Comparison of penetration-enhancing ability of laurocapram, N-methyl-2-pyrrolidone and dodecyl-L-pyroglutamate
- 58 Downloads
The study reports on penetration enhancers used to improve drug absorption through the skin. All experiments were carried out in permeation cellsin vitro. Insulin (2.5 mg/ml) and Brilliant Blue (50.0 mg/ml) served as model drugs. They were formulated into a 40% solution of propylene glycol with increasing concentrations ofN-methyl-2-pyrrolidone (NMP) (0.0 to 20.0%), dodecylazacycloheptan-2-one (laurocapram) and a new compound dodecyl-l-pyroglutamate (DLP; 0.0 to 0.5%). The maximum amount of insulin permeated within 24 h was almost 200 μU/ml in the case of 0.1% laurocapram, while in the case of 0.1% DLP it was approximately half of that. The optimum concentration of NMP was 12.0%. Experiments performed with Brilliant Blue showed no significant difference among formulations containing either 6.0, 12.0 or 20.0% of NMP. When NMP was omitted, flux, permeability as well as the maximum concentration estimated after 26 h reached 50% of the values obtained with NMP. The lag time was twice as long in this case in comparison with the formulations containing NMP.
KeywordsAbsorption, transdermal Brilliant Blue Dodecyl-l-pyroglutamate Insulin Laurocapram N-Methyl-2-pyrrolidone Permeability, enhancement
Unable to display preview. Download preview PDF.
- 1.Beckett AH. Possibilities and limitations of transdermal absorption. In: Brandau R, Lippold BH, eds. Dermal and transdermal absorption. Stuttgart: Wissenschaftliche Verlagsgesellschaft, 1982:154–70.Google Scholar
- 2.Zaffaroni A. Industrial development of transdermal therapeutic systems. In: Dermal and transdermal absorption. Brandau R, Lippold BH, eds. Stuttgart: Wissenschaftliche Verlagsgesellschaft, 1982:190–200.Google Scholar
- 3.Aungst BJ, Rogers NJ, Shefter E. Enhancement of naloxone penetration through human skinin vitro using fatty acids, fatty alcohols, surfactants, sulfoxides and amides. Int J Pharm 1986;33:225–34.Google Scholar
- 4.Touitou E. Transdermal delivery of anxiolytics:in vitro skin permeation of midazolam maleate and diazepam. Int J Pharm 1986;33:37–43.Google Scholar
- 7.Příborský J, Takayama K, Nagai T, Waitzová D, Elis J. Effect of penetration enhancers onin vitro transdermal absorption of insulin. Drug Design Delivery 1987;2:91–7.Google Scholar
- 8.Merritt EW, Cooper ER. Diffusion apparatus for skin penetration. J Control Rel 1964;1:161–2.Google Scholar
- 10.Hou SYE, Flynn GL. Azone enhanced permeation of the skin. Kinetic and thermodynamic determinants of hydrocortisone permeation of human hairless mouse membranes. [Abstracts]. Am Pharm Assoc, 1985;15:74.Google Scholar
- 11.Woodford R, Barry BW. Penetration enhancers and the percutaneous absorption of the drugs: an update. J Toxicol Cut Ocular Toxicol 1986;5:167–77.Google Scholar