Foaming activity and pK(a) of some surface active compounds

F. A Alvarez Núñez, Samuel H Yalkowsky

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

A novel method to determine the pK(a) of surface active compounds is presented. Since the ionized and unionized forms of amphiphiles have distinct surface and foaming properties, foamability as a function of pH can be used to obtain an approximate pK(a). Since foam is easily produced and measured, this method requires no specialized equipment. The foamability-pH profile is sigmoidal for both weak acids and bases, and a change of the foam activity is consistently observed in the region of their pK(a). The above relationship is confirmed using the following surface active compounds: amitriptyline, cyclohexylamine, dexverapamil, 3,5-diiodothyropropionic acid (DITPA), diphenhydramine, heptanoic acid, n-heptylamine, ibuprofen, laurylcarnitine, naphthoic acid, oleic acid and phenytoin.

Original languageEnglish (US)
Pages (from-to)193-199
Number of pages7
JournalInternational Journal of Pharmaceutics
Volume151
Issue number2
DOIs
StatePublished - May 26 1997

Fingerprint

Heptanoic Acids
Cyclohexylamines
Diphenhydramine
Amitriptyline
Surface Properties
Ibuprofen
Phenytoin
Oleic Acid
Verapamil
Equipment and Supplies
Acids
1-naphthoic acid
3,5-diiodothyropropionic acid

Keywords

  • Amphiphile
  • Foam
  • pK(a)

ASJC Scopus subject areas

  • Pharmaceutical Science

Cite this

Foaming activity and pK(a) of some surface active compounds. / Núñez, F. A Alvarez; Yalkowsky, Samuel H.

In: International Journal of Pharmaceutics, Vol. 151, No. 2, 26.05.1997, p. 193-199.

Research output: Contribution to journalArticle

@article{fe7146a235c24b458db6791aadde1fc3,
title = "Foaming activity and pK(a) of some surface active compounds",
abstract = "A novel method to determine the pK(a) of surface active compounds is presented. Since the ionized and unionized forms of amphiphiles have distinct surface and foaming properties, foamability as a function of pH can be used to obtain an approximate pK(a). Since foam is easily produced and measured, this method requires no specialized equipment. The foamability-pH profile is sigmoidal for both weak acids and bases, and a change of the foam activity is consistently observed in the region of their pK(a). The above relationship is confirmed using the following surface active compounds: amitriptyline, cyclohexylamine, dexverapamil, 3,5-diiodothyropropionic acid (DITPA), diphenhydramine, heptanoic acid, n-heptylamine, ibuprofen, laurylcarnitine, naphthoic acid, oleic acid and phenytoin.",
keywords = "Amphiphile, Foam, pK(a)",
author = "N{\'u}{\~n}ez, {F. A Alvarez} and Yalkowsky, {Samuel H}",
year = "1997",
month = "5",
day = "26",
doi = "10.1016/S0378-5173(97)04906-5",
language = "English (US)",
volume = "151",
pages = "193--199",
journal = "International Journal of Pharmaceutics",
issn = "0378-5173",
publisher = "Elsevier",
number = "2",

}

TY - JOUR

T1 - Foaming activity and pK(a) of some surface active compounds

AU - Núñez, F. A Alvarez

AU - Yalkowsky, Samuel H

PY - 1997/5/26

Y1 - 1997/5/26

N2 - A novel method to determine the pK(a) of surface active compounds is presented. Since the ionized and unionized forms of amphiphiles have distinct surface and foaming properties, foamability as a function of pH can be used to obtain an approximate pK(a). Since foam is easily produced and measured, this method requires no specialized equipment. The foamability-pH profile is sigmoidal for both weak acids and bases, and a change of the foam activity is consistently observed in the region of their pK(a). The above relationship is confirmed using the following surface active compounds: amitriptyline, cyclohexylamine, dexverapamil, 3,5-diiodothyropropionic acid (DITPA), diphenhydramine, heptanoic acid, n-heptylamine, ibuprofen, laurylcarnitine, naphthoic acid, oleic acid and phenytoin.

AB - A novel method to determine the pK(a) of surface active compounds is presented. Since the ionized and unionized forms of amphiphiles have distinct surface and foaming properties, foamability as a function of pH can be used to obtain an approximate pK(a). Since foam is easily produced and measured, this method requires no specialized equipment. The foamability-pH profile is sigmoidal for both weak acids and bases, and a change of the foam activity is consistently observed in the region of their pK(a). The above relationship is confirmed using the following surface active compounds: amitriptyline, cyclohexylamine, dexverapamil, 3,5-diiodothyropropionic acid (DITPA), diphenhydramine, heptanoic acid, n-heptylamine, ibuprofen, laurylcarnitine, naphthoic acid, oleic acid and phenytoin.

KW - Amphiphile

KW - Foam

KW - pK(a)

UR - http://www.scopus.com/inward/record.url?scp=0343924226&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0343924226&partnerID=8YFLogxK

U2 - 10.1016/S0378-5173(97)04906-5

DO - 10.1016/S0378-5173(97)04906-5

M3 - Article

AN - SCOPUS:0343924226

VL - 151

SP - 193

EP - 199

JO - International Journal of Pharmaceutics

JF - International Journal of Pharmaceutics

SN - 0378-5173

IS - 2

ER -