Effect of chemical enhancers on the in vitro percutaneous absorption of sumatriptan succinate.
ABSTRACT The effects of percutaneous enhancers on the transdermal absorption of sumatriptan succinate were investigated by in vitro permeation studies. Pretreatment of porcine skin with ethanol (vehicle), polyethylene glycol 600, Span 20, oleic acid, R-(+)-limonene, alpha-bisabolol and 1,8-cineole (at 5% in ethanol, w/w) produced in all cases an increase in the flux of sumatriptan. The amount of sumatriptan retained in the skin was also determined. Ethanol has showed a low but significant increment on the drug transdermal flux. Treatment of the skin with alpha-bisabolol shows the same enhancer effect than ethanol. Span 20, oleic acid, and polyethylene glycol 600 have shown a moderate enhancing activity on transdermal flux of sumatriptan. R-(+)-limonene showed the greatest ability to enhance the flux of sumatriptan.
[show abstract] [hide abstract]
ABSTRACT: The purpose of this study was to investigate physicochemical characteristics and in vitro release of zidovudine from monolithic film of Eudragit RL 100 and ethyl cellulose. Films included 2.5% or 5% (w/w) zidovudine of the dry polymer weight were prepared in various ratios of polymers by solvent evaporation method from methanol/acetone solvent mixture. The release studies were carried out by vertical Franz cells (2.2 cm(2) area, 20 ml receptor fluid). Ex vivo studies were done on Wistar rat skin within the films F6 (Eudragit RL100) and F7 (Eudragit RL100/Ethylcellulose, 1:1) consisting 5% (w/w) zidovudine in comparison with the same amount of free drug. Either iontophoresis (0.1 and 0.5 mA/cm(2) direct currents, Ag/AgCl electrodes) or dimethyl sulfoxide (pretreatment of 1% and 5%, w/w, solutions) were used as enhancers. Films consisting of ethyl cellulose under the ratio of 50% (w/w) gave similar release profiles, and the highest in vitro cumulative released amount was achieved with F6 film which gave the closest results with the free drug. This result could be due to the high swelling capacity and re-crystallization inhibition effect of RL 100 polymer which also influenced the film homogenization. All the films were fitted to Higuchi release kinetics. It was also observed that both 0.5-mA/cm(2) current and 5% (w/w) dimethyl sulfoxide applications significantly increased the cumulative permeated amount of zidovudine after 8 h; however, the flux enhancement ratio was higher for 0.5-mA/cm(2) current application, especially within F6 film. Thus, it was concluded that Eudragit RL100 film (F6) could be further evaluated for the transdermal application of zidovudine.AAPS PharmSciTech 02/2009; 10(1):88-97. · 1.43 Impact Factor
Article: Effect of vehicle on diclofenac sodium permeation from new topical formulations: in vitro and in vivo studies.[show abstract] [hide abstract]
ABSTRACT: In this study the effect of vehicle on in vitro diffusion of diclofenac sodium (DS) from new different formulations such as Carbopol gel (A), Sodium lauryl sulphate cream (B) and Carbopol cream (C) was evaluated with Franz diffusion cells using hydrophilic and hydrophobic synthetic membranes. The commercial formulation Voltaren Emulgel was used as reference. Furthermore, the in vivo efficacy of topical formulations was studied in the carrageenan-induced edema and hyperalgesia, whereas the antinociceptive effect was evaluated on thermal pain threshold in rat paw. The flux of DS across hydrophilic membranes showed this rank order: Control approximately equal to C > A approximately equal to B. On the other hand, the diffusion rate of DS across hydrophobic membranes resulted in the following order: Control > B > A approximately equal to C; this suggested a lower interaction between the vehicles and these membranes. The in vivo results indicated that the prepared formulations failed in the inflammatory tests to reduce the development of edema. Nevertheless, treatment with B formulation inhibited the development of acute hyperalgesia induced by carrageenan, and elicited a significant increase in paw withdrawal latencies whereas other formulations were ineffective. The results obtained in this study suggest that Sodium lauryl sulphate cream might be useful in local pain conditions and may be an effective alternative to the presently used systemic routes.Current Drug Delivery 01/2009; 6(1):93-100.
[show abstract] [hide abstract]
ABSTRACT: Chlorhexidine digluconate (CHG) is a widely used skin antiseptic, however it poorly penetrates the skin, limiting its efficacy against microorganisms residing beneath the surface layers of skin. The aim of the current study was to improve the delivery of chlorhexidine digluconate (CHG) when used as a skin antiseptic. Chlorhexidine was applied to the surface of donor skin and its penetration and retention under different conditions was evaluated. Skin penetration studies were performed on full-thickness donor human skin using a Franz diffusion cell system. Skin was exposed to 2% (w/v) CHG in various concentrations of eucalyptus oil (EO) and 70% (v/v) isopropyl alcohol (IPA). The concentration of CHG (μg/mg of skin) was determined to a skin depth of 1500 μm by high performance liquid chromatography (HPLC). The 2% (w/v) CHG penetration into the lower layers of skin was significantly enhanced in the presence of EO. Ten percent (v/v) EO in combination with 2% (w/v) CHG in 70% (v/v) IPA significantly increased the amount of CHG which penetrated into the skin within 2 min. The delivery of CHG into the epidermis and dermis can be enhanced by combination with EO, which in turn may improve biocide contact with additional microorganisms present in the skin, thereby enhancing antisepsis.BMC Infectious Diseases 01/2010; 10:278. · 3.12 Impact Factor