A Spectrophotometric Method for Determining Relative SPF Values of Sunscreen Preparations

Authors

  • J H Vogelman Department of Epidemiology
  • E. Nieves The Orentreich Foundation for the Advancement of Science, New York
  • J.L. Brind The Orentreich Foundation for the Advancement of Science
  • R.A. Nash The College of Pharmacy and Allied Health Professions, St. John's University, Jamaica
  • N. Orentreich The College of Pharmacy and Allied Health Professions

Keywords:

Sunscreens, Spectrophotometric method, Relative SPF value

Abstract

A new in vi1ro method has been developed for determining relative SPF (sun protection factor) values of sunscreen preparations, prior to more formai, in vivo evaluation, and as a quality contro) procedure for testing the finished product. The SPF value is obtained by comparison of the area under the absorbancc vs wavelength curve (ultraviolet spectrogram) of the test sample with the ultraviolet spectrogram of a standard 8% homosalate preparati on of known SPF value determined at a fixed conce11- tration and celi thickness. Measurements were made with the aid of a variable wavelength spcctrophotometer fitted with an integra tor and a flow celi. Selec tion of an appropriate sample size prior to sol- vent dilution increases the precision of the assay ( ± I SPF value).

The technique permits formula adjustcment in order Lo obtain more accurate assessment of in vitro SPF values prior to clinica! testing of sunscreen preparations.

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Published

1985-03-15 — Updated on 1985-03-15

How to Cite

[1]
Vogelman, J.H., E. Nieves, J.L. BRINO, R.A. Nash and N. ORENTREICH 1985. A Spectrophotometric Method for Determining Relative SPF Values of Sunscreen Preparations . Journal of Applied Cosmetology. 3, 1 (Mar. 1985), 1–11.

Issue

Vol. 3 No. 1 (1985): Journal of Applied Cosmetology

Section

ORIGINAL ARTICLE
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