permeação cutânea in vitro como ferramenta auxiliar para o estudo ...

ABSTRACT
The imidazolic anti-fungals, due to their large spectrum of action and low
toxicity, are used in great number of formulations for topical and systemic use.
The dermatologic products using emulsified vehicles are effective as carriers
for antifungal medicines, and highly accepted by population. The
cetoconazol is an imidazolic compound used in great number of market
formulations, and it was the selected drug in this work, for its presence in the
reference medicine Nizoral®, a generic pharmaceutical form of emulsion for
topical use, all properly registered and in agreement with the criteria and
attributions foreseen in the Brazilian legislation. The aim of this study was to
reproduce the physical and organoleptic parameters of the reference
medicine and in simulated formulations, and to try to elucidate subjects such
as ways of medicine elaboration and incorporation, and the relationship of
these varied technological variables with the different available excipients
normally used in the preparation of emulsified pharmaceutical products.
The evaluation of the mentioned formulations was investigated by using an in
vitro skin permeation method, and in order to do this, diffusion cells was used,
so the donor compartment was filled out with two samples (2,0g and 0,2g).
The permeant-membrane used was the pig ear skins, and the receptor
solution was the phosphate buffer solution, pH 7.4, added with 10 % ethanol.
At pre-established time intervals samples of the medium were collected for
the study of cutaneous permeation. At intervals of 1, 3, 6, 12 and 24 hr, the
exposed membranes were removed, to monitor skin penetration. The
analyses were carried out by HPLC with UV detection at 225 nm wavelength,
using methanol and 0.5 % ammonium acetate solution (20:80) as mobile
phase. From the considerations and practical observations it can be
concluded that, although in accordance with the effective norms, the
generic medicines possess different behaviors, as a result of submission to
several technological variables, and these differences can compromise the
effectiveness of the product, facts that should be proven with clinic tests. It is
suggested the creation of specific quality control procedures for the semisolids,
considering the skin as having enormous potential as route for new
medicines.
Keywords: Ketoconazole; Skin absorption; In vitro study of Percutaneous
absorption; Generic medicine.