Assessment of corticosteroid-induced skin blanching: evaluation of the Minolta Chromameter CR200

Waring, Mike; Monger, L.; Hollingsbee, D.A.; Martin, Gary P.; Marriott, Christopher

doi:10.1016/0378-5173(93)90026-c

Cited by 26 publications

(20 citation statements)

References 15 publications

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“…With fl ux measurements, an EF (equation 4) for LMO of 1.5 was found by Leopold and Lippold [25] . However, this factor is rather small and the enhancing effects observed with this vehicle could not be confi rmed in the present study because of the large standard deviations as a result of the interindividual differences in erythema response [26,27] . Compared to infi nite dose conditions, percutaneous drug penetration under fi nite dose conditions is characterized by an exponential curve profi le.…”

Section: Comparison Of Infi Nite and Finite Dose Conditionscontrasting

confidence: 39%

Time of Erythema Onset after Application of Methyl Nicotinate Ointments as Response Parameter: Influence of Penetration Kinetics and Enhancing Agents

Remane¹,

Leopold²

2006

Skin Pharmacol Physiol

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The time of erythema onset may be used as a response parameter for quantification of the cutaneous erythema response induced by methyl nicotinate. The vehicles light mineral oil (LMO; test) and medium chain triglycerides (MCT; standard) were compared with regard to the pharmacodynamic response. Moreover, the influence of penetration enhancers on the time of erythema onset was investigated under zero order penetration kinetics. The enhancers dimethyl sulfoxide, diethylene glycol monoethyl ether and three different glycerides in different concentrations were added to MCT as a standard vehicle. All preparations were applied to the forearms of volunteers under infinite dose conditions at different thermodynamic drug activity levels (0.2–3.2% of the saturation level) and different drug concentrations (0.051–0.816%), respectively. Different penetration kinetics do not influence data of erythema onset, as these data are comparable to those obtained under finite dose conditions (first order penetration kinetics). With regard to the penetration enhancers, a significantly enhanced penetration of methyl nicotinate could be observed only for diethylene glycol monoethyl ether and dimethyl sulfoxide. However, no significant difference between light mineral oil and MCT could be found with regard to penetration enhancement. The time of erythema onset is an easy and efficient parameter for quantification of the pharmacodynamic response caused by nicotinates.

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Section: Comparison Of Infi Nite and Finite Dose Conditionscontrasting

confidence: 39%

Time of Erythema Onset after Application of Methyl Nicotinate Ointments as Response Parameter: Influence of Penetration Kinetics and Enhancing Agents

Remane¹,

Leopold²

2006

Skin Pharmacol Physiol

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“…Many researchers have used methods based on reflectance measurements that either give ''erythema'' and ''pigmentation'' indices based on simple calculations 9-12 or calculate tristimulus values (L*a*b* scale͒ that have been adopted by the international committee of standards as the preferred method for color measurement. 11,[13][14][15][16][17][18][19] In the latter method L* and b*, as well as combinations of the two, have been used as pigmentation parameters and a* as the erythema parameter. Recent studies have showed that in both methods what is clinically perceived as erythema and pigmentation does not correlate linearly with the calculated indices.…”

