CYCLOPENTASILOXANE

Decamethylcyclopentasiloxane, commonly known as D5 (cyclopentasiloxane) has a wide application of use across a multitude of personal care product categories. The relative volatility of D5 is one of the key properties attributed to this substance that provide for the derived performance benefits from the use of this raw material in personal care formulations. On this basis, rapid evaporative loss following use of many products comprising D5 is expected following typical use application and corresponding wear time. Studies were conducted on three key product categories containing D5 (antiperspirants, skin care products and hair care products) to characterize the amount of D5 that may be destined to 'go down the drain' following simulated typical personal care use scenarios. Marketed antiperspirants and skin care products were applied to human subjects and hair care products were applied to human hair tressesand subsequently rinsed off at designated time points representative of typical consumer cleansing and personal hygiene habits. Wash water was collected at 0, 8 and 24h (antiperspirant and hair care analysis) and additionally at 4h (skin care analysis) post product application and samples were analyzed by isotope dilution headspace gas chromatography/mass spectrometry (GC/MS) to quantify the concentration of D5 destined to be available to go down the drain in captured wash water. It is demonstrated that significant amounts of D5 in 'leave-on' application products evaporate during typical use and that the concentration of D5 available to go down the drain under such conditions of use is only a very small (negligible) fraction of that delivered immediately upon product application.

Cyclomethicone (mixture) and the specific chain length cyclic siloxanes (n = 4-7) reviewed in this safety assessment are cyclic dimethyl polysiloxane compounds. These ingredients have the skin/hair conditioning agent function in common. Minimal percutaneous absorption was associated with these ingredients and the available data do not suggest skin irritation or sensitization potential. Also, it is not likely that dermal exposure to these ingredients from cosmetics would cause significant systemic exposure. The Cosmetic Ingredient Review Expert Panel concluded that these ingredients are safe in the present practices of use and concentration.

Hypertrophic and keloid scars are common skin conditions resulting from abnormal wound healing. They can cause itching, pain and have a negative physical and psychological impact on patients' lives. Different approaches are used aiming to improve these scars, including intralesional corticosteroids, surgery and more recently, laser therapy. Since laser therapy is expensive and may have adverse effects, it is critical to evaluate the potential benefits and harms of this therapy for treating hypertrophic and keloid scars. To assess the effects of laser therapy for treating hypertrophic and keloid scars. In March 2021 we searched the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL EBSCO Plus and LILACS. To identify additional studies, we also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses, and health technology reports. There were no restrictions with respect to language, date of publication, or study setting. We included randomised controlled trials (RCTs) for treating hypertrophic or keloid scars (or both), comparing laser therapy with placebo, no intervention or another intervention. Two review authors independently selected studies, extracted the data, assessed the risk of bias of included studies and carried out GRADE assessments to assess the certainty of evidence. A third review author arbitrated if there were disagreements. We included 15 RCTs, involving 604 participants (children and adults) with study sample sizes ranging from 10 to 120 participants (mean 40.27). Where studies randomised different parts of the same scar, each scar segment was the unit of analysis (906 scar segments). The length of participant follow-up varied from 12 weeks to 12 months. All included trials had a high risk of bias for at least one domain: all studies were deemed at high risk of bias due to lack of blinding of participants and personnel. The variability of intervention types, controls, follow-up periods and limitations with report data meant we pooled data for one comparison (and only two outcomes within this). Several review secondary outcomes - cosmesis, tolerance, preference for different modes of treatment, adherence, and change in quality of life - were not reported in any of the included studies. Laser versus no treatment: We found low-certainty evidence suggesting there may be more hypertrophic and keloid scar improvement (that is scars are less severe) in 585-nm pulsed-dye laser (PDL) -treated scars compared with no treatment (risk ratio (RR) 1.96; 95% confidence interval (CI): 1.11 to 3.45; two studies, 60 scar segments). It is unclear whether non-ablative fractional laser (NAFL) impacts on hypertrophic scar severity when compared with no treatment (very low-certainty evidence). It is unclear whether fractional carbon dioxide (CO 2 ) laser impacts on hypertrophic and keloid scar severity compared with no treatment (very low-certainty evidence). Eight studies reported treatment-related adverse effects but did not provide enough data for further analyses. Laser versus other treatments: We are uncertain whether treatment with 585-nm PDL impacts on hypertrophic and keloid scar severity compared with intralesional corticosteroid triamcinolone acetonide (TAC), intralesional Fluorouracil (5-FU) or combined use of TAC plus 5-FU (very low-certainty evidence). It is also uncertain whether erbium laser impacts on hypertrophic scar severity when compared with TAC (very low-certainty evidence). Other comparisons included 585-nm PDL versus silicone gel sheeting, fractional CO 2 laser versus TAC and fractional CO 2 laser versus verapamil. However, the authors did not report enough data regarding the severity of scars to compare the interventions. As only very low-certainty evidence is available on treatment-related adverse effects, including pain, charring (skin burning so that the surface becomes blackened

