Related Experiment Video

Updated: Aug 18, 2026

A New Straightforward Method for Lipophilicity (logP) Measurement using 19F NMR Spectroscopy
09:32

A New Straightforward Method for Lipophilicity (logP) Measurement using 19F NMR Spectroscopy

Published on: January 30, 2019

Comparison of the octanol/water partition coefficients calculated by ClogP, ACDlogP and KowWin to experimentally

Stephen G Machatha1, Samuel H Yalkowsky

  • 1College of Pharmacy, The University of Arizona, 1703 E. Mabel Street, Tucson, AZ 85721-0207, USA. machatha@pharmacy.arizona.edu

International Journal of Pharmaceutics
|April 9, 2005
PubMed

More Related Videos

Characterization and Application of Passive Samplers for Monitoring of Pesticides in Water10:34

Characterization and Application of Passive Samplers for Monitoring of Pesticides in Water

Published on: August 3, 2016

Visualizing and Quantifying Pharmaceutical Compounds within Skin using Coherent Raman Scattering Imaging11:07

Visualizing and Quantifying Pharmaceutical Compounds within Skin using Coherent Raman Scattering Imaging

Published on: November 24, 2021

Related Concept Videos

Extraction: Partition and Distribution Coefficients01:14

Extraction: Partition and Distribution Coefficients

The distribution law or Nernst's distribution law is the law that governs the distribution of a solute between two immiscible solvents. This law, also known as the partition law, states that if a solute is added to the mixture of two immiscible solvents at a constant temperature, the solute is distributed between the two solvents in such a way that the ratio of solute concentrations in the solvents remains constant at equilibrium.
For extracting a solute from an aqueous phase into an organic...
Factors Affecting Dissolution: Drug pKa, Lipophilicity and GI pH01:21

Factors Affecting Dissolution: Drug pKa, Lipophilicity and GI pH

Drug absorption within the gastrointestinal (GI) tract is a complex process influenced by several critical factors, including the site pH, the drug's dissociation constant (pKa), and the drug's lipophilicity. The GI tract exhibits a pH gradient, with an acidic environment in the stomach and a more alkaline environment in the small intestine. This pH variation directly affects the ionization state of drugs.
A drug's pKa and the pH of the gastrointestinal (GI) tract play crucial roles in drug...
One-Compartment Open Model: Wagner-Nelson and Loo Riegelman Method for ka Estimation01:24

One-Compartment Open Model: Wagner-Nelson and Loo Riegelman Method for ka Estimation

This lesson introduces two critical methods in pharmacokinetics, the Wagner-Nelson and Loo-Riegelman methods, used for estimating the absorption rate constant (ka) for drugs administered via non-intravenous routes. The Wagner-Nelson method relates ka to the plasma concentration derived from the slope of a semilog percent unabsorbed time plot. However, it is limited to drugs with one-compartment kinetics and can be impacted by factors like gastrointestinal motility or enzymatic degradation.
On...
Extraction: Effects of pH00:53

Extraction: Effects of pH

Consider a neutral form of an amine, B, with a partition coefficient, K, in a liquid mixture containing organic and aqueous phases. The pH of the aqueous phase affects the charge on acidic and basic solutes, and the charged form is usually more soluble in the aqueous phase. Suppose the conjugate acid form of the amine is soluble only in the aqueous phase while the base form is soluble in both phases. Then the distribution coefficient, D, can be given as the ratio of amine concentration in the...
Two-Compartment Open Model: Extravascular Administration01:12

Two-Compartment Open Model: Extravascular Administration

The two-compartment model for extravascular administration represents a drug's absorption and distribution process. It features a central compartment, where the drug is first absorbed, and a peripheral compartment, which illustrates the drug's distribution throughout the body. The rate of change in drug concentration in the central compartment is calculated by three exponents: absorption, distribution, and elimination.
The absorption exponent (ka) indicates the speed at which the drug is...
Physical Properties of Ethers02:17

Physical Properties of Ethers

Overview
An ether molecule has a net dipole moment due to the polarity of C–O bonds. Subsequently, boiling points of ethers are lower than those of alcohols of comparable molecular weight and slightly higher than those of hydrocarbons of comparable molecular weight (Table 1).
Ethers can act as hydrogen bond acceptors, making them more water-soluble than hydrocarbons, but since ethers cannot act as hydrogen bond donors, they are much less soluble in water than alcohols. Ethers are considered...