<i>In vivo</i>Raman spectroscopy detects increased epidermal antioxidative potential with topically applied carotenoids

Lademann, Juergen; Caspers, Peter; Pol, A. van der; Richter, Heike; Patzelt, Alexa; Zastrow, L.; Darvin, Maxim E.; Sterry, Wolfram; Fluhr, Joachim W.

doi:10.1002/lapl.200810092

Cited by 109 publications

(108 citation statements)

References 22 publications

(28 reference statements)

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“…It is known that carotenoids and other lipophilic compounds such as vitamin E are delivered to the skin by blood [2,7] and sebaceous glands [47]. The transport of carotenoids via the sweat glands has been discussed by Lademann et al [48]. Hence, the uptake of vitamin C and carotenoids follows different pathways.…”

Section: Discussionmentioning

confidence: 99%

Dose-Dependent Vitamin C Uptake and Radical Scavenging Activity in Human Skin Measured with in vivo Electron Paramagnetic Resonance Spectroscopy

Lauer

Groth²,

Haag

et al. 2013

Skin Pharmacol Physiol

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Vitamin C is a potent radical scavenger and a physiological part of the antioxidant system in human skin. The aim of this study was to measure changes in the radical-scavenging activity of human skin in vivo due to supplementation with different doses of vitamin C and at different time points. Therefore, 33 volunteers were supplemented with vitamin C or placebo for 4 weeks. The skin radical-scavenging activity was measured with electron paramagnetic resonance spectroscopy. After 4 weeks, the intake of 100 mg vitamin C/day resulted in a significant increase in the radical-scavenging activity by 22%. Intake of 180 mg/day even resulted in a significant increase of 37%. No changes were found in the placebo group. A part of the study population was additionally measured after 2 weeks: in this group radical scavenging had already reached maximal activity after 2 weeks. In conclusion, orally administered vitamin C increases the radical-scavenging activity of the skin. The effect occurs fast and is enhanced with higher doses of vitamin C.

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Section: Discussionmentioning

confidence: 99%

Dose-Dependent Vitamin C Uptake and Radical Scavenging Activity in Human Skin Measured with in vivo Electron Paramagnetic Resonance Spectroscopy

Lauer

Groth²,

Haag

et al. 2013

Skin Pharmacol Physiol

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“…Confocal Raman spectroscopy has already been applied for analysis of skin hydration status [8], the effect of penetration enhancers [9] and the epidermal antioxidative potential [10,11] of skin. In vitro follow-up studies of metronidazole [12] and phospholipids [13] indicated the potential of confocal Raman microscopy for penetration experiments.…”

Section: Introductionmentioning

confidence: 99%

Towards drug quantification in human skin with confocal Raman microscopy

Franzen

Selzer

Fluhr

et al. 2013

European Journal of Pharmaceutics and Biopharmaceutics

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CitationTowards drug quantification in human skin with confocal Raman microscopy. AbstractUnderstanding the penetration behavior of drugs into human skin is a prerequisite for the rational development and evaluation of effective dermal drug delivery.The general procedure for the acquisition of quantitative drug penetration profiles in human skin is performed by sequential segmentation and extraction. Unfortunately, this technique is destructive, laborious and lacks spatial resolution. Confocal Raman microscopy bares the potential of a chemically selective, label free and nondestructive analysis. However, the acquisition of quantitative drug depth profiles within skin by Raman microscopy is impeded by imponderable signal attenuation inside the tissue.In this study, we present a chemical semi-solid matrix system simulating the optical properties of human skin. This system serves as a skin surrogate for investigation of Raman signal attenuation under controlled conditions. Caffeine was homogeneously incorporated within the skin surrogate and Raman intensity depth profiles were acquired. A mathematical algorithm describing the Raman signal attenuation within the surrogate was derived from these profiles. Human skin samples were incubated with caffeine and Raman intensity depth profiles were similarly acquired. The surrogate algorithm was successfully applied to correct the drug profiles in human skin for signal attenuation. For the first time, a mathematical algorithm was established which allows correction of Raman signal attenuation in human skin, thus facilitating reliable drug quantification in human skin by confocal Raman spectroscopy.Keywords: confocal Raman microscopy, human skin, quantitative depth profiling, dermal drug delivery, skin surrogate, Raman signal attenuation 3

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“…The increasing use of CRM to establish skin penetration profiles has led to an increasing variety of microscope configurations and sample preparation methods used therein (table 1) [3,4,13,14,15,16,17,18,19,20,21,22,23,24]. …”

Section: Introductionmentioning

confidence: 99%

How Confocal Is Confocal Raman Microspectroscopy on the Skin? Impact of Microscope Configuration and Sample Preparation on Penetration Depth Profiles

Lunter¹

2016

Skin Pharmacol Physiol

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Background/Aims: The aim of the study was to elucidate the effect of sample preparation and microscope configuration on the results of confocal Raman microspectroscopic evaluation of the penetration of a pharmaceutical active into the skin (depth profiling). Methods: Pig ear skin and a hydrophilic formulation containing procaine HCl were used as a model system. The formulation was either left on the skin during the measurement, or was wiped off or washed off prior to the analysis. The microscope configuration was varied with respect to objectives and pinholes used. Results: Sample preparation and microscope configuration had a tremendous effect on the results of depth profiling. Regarding sample preparation, the best results could be observed when the formulation was washed off the skin prior to the analysis. Concerning microscope configuration, the use of a 40 × 0.6 numerical aperture (NA) objective in combination with a 25-µm pinhole or a 100 × 1.25 NA objective in combination with a 50-µm pinhole was found to be advantageous. Conclusion: Complete removal of the sample from the skin before the analysis was found to be crucial. A thorough analysis of the suitability of the chosen microscope configuration should be performed before acquiring concentration depth profiles.

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In vivoRaman spectroscopy detects increased epidermal antioxidative potential with topically applied carotenoids

Cited by 109 publications

References 22 publications

Dose-Dependent Vitamin C Uptake and Radical Scavenging Activity in Human Skin Measured with in vivo Electron Paramagnetic Resonance Spectroscopy

Dose-Dependent Vitamin C Uptake and Radical Scavenging Activity in Human Skin Measured with in vivo Electron Paramagnetic Resonance Spectroscopy

Towards drug quantification in human skin with confocal Raman microscopy

How Confocal Is Confocal Raman Microspectroscopy on the Skin? Impact of Microscope Configuration and Sample Preparation on Penetration Depth Profiles

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