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

ABSTRACT - 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 of such topical preparations. Whereas initially the procedure involved...

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Main Authors: Wai Ling Au, Michael Skinner, Isadore Kanfer
Format: Article
Language:English
Published: Frontiers Media S.A. 2008-04-01
Series:Journal of Pharmacy & Pharmaceutical Sciences
Online Access:https://journals.library.ualberta.ca/jpps/index.php/JPPS/article/view/1323
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author Wai Ling Au
Michael Skinner
Isadore Kanfer
author_facet Wai Ling Au
Michael Skinner
Isadore Kanfer
author_sort Wai Ling Au
collection DOAJ
description ABSTRACT - 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 of such topical preparations. Whereas initially the procedure involved visual assessment of the blanching response, an instrumental procedure using a chromameter was subsequently recommended as the method of choice in such evaluations. 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 and discussed. METHODS: Human subjects (volunteers) were subjected to screening using a cream containing 0.05% clobetasol propionate, in order to identify appropriate subjects for inclusion in the study. Subsequently 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 ED50 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 and corresponded well with each other. The 90% confidence interval for the visual and chromameter data were calculated using Lock's method and when only the data obtained from 23 subjects who were identified as "detectors" (according to the 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 acceptance range for the declaration of bioequivalence.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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spelling doaj.art-2e2ff8f7519445de9ec0d0edf318df4c2023-09-02T16:39:35ZengFrontiers Media S.A.Journal of Pharmacy & Pharmaceutical Sciences1482-18262008-04-0111110.18433/J3NP48Bioequivalence assessment of topical clobetasol propionate products using visual and chromametric assessment of skin blanchingWai Ling Au0Michael Skinner1Isadore Kanfer2Faculty of Pharmacy, Rhodes UniversityBiopharmaceutics Research Institute, Rhodes UniversityFaculty of Pharmacy, Rhodes UnibversityABSTRACT - 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 of such topical preparations. Whereas initially the procedure involved visual assessment of the blanching response, an instrumental procedure using a chromameter was subsequently recommended as the method of choice in such evaluations. 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 and discussed. METHODS: Human subjects (volunteers) were subjected to screening using a cream containing 0.05% clobetasol propionate, in order to identify appropriate subjects for inclusion in the study. Subsequently 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 ED50 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 and corresponded well with each other. The 90% confidence interval for the visual and chromameter data were calculated using Lock's method and when only the data obtained from 23 subjects who were identified as "detectors" (according to the 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 acceptance range for the declaration of bioequivalence.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.https://journals.library.ualberta.ca/jpps/index.php/JPPS/article/view/1323
spellingShingle Wai Ling Au
Michael Skinner
Isadore Kanfer
Bioequivalence assessment of topical clobetasol propionate products using visual and chromametric assessment of skin blanching
Journal of Pharmacy & Pharmaceutical Sciences
title Bioequivalence assessment of topical clobetasol propionate products using visual and chromametric assessment of skin blanching
title_full Bioequivalence assessment of topical clobetasol propionate products using visual and chromametric assessment of skin blanching
title_fullStr Bioequivalence assessment of topical clobetasol propionate products using visual and chromametric assessment of skin blanching
title_full_unstemmed Bioequivalence assessment of topical clobetasol propionate products using visual and chromametric assessment of skin blanching
title_short Bioequivalence assessment of topical clobetasol propionate products using visual and chromametric assessment of skin blanching
title_sort bioequivalence assessment of topical clobetasol propionate products using visual and chromametric assessment of skin blanching
url https://journals.library.ualberta.ca/jpps/index.php/JPPS/article/view/1323
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AT isadorekanfer bioequivalenceassessmentoftopicalclobetasolpropionateproductsusingvisualandchromametricassessmentofskinblanching