Polymethylmethacrylate (PMMA) plates and Transpore(TM) tapes were compared as substrates for the in vitro evaluation of photostability of commercial sunscreen products. The sun care preparations were applied respectively on Transpore(TM) tapes and PMMA plates and their sun protection factors (SPF) and UVA protection parameters [UVA/UVB ratio, critical wavelength, UVA protection factor (UVA-PF)] were measured by transmission spectroscopy, before and after irradiation with simulated sunlight. No significant differences were observed in the UV protection parameters measured on Transpore(TM) tapes or PMMA plates, before exposure to the solar simulator. Conversely, after irradiation, the SPF values of the sun care products exhibited marked variations between the two substrates, the decrease in SPF being greater on PMMA plates (31.3-63.1%) than on Transpore(TM) tapes (10.4-23.8%). Differences between the two substrates were detected also for the UVA protection parameters, although they were significant only for the UVA-PF. The tested samples were assayed also by high-performance liquid chromatography (HPLC) to assess the extent of photodegradation of the UV filters present in the examined formulations. The results showed that for the PMMA plates, the light-induced decrease in SPF, as determined by spectrophotometry, fitted well with the percentage loss of ethyl hexyl methoxycinnamate (the only photounstable UVB filter present) measured by HPLC. Moreover, for the PMMA substrate, the UVA-PF percentage reduction was consistent with the percentage degradation of butyl methoxydibenzoylmethane (the only photounstable UVA filter present) determined by HPLC. On the other hand, poor correlation between spectrophotometric and HPLC analyses was observed on Transpore(TM) tapes. Therefore, PMMA plates are more reliable than Transpore(TM) tapes as substrates for in vitro photodegradation tests of sunscreen products by transmission spectroscopy.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1111/j.1468-2494.2009.00536.x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The impact of customized surface topography and porosity created by additive manufacturing technology on gingival fibroblasts.
J Prosthodont
January 2025
Prosthodontist, Implant Dentistry Associates of Arlington, Arlington, Texas, USA.
Purpose: The purpose of this study was to analyze gingival fibroblast proliferation on additively manufactured polymethylmethacrylate (PMMA) groups with different surface characteristics namely no treatment group (NTG) and customized 250 µm diameter porosity (AM-250G) group.
Materials And Methods: 3D-printed NTG was compared for its influence on growth of cells to a additively manufactured surface with porosity (AM-250G). For each group (NTG, AM-250G) 20 samples of material were tested.
Research Progress on Quantum Dot-Embedded Polymer Films and Plates for LCD Backlight Display.
Polymers (Basel)
January 2025
College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China.
Quantum dot-polymer composites have the advantages of high luminescent quantum yield (PLQY), narrow emission half-peak full width (FWHM), and tunable emission spectra, and have broad application prospects in display and lighting fields. Research on quantum dots embedded in polymer films and plates has made great progress in both synthesis technology and optical properties. However, due to the shortcomings of quantum dots, such as cadmium selenide (CdSe), indium phosphide (InP), lead halide perovskite (LHP), poor water, oxygen, and light stability, and incapacity for large-scale synthesis, their practical application is still restricted.
View Article and Find Full Text PDFInchworm Robots Utilizing Friction Changes in Magnetorheological Elastomer Footpads Under Magnetic Field Influence.
Micromachines (Basel)
December 2024
Department of Mechanical Engineering, Inha University, Incheon 22212, Republic of Korea.
The application of smart materials in robots has attracted considerable research attention. This study developed an inchworm robot that integrates smart materials and a bionic design, using the unique properties of magnetorheological elastomers (MREs) to improve the performance of robots in complex environments, as well as their adaptability and movement efficiency. This research stems from solving the problem of the insufficient adaptability of traditional bionic robots on different surfaces.
View Article and Find Full Text PDFAn unexpected cause of intractable dysphagia after 20 years following cervical spine instrumentation using bone cement alone: a case report.
Ann Med Surg (Lond)
December 2024
Department of Neurosurgery, Tribhuvan University Teaching Hospital, Maharajgunj, Kathmandu, Nepal.
Introduction And Importance: Postoperative dysphagia following anterior cervical discectomy fusion (ACDF) for cervical disc herniation is still poorly understood. Dysphagia after anterior spinal cervical approach is mild and transient. Here, the authors present a rare case suffering with severe progressive dysphagia for over 1 year after 20 years of ACDF due to expulsed bone cement abutting the esophagus which was successfully removed after reoperation.
View Article and Find Full Text PDFFlexible and Compact PVDF/PMMA-Based Gel Polymer Electrolytes for High-Performance Sodium Metal Batteries.
Macromol Rapid Commun
December 2024
School of Energy Science and Engineering and Jiangsu Key Laboratory of Process Enhancement and New Energy Equipment Technology, Nanjing Tech University, Nanjing, Jiangsu Province, 211816, China.
Sodium is gaining recognition as a promising alternative to lithium for battery applications, particularly in sodium metal batteries (SMBs), where the performance is critically influenced by the choice of electrolyte. Although conventional organic liquid electrolytes are widely used, they pose significant issues. Gel membrane (GM)-based electrolytes have demonstrated enhanced reliability and stability.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!