Titanium dioxide powders are contained in a large class of colour cosmetics and sunscreen formulas. When they are used, the formation of a uniform functional powder layer on the skin is an important factor to show their functionality, such as aesthetic and UV protection. Attempts were made to extract the factors that affect the UV shielding ability of the deposited powder layer. Seven kinds of surface treatments were conducted on nano-sized titanium dioxide powder to modify the surface characteristics. Dispersion samples were prepared by mixing these powders with liquids, such as mixed solutions of cyclopentasiloxane, isododecane, coconuts alkane and dimethicone using a disperser and a bead mill. The dispersions were applied using an applicator on cellulose triacetate film, polycarbonate film and polymethyl pentene film. Laser microscope observation and micro-gloss glossmeter analysis were carried out to assess the flatness of the deposited powder layers, and the UV shielding ability was evaluated using SPF analyser. Factors whose influences on the structure and UV shielding ability of the deposited powder layer being analysed were pseudo-HLB of the powders, liquids for preparing the dispersions and material of the substrates. Higher UV shielding ability was attained when powders having pseudo-HLB at around 6 were employed independent from the kinds of liquids and substrates. Flatness of the deposited layer was found to enhance the UV shielding ability of the UV-B region, while that of the UV-A region was scarcely influenced by the flatness. Employing lower surface tension liquids for preparing the dispersions and materials exhibiting lower polar components of surface free energy as substrates tended to enhance the UV shielding ability. Surface treatments conducted on the powders in this study were found to change UV shielding ability, especially UV-B shielding ability, and the relation between pseudo-HLB and UV shielding ability was scarcely influenced by the kinds of liquids. Both surface tension of liquids and the polar component of surface free energy of substrates affected the UV shielding ability. It was suggested that pseudo-HLB calculated based on chemical structure becomes useful information to choose optimum surface treatment to make uniform powder alignment independent from the surrounding environment. Les poudres de dioxyde de titane font partie d’une grande classe de cosmétiques de couleur et de formules d’écran solaire. Lorsqu’elles sont utilisées, la formation d’une couche de poudre fonctionnelle uniforme sur la peau est un facteur important pour démontrer leur mode d’action, qu’il s’agisse de l’aspect esthétique ou de la protection contre les UV. Des tentatives ont été faites pour extraire les facteurs qui altèrent la capacité de protection contre les UV de la couche de poudre déposée. MÉTHODES: Sept types de traitements de surface ont été effectués sur une poudre de dioxyde de titane de taille nanométrique pour modifier les caractéristiques de surface. Des échantillons de dispersion ont été préparés en mélangeant ces poudres avec des liquides, tels que des mélanges de cyclopentasiloxane, d’isododécane, d’alcane de noix de coco et de diméthicone, à l’aide d’un disperseur et d’un broyeur à billes. Les dispersions ont été appliquées avec un applicateur sur un film de triacétate de cellulose, un film de polycarbonate et un film de polyméthylpentène. Une observation au microscope laser ainsi qu’une analyse au micro-glossmètre ont été faites pour évaluer la planéité des couches de poudre déposées, et la capacité de protection contre les UV a été évaluée avec un analyseur SPF (indice de pro