Section: Introductionmentioning

confidence: 99%

Blood stasis contributions to the perception of skin pigmentation

Stamatas

Kollias

2004

J. Biomed. Opt.

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The chromatic characteristics of skin color arise from the interactions of light (primarily absorption and scattering) with the epidermis and the dermis. The primary light absorbers in skin are hemoglobin and melanin. Most of scattering is attributed to collagen fibers and in pigmented skin to melanosomes. Traditionally skin redness is considered to arise due to locally elevated concentrations of hemoglobin, whereas skin pigmentation is attributed to melanin. In this study we attempt to understand better the contributions of these chromophores to the perceived skin color using spectral analysis of skin color reactions induced by ultraviolet (UV) irradiation or pressure. In the first experiment 12 individuals with skin phototypes III-IV were irradiated on the back using a solar simulator with doses ranging from 0.7 to 3 MED. The skin reactions were evaluated on days 1, 7, 14, and 21 after irradiation. Evaluations included diffuse reflectance spectroscopy (DRS) and clinical assessment of the erythema and the pigment reaction. Apparent concentrations of melanin, oxy-, and deoxy-hemoglobin were calculated from the absorption spectra. In the second experiment the levels of deoxy-hemoglobin of the volar forearm of ten volunteers were selectively altered by either application of a pressure cuff or by topical application of 3% H(2)O(2). Changes in skin color appearance were documented by photography, colorimetry, and DRS. In the UV exposure experiment all reactions were dose dependent. Oxy-hemoglobin values increased to a maximum on day 1, correlating well with the clinical evaluation of erythema, and then decreased exponentially to base line. Melanin showed a significant increase on day 7 and remained relatively constant for the next 3 weeks, correlating well with the clinical evaluation of pigmentation (tanning). Deoxy-hemoglobin increased slightly on day 1 and remained elevated for the next 2 weeks. Thus, deoxy-hemoglobin correlated moderately with the clinical erythema scoring on day 1 only, while it contributes significantly to what is clinically perceived as skin tanning on days 7 and 14. Application of pressure below the diastolic level increased deoxy-hemoglobin concentration as measured by DRS. This increase corresponded to a decrease of a "pigmentation" parameter (based on the L(*)a(*)b(*) scale) in a similar fashion that has been documented for increases in melanin concentration. Topical H(2)O(2) application reduced deoxy-hemoglobin levels as measured by DRS. This reduction coincided kinetically with a visible skin blanching. Application of pressure or H(2)O(2) did not significantly alter the levels of oxy-hemoglobin or melanin. In this report we present compelling evidence that deoxy-hemoglobin significantly contributes to the skin color appearance. Blood pooling, expressed as increased deoxy-hemoglobin, can contribute to what is visually perceived as pigmentation. Furthermore, we present that measurement of its contribution to the skin color appearance can only be accomplished with DRS.

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“…Currently, the FDA recommends that the degree of blanching be assessed preferably using a chromameter and/or by visual assessment (5). Several reports have been published on the use of these methods (18)(19) and whilst the chromameter is currently perceived to be the method of choice (5), claims that the use of the visual assessment technique is more accurate have been reported (20)(21)(22)(23). The visual method involves subjective assessment of the intensity of blanching at the application site in comparison to surrounding untreated skin.…”

Section: Introductionmentioning

confidence: 99%

Bioequivalence assessment of topical clobetasol propionate products using visual and chromametric assessment of skin blanching

Skinner

Kanfer

2008

J Pharm Pharm Sci

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-PURPOSE. The assessment of the degree of skin blanching following the application of a formulation containing a topical corticosteroid has been established as a surrogate method for the determination of bioequivalence. In this study, both visual and chromametric assessments have been carried out on two topical creams containing clobetasol propionate (0.05%) and the results from both methods are compared. METHODS. Human subjects (volunteers) were screened using a cream containing 0.05% clobetasol propionate, in order to identify appropriate subjects for inclusion in the study. The study was implemented according to the FDA guidance using both visual and chromameter assessment techniques. Blanching responses were assessed visually by three trained, independent observers and instrumentally using a Chromameter ® . An ED 50 of 36 min was used as the dose duration based upon data previously obtained from a pilot study using the same topical corticosteroid reference product. A visual rating scale of 0-4 and the a-scale readings from the chromameter were used. RESULTS. The visual and chromameter blanching profiles showed similar blanching responses with good correspondence. The 90% confidence intervals for the data from both methods were calculated using Locke's method. When only the data obtained from 23 subjects who were identified as "detectors" (as per FDA guidance) were used, the products fell within the bioequivalence acceptance range of 80-125% using the visual assessment method (99.3-111.6%) whereas the data using a chromameter (86.5-129.3%) were just outside the acceptance limits. However, when all subjects (n=34) were included in the calculations, both the visual (97.9-109.2) and chromameter (90.2-120.7) data fell within the bioequivalence acceptance range. CONCLUSIONS. Whereas visual data indicated bioequivalence using either data from "detectors" or data from all subjects, the chromameter data from "detectors" only indicated bioinequivalence but inclusion of all subject data fell within the acceptance range to be declared bioequivalent.

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Assessment of corticosteroid-induced skin blanching: evaluation of the Minolta Chromameter CR200

Cited by 26 publications

References 15 publications

Time of Erythema Onset after Application of Methyl Nicotinate Ointments as Response Parameter: Influence of Penetration Kinetics and Enhancing Agents

Time of Erythema Onset after Application of Methyl Nicotinate Ointments as Response Parameter: Influence of Penetration Kinetics and Enhancing Agents

Blood stasis contributions to the perception of skin pigmentation

Bioequivalence assessment of topical clobetasol propionate products using visual and chromametric assessment of skin blanching

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