Lipophilicity Investigations of Ibuprofen

The effect of alcohols as vehicles on the percutaneous absorption and skin retention of ibuprofen modified with l-valine alkyl esters

“…However, it is characterized by low solubility (21 mg dm À3 at 25 C in water) and relative high lipophilicity (log P is in the range of 2.41-4.00 the value depends on the measurement method) which result in its poor permeation through the skin. [14][15][16][17][18][19][20][21] Due to the acidic nature (pK a ¼ 4.4), its solubility is dependent on the pH of the environmentit increases with increasing alkalinity: it can vary from 0.024 mg cm À3 (pH ¼ 2.2) to 14.8 mg dm À3 (pH ¼ 9.2). This is closely related to the increase in the ionization degree, which in turn determines the ability of ibuprofen to penetrate the skin.…”

Chemometric study of chromatographic and computational bioactivity parameters of diphenylacetamides

“…The effect of the nature of the substituent is also in accordance with the expectations that at least the values of R M 0 were recorded in all systems in the case of derivatives with the OH group as the most polar substituent, while the strongest retention in most cases was obtained for the bromide derivative. As already stated above, the chromatographic retention constant, R M 0 , is used as a measure of the lipophilicity of the compound, while the value of the chromatographic parameter m depends to a large extent on the properties of the FIGURE 1 Structure of the investigated diphenylacetamides, where R is H (1); CH 3 (2); C 2 H 5 (3); OH (4); Cl (5); Br (6); F (7); CN (8); COOCH 3 (9); COCH 3 (10) dissolved substance and its chemical structure, and is more and more used as an alternative measure of lipophilicity. For the purpose of this confirmation, R M 0 is correlated with the parameter m. The equations of the obtained linear dependences as well as the regression coefficients r are shown in Table 3.…”

“…In addition to the partition coefficient, log P , as a standard measure of lipophilicity, the chromatographic parameters, R M 0 and m , determined by reversed‐phase thin‐layer chromatography (RPTLC) are increasingly applied as alternative criteria of lipophilicity . The reason for this is the similarity in intermolecular interactions, which determine the chromatographic and biological behavior of one molecule . In practice, C‐18 phases are usually used for this purpose, although the tendency in using other modified stationary‐phase carriers is noted in the literature …”

“…[6][7][8][9] The reason for this is the similarity in intermolecular interactions, which determine the chromatographic and biological behavior of one molecule. 10 In practice, C-18 phases are usually used for this purpose, although the tendency in using other modified stationary-phase carriers is noted in the literature. [11][12][13][14] It is a well-known fact that phenylacetamide derivatives exhibit analgesic properties.…”

Interplay of Hydropathy and Heterogeneous Diffusion in the Molecular Transport Within Lamellar Lipid Mesophases

“…Experimental values of D wat and log P were taken from Refs. [42,54,[69][70][71][72][73][74][75][76][77]. 1, and can provide a reference for researchers interested in studying the release of these drugs from lipidic mesophases.…”