Effects of Oleic Acid/Propylene Glycol on Rat Abdominal Stratum Corneum: Lipid Extraction and Appearance of Propylene Glycol in the Dermis Measured by Fourier Transform Infrared/Attenuated Total Reflectance(FT-IR/ATR) Spectroscopy.

Takeuchi, Yoshikazu; Yasukawa, Hidehito; Yamaoka, Yumiko; Takahashi, Naoki; Tamura, Chizu; Morimoto, Yosuke; Fukushima, Shoji; Vasavada, Ravindra C.

doi:10.1248/cpb.41.1434

Cited by 23 publications

(18 citation statements)

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“…15 C18:1/EtOH has also shown to cause extensive lipid extraction. 51 Takeuchi et al 52 found, using IR spectroscopy, that C18:1/PG treatment of rat skin produced time dependent extraction of SC lipids. This especially would create a void volume to allow permeation of solutes during iontophoresis.…”

Section: Resultsmentioning

confidence: 99%

Synergistic Effect of lontophoresis and a Series of Fatty Acids on LHRH Permeability through Porcine Skin

Bhatia

Singh

1998

Journal of Pharmaceutical Sciences

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The effect of chemical penetration enhancers (e.g., fatty acids) in combination with iontophoresis was examined on the in vitro permeability of luteinizing hormone releasing hormone (LHRH) through porcine skin. Porcine epidermis was pretreated with either ethanol (EtOH) or 10% fatty acid/EtOH. The permeability coefficient of LHRH was significantly (p < 0.05) greater through EtOH, lauric acid/EtOH, palmitic acid/EtOH, oleic acid/EtOH, linoleic acid/EtOH, and linolenic acid/EtOH treated epidermis than the control (untreated epidermis). Iontophoresis further enhanced the permeability of LHRH (p < 0.05) through enhancer-pretreated epidermis in comparison with corresponding passive permeability. Among saturated fatty acids tested, 10% palmitic acid/iontophoresis showed the highest permeability coefficient [(59.52 +/- 2.40) x 10(-4) cm/h], which was approximately 16-fold higher than that of the control [(3.57 +/- 0.41) x 10(-4) cm/h]. Unsaturated cis-octadecenoic acids were more effective penetration enhancers when compared with octadecanoic acid. Among cis-octadecenoic acids in combination with EtOH, the greater iontophoretic permeability coefficient [(59.18 +/- 12.43) x 10(-4) cm/h] was obtained through linolenic acid treated epidermis, which was significantly greater (p < 0.05) than through saturated octadecanoic acid treated epidermis [(29.08 +/- 3.18) x 10(-4) cm/h]. Also, pretreatment of epidermis with 5% linolenic acid/propylene glycol (PG) resulted in greater (p < 0.05) iontophoretic flux of LHRH in comparison to 5% linolenic acid/EtOH. Furthermore, increases in the degree of unsaturation in octadecenoic acids did not produce corresponding increases in the degree of enhancement. Reversibility studies revealed that the postrecovery passive flux of LHRH through 5% linolenic acid in combination with EtOH or PG/iontophoresis treated epidermis was significantly (p < 0.05) reduced than the prerecovery value but could not completely recover to the baseline flux (i.e., flux of LHRH through untreated epidermis).

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Section: Resultsmentioning

confidence: 99%

Synergistic Effect of lontophoresis and a Series of Fatty Acids on LHRH Permeability through Porcine Skin

Bhatia

Singh

1998

Journal of Pharmaceutical Sciences

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“…The combined infrared spectroscopy and DSC results suggest that certain exogenously applied fatty acids can disrupt the stratum corneum lipid structure and increase motional freedom or fluidity of the lipids. 8,16) It is not clear from these results, however, whether structural differences seen among the various acids are due to their relative disrupting power or simply reflect varied uptake of these compounds by the stratum corneum. Therefore further studies need to be conducted to clarify this.…”

Section: )mentioning

confidence: 93%

“…1,2) The ability of OA to enhance percutaneous absorption has long been known. 3,7,8) It appears that the stratum corneum lipids constitute the epidermal permeability barrier, and that disruption of this stratum corneum lipid structure will put the skin barrier at risk. Recent results obtained with attenuated total reflectance infrared spectroscopy suggest that the action of OA could be due to both mechanisms, i.e., lipid fluidity and lipid phase separation.…”

Section: Ultrastructural Observationsmentioning

confidence: 99%

Examination of the Mechanism of Oleic Acid-Induced Percutaneous Penetration Enhancement: An Ultrastructural Study.

