Evaluation of the Effect of Different Fatty Acids on the Percutaneous Absorption of Metaproterenol Sulfate

Abstract

The in vitro permeation rates of metaproterenol sulfate (MPS) across hairless mouse skin and TESTSKIN living skin equivalent were very low unless skin permeation enhancers were included in the vehicle. An optimum balance should be established between the chain length of the fatty acid and its molar ratio to MPS in order to enhance its penetration through the skin. Thus, the best flux values were shown by capric acid: MPS, 3:1 molar ratio, and lauric acid:MPS, 1:1 and 2:1 molar ratio, while myristic acid:MPS, 1:1 molar ratio, was the optimum under the experimental conditions used. The mechanism of the enhancing effect was examined by measuring 1H NMR spectra and the apparent partition coefficient of MPS, lauric acid, and the mixture. The apparent partition coefficient of MPS between n-octanol and water was higher for the mixture with lauric acid than for MPS alone. A 1:1 molar ratio formulation of MPS and lauric acid was selected for the in vivo permeation study. The data indicated that lauric acid increased the diffusivity of MPS in the skin by forming a complex and by affecting its partition coefficient between the skin and the delivery system.

Skin Permeation Enhancement of Diclofenac by Fatty Acids

“…This is consistent with previous reports where combining the fatty acids and PG has shown a synergistic enhancement on skin permeation rate of nicardipine (Aboofazeli et al 2002), physostigmine (Wang et al 2005) and ketoprofen (Bowen and Heard 2006). Therefore, although fatty acids have been extensively used as permeation enhancers, the choice of an optimum fatty acid depends on the drug as well as the solvent used (Aungst 1989;Elyan et al 1996;Stott et al 2001). …”

“…Fatty acids are known to enter the hydrophobic tails of the stratum corneum lipid bilayer, disturbing their packing, increasing their fluidity, and subsequently, decreasing the diffusional resistance to permeates (Golden et al 1987). The effect of varying carbon-chain lengths, degrees and types of unsaturation (position, number), the branching schema, and substituents has been reported to influence the ability of fatty acids to act as skin penetration enhancers (Elyan et al 1996;Bhatia and Singh 1998;Takeuchi et al 1998;Taguchi et al 1999). In this study, the effects of 12 fatty acids on the transdermal delivery of diclofenac in vitro have been systematically investigated.…”

Enhanced transdermal controlled delivery of glimepiride from the ethylene-vinyl acetate matrix

“…Fatty acids can differ in several features: chain length, characteristics of the double bonds (position, number, and configuration), branching schema, and substituents. These structural variations can influence their effects as skin penetration enhancers (Elyan, Sidhom, & Plakogiannis, 1996;Bhatia & Singh, 1998;Takeuchi et al, 1998;Taguchi et al, 1999). Fatty acids are capable of inserting between the hydrophobic tails of the stratum corneum lipid bilayer, thus disturbing their packing, increasing their fluidity, and, subsequently, decreasing the diffusional resistance to permeants (Golden, Mckie, & Potts, 1987).…”

Synthesis and Evaluation of Different Fatty Acid Esters Formulated into Precirol ATO-Based Lipid Nanoparticles as Vehicles for Topical Delivery

“…These structural variations can strongly influence their effects as skin penetration enhancers. [16][17][18] In our previous work, SLN based on Precirol ® ATO (PCR) was developed as carrier for econazole nitrate (ECN) and the behaviors of drug release in vitro and in vivo were studied. 19) In this context, we considered of interest to investigate the formulation of various fatty acid esters into nanoparticulate systems and evaluate the influence of the chain length on the permeation enhancement ability.…”