• Archives of Pharmacal Research
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• v.24 no.3
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• pp.224-228
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• 2001

DA-5018, a recently synthesized capsaicin analog, appears to possess potent analgesic activity when administered topically. The objective of this study is to test the feasibility of the topical administration of this compound. Specifically, our goal was to identify vehicle system that permit a reasonable transdermal permeation of the compound in mice. Among the vehicles examined, isopropyl myristate (IPM) showed the largest in vitro permeability across the intact skin (83.6 ${\pm}$ 5.42${\mu}$l/$\textrm{cm}^2$/h ). However, due to the limited solubility of DA-5018 in IPM (0.53 mg/ml), the maximal flux from the IPM medium remained at only 44.3 ${\pm}2.87{\mu}$g/$\textrm{cm}^2$/hr. In order to increase the flux, addition of better solvents for DA-5018 was attempted, under the assumption that flux is the result of both solubility and permeability. Ethoxydiglycol (EG) and oleic acid (OA) were selected as examples of food solvents. The addition of IC or OA to IPM at a 1:1 volume ratio resulted in a comparable increase in the solubility of the compound (i.e., to 61.1 and 50.2 mg/ml for EG and OA, respectively). However, the addition of EG at a 1:1 volume ratio, for example, increased the flux 6.3 fold (i.e., $279{\mu}$g/$\textrm{cm}^2$/hr), while OA, at a 1:1 volume ratio, decreased the flux 5 fold (i.e., $9.26{\mu}$g/$\textrm{cm}^2$//hr). The mechanism of this discrepancy between EG and OA was investigated by measuring the permeabilty of DA-5018 across the stratum corneum-removed skin of the mouse, under the hypothesis that the viable skin layer may serve as a barrier for the permeation of lipophilic substances such as DA 5018. The permeability of DA-5018, from the medium of EG or OA, across the viable skin differed greatly for EG ($0.41{\mu}$l/$\textrm{cm}^2$/hr) and OA ($0.086{\mu}$l/$\textrm{cm}^2$/hr), suggesting that a higher permeability across the viable skin layer is needed for the second solvents. The maximum flux across the intact skin was achieved for DA-5018 when EG was added to IPM at a 1:1 volume ratio. Thus, the use of a binary system appears to be the best approach for realizing the transdermal delivery of DA-5018 at a reasonable rate.

• Archives of Pharmacal Research
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• v.20 no.1
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• pp.93-95
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• 1997

The aim of the present study was to elucidate the mechanism of action of DA-5018 and to compare it with those of capasaicin, resiniferatoxin (ultrapotent capasaicin analog), and olvanil (systemic antinociceptive agent equipotent with capasaicin developed by Proctor & Gamble) (fig.1).

• Journal of Pharmaceutical Investigation
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• v.27 no.2
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• pp.119-123
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• 1997

The physicochemical and structural properties of new capsaicin derivative, DA-5018, were examined. The reference standard of this compound was obtained by the recrystallization. A method for the determination of the dissociation constant of the compound is described. pH-solubility and distribution coefficient were determined by chromatographic method. Fundamental properties on thermal behaviors were investigated by TG, DTA and DSC. Structural analysis based on spectroscopic method coincided with the chemical structure of DA-5018. Approximate dissociation constant of the compound determined by UV spectral method was 9.35. Solubilities and partition coefficients in various pH buffer solution appeared pH-dependency. No crystal transition or further transition was found in the thermal analysis. This compound showed good stability, but pH 13 buffer and acetone made some degradative products.

• 대한임상약리학회:학술대회논문집
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• 1998.12a
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• pp.46-46
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• 1998

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.37-44
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• 1997

The Purpose of this study was to evaluate the effect of cooking methods and reheating on texture characteristics of sausage. Sausage samples were cooked(microwaving, gas-broiling and frying), reheated on day 3 and 6 after refrigeration and put to evaluation of sensory and texture characteristics. The results of sensory evaluation showed that hardness, salty taste, rancid flavor and after-taste were increased but wetness and chewiness were decreased by reheating after refrigeration. Overall acceptability was the highest when the samples were gas broiled and reheated on day 3 after refrigeration. As for the estimation of texture changes by rheometer, hardness, cohesiveness, elasticity, gum-miness and chewiness tended to increase by reheating after refrigeration. Hardness, cohesiveness, gumminess and chewiness were the highest when the samples were gas-broiled and reheated on day 3 after refrigeration.