Transdermal penetrants propylene glycol

Transdermal delivery is a case in point. The skin, particularly the stratum corneum presents a formidable barrier to diffusion. Materials used to enhance its permeability have ranged from simple solvents such as ethanol or propylene glycol to aromatic chemicals such as terpenoids. Such penetration enhancers appear to work by disrupting the lipid domains in the stratum... 

Priborsky, J., Takayama, K., Nagai, T., Waitzova, D., and Elis, J. (1987). Combination effect of penetration enhancers and propylene glycol on in vitro transdermal absorption of insulin. Drug. Des. Deliv., 2 91-97. 

Perfusion of skin with transdermal-penetration-enhancing agents such as ethanol, DMSO-ds and propylene glycol was studied by in vitro P NMR [39]. Epidermal strips from abdominal pig skin were placed in a 10 mm O.D. NMR tube modified for continuous perfusion with buffered salt solution and a serial spectra were recorded on a Broker AMX500 spectrometer. Signal intensities for phosphomono- and di-esters PME and PDE, phosphocreatine PCr, inorganic phosphate Pi and nucleotide triphosphorate, >3-NTP were followed in time. Additional spectra were recorded when the perfusion medium contained dexamethasone. The dexamethasone perfusion resulted in a dose-dependent decrease in PCr and NTP levels and had an effect on PME metabolism. 

The cosmetics and transdermal drug delivery fields are also expected to further benefit from the formulation of microemulsions from mild sugarbased surfactants. Lehmann et al. have studied the effect of such a microemulsion on dermal and corneal irritation, and hydrocortisone incorporation [105]. A microemulsion containing commercially available sucrose esters, isopropyl myristate, and propylene glycol and water was prepared as a water continuous system, and 16.5% hydrocortisone was loaded into the anhydrous base mixture. The formulation spread well on the skin due to the low surface tension of the system at 26 mN/m. While the microemulsion provided greater drug penetration, it also resulted in irritation and barrier compromise. The authors make the point that the formulation may be better suited to drugs that do not induce an irritation themselves. 

Uses Emollient, emulsion stabilizer, solubilizer, superfatting agent, penetrant, solvent, pigment suspending agent In cosmetics, personal care prods., pharmaceuticals, lipsticks, sunscreens, antiperspirants, bath oils solvent and penetrant for topical and transdermal pharmaceuticals Properties Gardner 1 max. liq. mild odor sol. in min. oil, IPA, propylene glycol misc. with fat, oil and wax mixts. sp.gr. 0.845-0.855 (15 C) vise. 24-32 cps acid no. 0.1 max. sapon. no. 0.3 max. hyd. no. 195-210 UseLevei 2-30%... 

---