Post-surgical hypertrophic scar is more frequently reported in Asians. Many modalities can treat scars but there have not been any publications to define the efficacy of silicone gel plus herbal extracts for scar prevention or amelioration. 48 patients, who underwent median sternotomy were randomized and double-blinded to 2 groups to use topical silicone gel plus herbal extract gel or placebo for 6 months. Patients were treated either with topical silicone gel plus herbal extract gel or control using only placebo for 6 months. The scars were observed by experienced plastic surgeons using the Vancouver scar scale. A single tertiary care center at Khon Kaen University. 48 patients who underwent median sternotomy were enrolled in this study. All patients were aged over 18 years. All the wounds were sutured with polyglycolic 4/0 subcuticular suture material and did not receive other scar management before participating in this study. The silicone gel plus herbal extract gel (Bangkok Botanica, Bangkok, Thailand) in semi-liquid form was formulated from 15% Herbal extract (Allium Cepa extract, Centella Asiatica extract, Aloe Vera extract and Paper Mulberry extract), 50% polydemethysiloxane, 30% cyclopentasiloxane and 5% silica. The placebo gel was a composite of water, acrylate, C10-30 alkyl acrylate cross-polymer, polysorbate 20 and fragrance that was similar in color and consistency as that of the active gel and packed in the similar sealed packages. The scar was assessed using the Vancouver scar scale to determine pigmentation, vascularity, pliability and height. the study showed the silicone gel plus herbal extract gel could improve scar amelioration in height (p = 0.005) and pliability (p < 0.001) when compared to the placebo. The vascularity and pigmentation showed improvement using silicone gel plus herbal extracts but the improvement was not statistically significant. The silicone gel plus herbal extracts gel was effective for scar improvement in median sternotomy wounds.

Patch tests are highly recommended in eczema patients with eyelid involvement. Sunscreen constitutes a potential cause of eyelid or facial allergic contact dermatitis, and should be considered in patients with refractory eczema on these locations. We report a patient sensitized to several emerging allergens such as bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S), Scutellaria baicalensis extract, and propylene glycol with an eyelid dermatitis. Patch tests to the combined ingredients propylene carbonate, cyclopentasiloxane, and disteardimonium hectorite; and talc, Cl 77 491, and dimethicone/methicone copolymer were also positive. We highlight the importance of systematically patch testing with the cosmetics brought in by our patients, as well as with the individual ingredients whenever positive. The identification of emerging allergies to new compounds in cosmetics mainly depends on this practice.

Oleogels contain oil or a non-polar liquid which is gelled with an agent called an organogelator. The aim of this study was to evaluate the effects of the addition of silicone oil (cyclopentasiloxane) to the gelation process and to the properties of sorbitan monostearate (SMS)-sesame oil oleogel and compared with that of SMS-sesame oil oleogel and SMS-cyclopentasiloxane oleogel. Three different oil phases; sesame oil phase, cyclopentasiloxane phase and a mixture of cyclopentasiloxane and sesame oil, were used to prepare oleogels with SMS gelator. The critical gelling concentrations (CGC) for oleogels were determined using different concentration of SMS in a range of 5%-22% (w/w). The characterization of the developed oleogels was done using Fourier transform infrared spectroscopy (FTIR), polarized light microscope, rheometer, X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The addition of cyclopentasiloxane reduced the CGC of SMS-sesame oil oleogel from 20% to 10% (w/w). In microscopic characterization, the oleogels with a mixture of oil phases showed the longer and thicker three-dimensional gel network than that of oleogels with sesame oil and cyclopentasiloxane. FTIR studies demonstrated that this network formation was mainly due to hydrogen bonding. Rheological measurements revealed that the combination of cyclopentasiloxane and sesame oil produced strong gel with higher complex modulus values and longer linear viscoelastic region than oleogels prepared with sesame oil and cyclopentasiloxane. In addition, oleogels with the combination of the two oils had higher enthalpy (Δ H m ) and entropy (Δ S m ) thus could increase thermodynamic stability of the oleogels. Therefore, the addition of cyclopentasiloxane can improve the physical, thermal properties and stability of SMS-sesame oil oleogel, provide greater sensory profile and better product aesthetics. The developed oleogel can be a novel carrier for topical drug delivery.