Jiang

Zhou

2003

Biological & Pharmaceutical Bulletin

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The outermost layer of mammalian skin, the stratum corneum, by virtue of its unique architecture presents a significant barrier to the transdermal delivery of drugs. Recently, biophysical, morphological, and biochemical results have indicated that the stratum corneum forms a continuous sheath of protein-enriched corneocytes embedded in an intercellular matrix enriched in nonpolar lipids that are organized as lamellar layers.1,2) Although only 10 to 15% of the stratum corneum mass is comprised of lipids, these lipids largely dictate the overall skin permeability property.3) Transdermal drug delivery promises many advantages over oral or intravenous administration, and as a consequence it would be very useful to reduce the skin barrier using physical approaches and chemical enhancers, which would reversibly remove the barrier resistance of the stratum corneun and thus allow the drug to penetrate into the viable tissue and enter the systemic circulation.There is continued interest in the development of strategies to alter the skin barrier to percutaneous absorption of compounds. Oleic acid (OA) has been studied as a skin penetration enhancer for drugs via its action primarily on stratum corneum lipid structures. Studies have shown that the modes of action of OA have generated two mechanistic scenarios, which may account for the action of this enhancer: 1) lipid fluidization; and 2) lipid phase separation. 4) Since the stratum corneum lipids constitute the primary permeability barrier of the skin and these lipids exist in the stratum corneum intercellular spaces as a highly organized lamellar bilayers, 1,5) it is reasonable to expect that OA applied to the skin would emulsify or otherwise disorganize the stratum corneum lipid lamellae and thus increase skin permeability. In the present study, we investigated the use of ruthenium tetroxide postfixation and a lanthanum tracer study to ascertain the effects of OA on the stratum corneum lipids and epidermal permeability barrier function. Experimental Protocols Male Wistar rats weighing 250-300 g were used in this study. Under general anesthesia with 4% chloral hydrate by intraperitoneal injection, the hair from the back of the animals was clipped and then shaved with an electric razor. The rats were treated on the back with 10% OA/PG-soaked cotton balls. The other group serving as a control was treated with PG-soaked cotton balls. Each was rolled gently on the skin surface for 2 h at 5-min intervals, and neither OA nor PG application produced damage to the stratum corneum. MATERIALS AND METHODS MaterialsElectron Microscopy Samples were taken from the flanks of animals for electron microscopy after either OA or PG treatment. Briefly, samples were fixed in modified Karnovsky's fixative overnight at 4°C, which contained 2% paraformaldehyde, 2% glutaraldehyde, 0.06% CaCl 2 , in 0.1 M cacodylate buffer, pH 7.4. The tissues were then washed in 0.1 M cacoylate buffer, postfixed in either 0.25% ruthenium tetroxide (RuO 4 ) in 0.1 M cacodylate for 45 min in the dark at room temp...

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“…It was observed that pH could affect the abundance of Subgroups 3, 4, 6 and 7 [38,43]. Moreover, some orders showed slight decrease in the compositional proportion in the eCO 2 treatment (Figure 2), for instance Sphingomonadales, a kind of obligate aerobe that can produce catalase [44] and convert hydrogen peroxide into water and oxygen to eliminate the negative effects of peroxide to other microbes. Therefore, we suggest that oxygen content may be altered under the eCO 2 conditions and this could lead to a decline in the relative abundance of aerobic microbes such as Sphingomonadales in the soil.…”

Section: Effects Of Elevated Co 2 On Soil Carbon and Associated Microbesmentioning

confidence: 99%

Changes of Soil Microbes Related with Carbon and Nitrogen Cycling after Long-Term CO2 Enrichment in a Typical Chinese Maize Field

et al. 2020

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Elevated atmospheric CO 2 concentration (eCO 2 ) has been the most important driving factor and characteristic of climate change. To clarify the effects of eCO 2 on the soil microbes and on the concurrent status of soil carbon and nitrogen, an experiment was conducted in a typical summer maize field based on a 10-year mini FACE (Free Air Carbon Dioxide Enrichment) system in North China. Both rhizospheric and bulk soils were collected for measurement. The soil microbial carbon (MBC), nitrogen (MBN), and soil mineral N were measured at two stages. Characteristics of microbes were assayed for both rhizospheric soil and bulk soils at the key stage. We examined the plasmid copy numbers, diversities, and community structures of bacteria (in terms of 16s rRNA), fungi (in terms of ITS-internal transcribed spacer), ammonia oxidizing bacteria (AOB) and denitrifiers including nirK, nirS, and nosZ using the Miseq sequencing technique. Results showed that under eCO 2 conditions, both MBC and MBN in rhizospheric soil were increased significantly. The quantity of ITS was increased in the eCO 2 treatment compared with that in the ambient CO 2 (aCO 2 ) treatment, while the quantity of 16s rRNA in rhizospheric soil showed decrease in the rhizospheric soil in the eCO 2 treatment. ECO 2 changed the relative abundance of microbes in terms of compositional proportion of some orders or genera particularly in the rhizospheric soil-n particular, Chaetomium increased for ITS, Subgroups 4 and 6 increased for 16s rRNA, Nitrosospira decreased for AOB, and some genera showed increase for nirS, nirK, and nosZ. Nitrate N was the main inorganic nitrogen form at the tasseling stage and both quantities of AOB and denitrifiers, as well as the nosZ/(nirS+nirK) showed an increase under eCO 2 conditions particularly in the rhizospheric soil. The Nitrosospira decreased in abundance under eCO 2 conditions in the rhizospheric soil and some genera of denitrifiers also showed differences in abundance. ECO 2 did not change the diversities of microbes significantly. In general, results suggested that 10 years of eCO 2 did affect the active component of C and N pools (such as MBC and MBN) and both the quantities and relative abundance of microbes which are involved in carbon and nitrogen cycling, possibly due to the differences in both the quantities and component of substrate for relevant microbes in the rhizospheric soils.

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Effects of Oleic Acid/Propylene Glycol on Rat Abdominal Stratum Corneum: Lipid Extraction and Appearance of Propylene Glycol in the Dermis Measured by Fourier Transform Infrared/Attenuated Total Reflectance(FT-IR/ATR) Spectroscopy.

Cited by 23 publications

References 0 publications

Synergistic Effect of lontophoresis and a Series of Fatty Acids on LHRH Permeability through Porcine Skin

Synergistic Effect of lontophoresis and a Series of Fatty Acids on LHRH Permeability through Porcine Skin

Examination of the Mechanism of Oleic Acid-Induced Percutaneous Penetration Enhancement: An Ultrastructural Study.

Changes of Soil Microbes Related with Carbon and Nitrogen Cycling after Long-Term CO2 Enrichment in a Typical Chinese Maize Field

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