Photobiology Laboratory of the Medical University of South Africa.
To assess the effect of a single application of Bi-Oil to improve stratum corneum (SC) barrier function and hydration.
Subjects: 40 female participants of varying ethnicities. Test site: test products applied to the volar forearm of all subjects.
Assessment of skin hydration with a Corneometer as the primary measure, assessment of barrier function with a Vapometer as a secondary measure. Panellists washed their forearms with soap 2 hours before measurements were taken. Baseline instrumental measurements were taken. Bi-Oil and a reference oil were then applied to separate sites on the volar forearm of all subjects. Measurements were taken again immediately after product application as well as 2 hours later, before and after wiping the products off. A control untreated site was also measured at all time points.
After immediate application, both oils reduced transepidermal water loss (TEWL) compared to the no treatment control. Increased skin capacitance values at the 2 hour pre-wipe time point indicated increased skin hydration for both oils. Two hours later, after wiping the oils from the skin’s surface, Bi-Oil showed further increased TEWL values compared to the reference oil, indicating increased moisture release and therefore increased skin hydration.
To assess the effect of twice daily application of Bi-Oil for moisturisation performance and relief of dry skin.
Subjects: 25 female Caucasian participants. Test site: test products applied to the outer, lower leg of all subjects.
Soap was used to induce dry skin over a 7 day period. Bi-Oil and a reference oil were applied twice daily. Skin assessments were made on days 1 and 3. Visual evaluations were performed by a trained visual evaluator using a 2x magnifying lamp. A control untreated site was also evaluated at all time points.
Both Bi-Oil and the reference oil improved skin dryness compared with the no treatment control. Bi-Oil was statistically superior on day 3. Significant improvements in visual appearance of skin sites treated with Bi-Oil confirmed its effectiveness in relieving dry skin.