Abstract

A method of determining the dissociation constants of lipophilic weak acids or bases of low aqueous solubility based oh the measurement of the pH dependency of partition coefficients is described. The measurements, although subject to the possibility of error due to the partitioning of impurities, are free from the errors of extrapolation involved in mixed solvent titrimetric or solubility methods for the determination described m the literature. Precise spectrophotometry is essential, in the method described, but this coupled with a large number of data points can lead to a precision of < ± 0.03 in pKa.The cyclohexane/water partition coefficients of 8 phenothiazines measured during the course of this work are discussed in terms of published affinity constants for plasma proteins and support the view of the hydrophobic nature of drug-binding to plasma.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.