spectral shift[J]. Journal of Pharmaceutical and biomedical analysis, 2015, 88-96. |
APA | Dohoda, D.., Tsinman, K.., Tsinman, O.., Wang, H.., & Tam, K. Y. (2015). Spectrophotometric pKa determination of ionizable pharmaceuticals: resolution of molecules with weak pH-dependent spectral shift. Journal of Pharmaceutical and biomedical analysis, 88-96. |
MLA | Dohoda, D.,et al."Spectrophotometric pKa determination of ionizable pharmaceuticals: resolution of molecules with weak pH-dependent spectral shift".Journal of Pharmaceutical and biomedical analysis (2015):88-96. |
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