Entity

Time filter

Source Type

Toyama-shi, Japan

Sawada E.,Tokyo University of Technology | Yoshida N.,Tokyo University of Technology | Yoshida N.,Ikeda Mohando Co. | Sugiura A.,Tokyo University of Technology | And 2 more authors.
Journal of Dermatological Science | Year: 2012

Background: Although the mechanism(s) involved in the ceramide deficiency in the stratum corneum (SC) of atopic dermatitis (AD) skin is unknown, Th2 type cytokines have been reported to down-regulate ceramide levels in the epidermis. However, almost all research to date has focused on ceramide levels in the whole epidermis, not just in the SC layers alone, which are predominantly responsible for the skin barrier function. Objective: We highlighted the effects of Th1/Th2 cytokines on ceramide levels in the SC. Methods: We developed a modified system of human epidermal equivalents in which epidermis without a SC is cultured for 1 week to generate complete SC layers after which ceramides are extracted from the separated SC layers and are then quantified as per SC protein. Results: The addition of Th2 cytokines (IL-4/IL-6) at a concentration of 10. nM resulted in a marked decrease in SC ceramide levels. The reduced ceramide content in the SC was accompanied by the down-regulated expression of the genes encoding serine-palmitoyl transferase-2, acid sphingomyelinase and β-glucocerebrosidase in the epidermis. In contrast, the addition of Th1 cytokines (GM-CSF/IFN-γ/TNF-α) at concentrations of 2.5 or 10. nM resulted in a slight increase in SC ceramide levels, which were accompanied by no change or an increase in the expression of those genes encoding sphingolipid metabolic enzymes in the epidermis. Conclusion: These findings suggest that the Th2 type of inflammation evoked in AD skin is one of the essential factors involved in down-regulating the levels of ceramide in the SC. © 2012 Japanese Society for Investigative Dermatology. Source


Nishikawa M.,Hoshi University | Onuki Y.,Hoshi University | Okuno Y.,Ikeda Mohando Co. | Takayama K.,Hoshi University
Chemical and Pharmaceutical Bulletin | Year: 2011

This study investigated the relationship between the state of water and the dispersion stability of a skin cream formulation. Hydrophilic ointments treated with a high-pressure wet-type jet mill were used as model formulations. Spin-lattice relaxation times (T 1) were measured by magnetic resonance techniques to estimate the state of water in samples. A shorter T 1 relaxation time was obtained from samples with higher surfactant content, whereas the processing pressure of the jet mill and 1-week storage at 40°C did not influence the T 1 relaxation time. Observations using scanning electron microscopy (SEM) showed that coalescence occurred in samples with lower surfactant contents (1.0% by weight) following 1-week storage at 40°C. We also investigated samples prepared using a hydrophilic surfactant with a short polyethylene glycol (PEG) chain and with PEG-4000. From the change in T 1 relaxation times after removing the oil phase from samples by centrifugation, it was clarified that most of the surfactant was located on the surface of oil droplets. Furthermore, SEM observations showed that phase separation was facilitated as the PEG chain length of the surfactant shortened. Thus, a thin water layer over oil droplets is the most important factor for stabilizing their dispersion. This study provides proof-of-principle results on the contribution of the state of water to the dispersion stability of a skin cream formulation. © 2011 Pharmaceutical Society of Japan. Source


Yoshida N.,Tokyo University of Technology | Yoshida N.,Ikeda Mohando Co. | Sawada E.,Tokyo University of Technology | Imokawa G.,Tokyo University of Technology
Archives of Dermatological Research | Year: 2012

To examine factors that regulate ceramide production during keratinization of the human stratum corneum (SC), we developed a reconstructed human epidermal keratinization model in which a fresh layer of SC is newly formed within 1 week. Addition of the UDP-glucose: ceramide glucosyltransferase inhibitor 1-phenyl-2-decanoylamino-3-morpholino-1-propanol significantly diminished SC ceramide levels (expressed as μg/mg protein) with decreased glucosylceramide levels. Desipramine hydrochloride, an inhibitor of sphingomyelinase, also significantly reduced SC ceramide levels. Similarly, conduritol B epoxide, an inhibitor of β-glucocerebrosidase, significantly down-regulated SC ceramide levels and significantly increased glucosylceramide levels. These results indicate the reliability of this model to elucidate ceramide synthesis regulating factors. Using this model, we assessed the effects of the inflammatory cytokine interleukin-1α (IL-1α), several bioactive sphingolipids and all-trans retinoic acid (RA) on ceramide levels in the SC. Whereas treatment with IL-1α (at 10 nM) significantly down-regulated ceramide levels, treatment with sphingosylphosphorylcholine (at 50 μM) or sphingosine-1-phosphate (at 10 or 20 μM) distinctly up-regulated ceramide levels. Interestingly, RA (at low as 10 nM) significantly up-regulated ceramide levels without affecting the formation of the SC or levels of keratinization-related proteins in the epidermis. The increased levels of ceramide were accompanied by a significantly increased secretion of granulocyte-macrophage colony-stimulating factor as well as by a significantly down-regulated expression of acid-ceramidase at both the gene and protein levels. Taken together, our results underscore the superiority of this reconstructed human epidermal keratinization model to analyze factors that regulate ceramide synthesis, especially in human SC. © 2012 Springer-Verlag. Source


Nishikawa M.,Hoshi University | Onuki Y.,Hoshi University | Okuno Y.,Ikeda Mohando Co. | Takayama K.,Hoshi University
Drug Development and Industrial Pharmacy | Year: 2010

Background: A high-pressure wet-type jet mill is a powerful equipment used for the dispersion and emulsification of substances. In this study, we investigated its usefulness in the preparation of skin cream formulations. Method: We prepared a hydrophilic ointment base as a typical skin cream base, and then treated it with the wet-type jet mill under different conditions. Controllable factors of the wet-type jet mill included processing pressure, treatment cycle, and temperature of the treatment. Result: Treatment with the wet-type jet mill had a great impact on the rheological characteristics of the hydrophilic ointment base. The hysteresis areas and yield values of the treated ointments were significantly increased by increasing the processing pressure and temperature during the treatment. From scanning electron microscopic observations, the oil droplet size of the hydrophilic ointments decreased after treatment with the wet-type jet mill, suggesting that a decrease in oil droplet size mediates changes in the rheological characteristics. Conclusion: Because we can expect the wet-type jet mill to control the rheological characteristics of the ointment, it is a promising tool for the preparation of skin cream formulations. © Informa UK, Ltd. Source


Trademark
Ikeda Mohando Co. | Date: 2012-01-24

PHARMACEUTICAL PREPARATIONS, NAMELY, ANTI-INFLAMMATORY OINTMENTS, ANTI-ITCH OINTMENTS, ANTI-ITCH CREAM; PHARMACEUTICAL PREPARATIONS FOR SKIN CARE AND FOR TREATING SKIN DISORDERS; OIL EMULSION PAPER DRESSINGS; WAFER BAGS SOLD EMPTY FOR USE IN WRAPPING POWDERED MEDICINE TO MAKE IT EASIER TO SWALLOW; GAUZE FOR DRESSINGS; CAPSULES SOLD EMPTY FOR PHARMACEUTICALS; EYE PATCHES FOR MEDICAL PURPOSES; SURGICAL EAR BANDAGES; SANITARY PADS; ABSORBENT COTTON WOOL FOR MEDICAL PURPOSES; STICKING PLASTERS; BANDAGES FOR DRESSINGS; ANTISEPTIC LIQUID BANDAGES; BREAST-NURSING PADS; DENTAL COMPOSITE MATERIALS.

Discover hidden collaborations