Head lice infestation is a public health and social problem for almost all countries worldwide. For its treatment, insecticide and dimeticone-based solutions are currently available in the markets in many countries. We aimed to compare the efficacy of commercially available anti-head lice shampoos containing insecticide and physically effective products with different percentages of dimeticone using an in vitro technique. Head lice specimens were collected from primary school children using special plastic and metal combs. Anti-head lice products were commercially purchased and used directly. The specimens were placed one by one in 5-cm Petri dishes containing a slightly wet filter paper and were kept in a plastic cage at 28±2°C and 50%±20% relative humidity. A standardized protocol was used for testing all the products, and mortality data were obtained after 24 h. Two control tests were performed with each batch of trials. For each product and control, 10-20 head lice specimens were used, and the results were statistically analyzed. Our study demonstrated that among all the tested products, two products containing mineral oils [5.5% dimeticone & silicone (patented product) and dimeticone (no percentage mentioned in the prospectus) & cyclopentasiloxane] were found to be more effective for killing head lice in vitro. Physically effective products can be repetitively used because they are non-toxic and resistance to them is not expected. To control the infestation at a public level, the use of these products needs to be encouraged with respect to their cost price.

It is important for toxicological assessment of nanoparticles to determine the penetration of nanoparticle in skin qualitatively and quantitatively. Skin penetration of four different types of rutile titanium dioxide (TiO(2)) (T-35, 35 nm, non-coating; TC-35, 35 nm, with almina/silica/silicon coating; T-disp, 10 x 100 nm, mixture of almina coated and silicon coated particles, dispersed in cyclopentasiloxan; T-250, 250 nm, non-coating) was determined with in vitro intact, stripped, and hair-removed skin of Yucatan micropigs to study the effect of dispersion and skin conditions. The TiO(2) was suspended in a volatile silicone fluid used for cosmetics, cyclopentasiloxane, at a concentration of 10%. The suspension was applied at a dose 2 microl/cm(2) for 24 hr, followed by cyanoacrylate stripping. The Ti concentration in skin was determined by ICP-MS. T-35 and T-250 easily aggregated in suspension with a mean diameter greater than 1 microm. TC-35 and T-disp showed good dispersion properties with a mean diameter in suspension of approximately 100 nm. No penetration was observed regardless of TiO(2) type in intact and stripped skin. The concentration of Ti in skin was significantly higher when TC-35 was applied on hair-removed skin. SEM-EDS observation showed that Ti penetrated into vacant hair follicles (greater than 1 mm below the skin surface), however, it did not penetrate into dermis or viable epidermis.

Straightening is a chemical process by which excessively curly hair is straightened in an irreversible way. Generally, products are formulated as emulsions with high pH value (9.0-12.0), which, after applied on hair, cause considerable damage, making it dry and fragile. This research work evaluated the protective effect of lauryl PEG/PPG-18/18 methicone, cyclopentasiloxane (and) PEG-12 dimethicone cross-polymer, jojoba oil, and aqua (and) cystine bis-PG propyl silanetriol, as conditioning agents, on Afro-ethnic hair locks treated with thioglycolate-based straightening emulsions by protein loss, combability, and traction to rupture. Standard Afro-ethnic hair locks were prepared following a protocol for straightening emulsion application. Considering the assays performed, the addition of conditioning agents to the straightening emulsion with ammonium thioglycolate benefited the hair fiber, thus diminishing protein loss, protecting the hair thread, and improving resistance to breakage. Jojoba oil and lauryl PEG/PPG-18/18 methicone were the conditioning agents that presented the best results. Straightening emulsions with ammonium thioglycolate containing aqua (and) cystine bis-PG propyl silanetriol and cyclopentasiloxane (and) PEG-12 dimethicone cross-polymer were the ones that provided higher breakage resistance of the thread.