KANSU BÜYÜKAFŞAR, EMİNE DEMİREL, CANDAN ÖZOĞUL CEMAL AKAY, TUNCER DEĞİM
Kocatepe Tıp Dergisi - 2003;4(1):31-38
Isolated perfused rabbit ear model together with full thickness human skin and PDMS membrane were used to investigate the penetration properties of naproxen and the enhancer activity of capsaicin. The effect of capsaicin was also compared with well known enhancer azone. Different amounts of chosen enhancers were applied to the skin surface before the experiment. Naproxen was chosen as a model penetrant and the quantity of penetrated naproxen was determined by HPLC. Commercially available naproxen gel formulation and an alternative formulation containing 3 % capcaisin were also studied and results were compared. Penetrations were found to be increased when the skin was treated with azone and capsaicin. In perfused rabbit ear experiments, the enhancing mode of action of capsaicin is probably due to its chemical property and lipophilicity but not due to its vasodilatory action since the amount added into the formulation was given topically to the skin and no effects were observed on the perfusion pressure. However, intraarterial injection of those compounds decreased the pressure via their vasodilator effects. The effects of capsaicin and azone on skin using microscope were also aimed to investigate in this study and treated skin samples were investigated under light and electron microscope. It was found that capsaicin caused some alterations on stratum corneum layer of the skin like azone therefore it was observed that capsaicin caused an enhanced penetration of naproxen through human skin. In conclusion capsaicin was found to be a quite capable enhancer for skin penetration of drugs like the well-known enhancer, azone. The perfused rabbit ear model is found to be useful to study transdermal uptake of drugs and it can particularly be used during preclinical development studies. Although capsaicin was found to be a good penetration enhancer, the addition of the capsaicin to the gel formulation did not provide faster penetration.
