Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1.   Pharmacodynamic properties

The active ingredients, salicylic acid and lactic acid, are well-established pharmacopoeial substances. In combination, they are routinely used in the treatment of warts, corns and calluses for their keratolytic properties.

When applied topically, and in high enough concentrations, salicylic acid acts by achieving a slow, painless destruction of the thickened stratum corneum. It softens and destroys the stratum corneum of the affected tissue by reducing the adhesiveness of the corneocytes while causing the cornified epithelium to swell, soften, macerate and finally desquamate. In the treatment of warts, a mild irritant reaction, which may render the virus more prone to immunologic stimulation or response, may add to the mechanical removal of infected cells.
The other active ingredient, lactic acid, enhances the availability of the salicylic acid from the dried collodion, in addition to having antiseptic and caustic properties.

Pharmacokinetic Properties

5.2.   Pharmacokinetic properties

Salatac Gel presents 12% salicylic acid and 4% lactic acid in an evaporative collodion-like gel which forms a cohesive and adhesive film on the skin.

The formulation is presented in a collapsible aluminium tube fitted with a special applicator nozzle allowing the formulation to be dispensed precisely to the affected areas only. This minimises the spread of the preparation onto the surrounding healthy skin, which could otherwise lead to inflammation, irritation and poor patient compliance.
The film-forming characteristics of the collodion-like gel vehicle also offer distinct advantages in clinical usage. The gel quickly forms a surface film, well before it dries completely, thereby prolonging the period during which the keratolytic solution can properly infiltrate and achieve intimate contact with the surface layers of the thickened stratum corneum.

Furthermore, even when the film appears to have dried completely, the inclusion of the non-evaporative lactic acid ensures that a proportion of the salicylic acid remains in solution within the vehicle, thus permitting continued release of the keratolytic, which may otherwise be entrapped within the collodion-like film.

Systemic absorption of salicylic acid or lactic acid after application of the recommended daily dose of one or two drops of the preparation to small, circumscribed areas is exceedingly unlikely.