Percutaneous Absorption

Development of topical treatment for cutaneous leishmaniasis caused by Leishmania major in experimental animals

“…White soft paraffin (petrolatum) was selected as a typical oleaginous ointment base in view of its widespread use for many pharmaceutical ointments (see reference 23). The incorporation of surface-active agents, with the ability of forming oil-in-water or water-in-oil emulsions with water, has often been used for increasing drug penetration (11). Hence, an ointment base comprising white soft paraffin and the water-in-oil emulsifying agent sorbitan sesquioleate (Arlacel) (an absorption ointment base) and several ointment bases with white soft paraffin and different oil-in-water emulsifying waxes (emulsifying ointment bases) were prepared.…”

Percutaneous absorption enhancers: mechanisms and potential

“…In 1950, Malkinson and Ferguson performed the first successful study concerning percutaneous absorption in human beings, demonstrating that the skin was permeable to topically administered drugs (Barr, 1962). Idson (1975) demonstrated that the epidermic barrier was the limiting factor for the percutaneous absorption and that once the drug passed through the stratum corneum of the epidermis, its absorption was guaranteed. Currently, the study of percutaneous absorption has been a priority in the pharmaceutical research as it presentes an alternative route for drug administration, overcoming some of the disadvantages of oral administration, such as the hepatic first-pass effect, or other adverse effects (Cordeiro et al, 1997;Finnin and Morgan, 1999;Idson, 1975;Kitagawa et al, 1998).…”

“…Rothman (1954) defined percutaneous absorption as the passage of substances through the skin from one side to another, thus reaching the blood stream. According to Idson (1975), percutaneous absorption is the passage of a substance through the epidermis, dermis, blood capillaries, and/or linf channels to the blood stream. Blank (1960) stated that it wasn't necessary to have an exact definition of absorption, but that it was important to know how molecules occupied the skins surface in a determined space and time, and where they were after leaving the skins surface.…”

“…Other factors, such as the area and method, region, period of application, the age of the skin, and the use of vehicles which alter barrier function also influence percutaneous absorption. (Idson, 1975) In a parallel manner, the presence of determined compounds, which act with diverse mechanisms, can provide variations in flow, due to modifications in cellular membrane structures, diffusion coefficient alterations, the partition coefficient of the stratum corneum/vehicle, influences cutaneous water content, and can also modify superficial tension. These substances are designated modifiers, accelerators, catalisors, or simply, absorption promotors.…”

“…The catalyzing activity of ionic surfactant depend fundamentally on the destruction of membranes of which they originate, being that they have an affinity for α-proteins (keratine), and when they form complexes, provoke reversible desnaturation and filament distension. The expansion of the membrane causes the formation of cavities the loss of water bonding capacity, which results in the conversion of α-keratine to β-keratine (Idson, 1975). Sorpotdar and Zatz (1986) observed the absorption of two nonionic surfactants, polysorbates 20 and 60.…”