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PubMed2006

Final report on the safety assessment of Triethylene Glycol and PEG-4.

Triethylene Glycol and PEG-4 (polyethylene glycol) are polymers of ethylene oxide alcohol. Triethylene Glycol is a specific three-unit chain, whereas PEG-4 is a polymer with an average of four units, but may contain polymers ranging from two to eight ethylene oxide units. In the same manner, other PEG compounds, e.g., PEG-6, are mixtures and likely contain some Triethylene Glycol and PEG-4. Triethylene Glycol is a fragrance ingredient and viscosity decreasing agent in cosmetic formulations, with a maximum concentration of use of 0.08% in skin-cleansing products. Following oral doses, Triethylene Glycol and its metabolites are excreted primarily in urine, with small amounts released in feces and expired air. With oral LD50 values in rodents from 15 to 22 g/kg, this compound has little acute toxicity. Rats given short term oral doses of 3% in water showed no signs of toxicity, whereas all rats given 10% died by the 12th day of exposure. At levels up to 1 g/m3, rats exposed to aerosolized Triethylene Glycol for 6 h per day for 9 days showed no signs of toxicity. Rats fed a diet containing 4% Triethylene Glycol for 2 years showed no signs of toxicity. There were no treatment-related effects on rats exposed to supersaturated Triethylene Glycol vapor for 13 months nor in rats that consumed 0.533 cc Triethylene Glycol per day in drinking water for 13 months. Triethylene Glycol was not irritating to the skin of rabbits and produced only minimal injury to the eye. In reproductive and developmental toxicity studies in rats and mice, Triethylene Glycol did not produce biologically significant embryotoxicity or teratogenicity. However, some maternal toxicity was seen in dams given 10 ml/kg/day during gestation. Triethylene Glycol was not mutagenic or genotoxic in Ames-type assays, the Chinese hamster ovary mutation assay, and the sister chromatid exchange assays. PEG-4 is a humectant and solvent in cosmetic products, with a maximum concentration of use of 20% in the "other manicuring preparations" product category. This ingredient, with an oral LD50 in rats of 32.77 g/kg, has low acute toxicity. Rats given up to 50,000 ppm PEG-4 in drinking water for 5 days showed no permanent signs of toxicity. Rats given daily oral doses up to 2 g/kg/day of PEG-4 for 33 days showed no signs of toxicity. Undiluted PEG-4 produced only minimal injury to the rabbit eye. PEG-4 was not mutagenic in Ames-type assays, did not induce chromosome aberration in an in vivo bone marrow assay, and was negative for genotoxicity in a dominant lethal assay using rats. Other PEG compounds, which have previously been reviewed by the Cosmetic Ingredient Review (CIR) Expert Panel, e.g., PEG-6, are mixtures that likely include Triethylene Glycol and PEG-4, so these data were also considered. PEG-6 and PEG-8 were not dermal irritants in several rabbit studies. PEG-2 Stearate had a potential for slight irritation in rabbits but was not a sensitizer in guinea pigs. PEG-2 Cocamine was a moderate irritant in rabbits, producing severe erythema. In one dermal study, PEG-2 Cocamine was determined to be corrosive to rabbit skin, causing eschar and necrosis. PEG-6 and PEG-8 caused little to no ocular irritation. PEG-8 was not mutagenic or genotoxic in a Chinese hamster ovary assay, a sister-chromatid exchange assay, and in an unscheduled DNA synthesis assay. In clinical studies on normal skin, PEG-6 and PEG-8 caused mild cases of immediate hypersensitivity; PEG-8 was not a sensitizer; PEG-2 Stearate was not an irritant, a sensitizer, or a photosensitizer; and PEG-6 Stearate was not an irritant or sensitizer. In damaged skin, cases of systemic toxicity and contact dermatitis in burn patients were attributed to a PEG-based topical ointment. The CIR Expert Panel acknowledged the lack of dermal sensitization data for Triethylene Glycol and dermal irritation and sensitization data for PEG-4. That PEG-6, PEG-8, and PEG-2 Stearate were not irritants or sensitizers suggested that Triethylene Glycol and PEG-4 also would not be irritants or sensitizers, and the absence of any reported reactions in the case literature and the professional experience of the Expert Panel further supported the absence of any significant sensitization potential. The need for additional data to demonstrate the safety of PEGs Cocamine was related to the Cocamine moiety and is not relevant here. The Panel reminded formulators of cosmetic products that, as with other PEG compounds, Triethylene Glycol and PEG-4 should not be used on damaged skin because of cases of systemic toxicity and contact dermatitis in burn patients have been attributed to a PEG-based topical ointment. Based on its consideration of the available information, the CIR Expert Panel concluded that Triethylene Glycol and PEG-4 are safe as cosmetic ingredients in the present practices and concentrations of use as described in this safety assessment.

Animals↗
PubMed1997

Complications of motility peg placement for the hydroxyapatite orbital implant.

PURPOSE: The hydroxyapatite implant is an ocular motility implant designed to provide natural movement of the artificial eye. The movement of the prosthesis is maximized when the implant is coupled to the prosthesis via a peg. The purpose of this study is to determine the complications of the hydroxyapatite motility peg and the factors related to those complications. DESIGN: Retrospective review of 47 cases over 5 years. METHODS: A retrospective review was performed on all cases of hydroxyapatite motility peg placement. The technique of hydroxyapatite and peg placement, follow-up details, and complications of the peg were recorded. RESULTS: The complications of peg placement included peg extrusion in 26% (12 of 47), nonspecific conjunctivitis in 6% (3 of 47), audible click in 6% (3 of 47), temporary excessive conjunctival edema in 4% (2 of 47), and temporary excessive postoperative pain in 4% (2 of 47). There were no cases of infection, persistent pain, persistent edema, or discharge at peg site. The median time interval from peg placement to extrusion was 16 months (range, 1-52 months). The only statistically significant factor related to peg extrusion was age over 50 years (P = 0.04). There was a trend toward peg extrusion with use of a nonsleeved peg (versus sleeved peg) (P = 0.10). The extrusion rate was 32% (12 of 38) for nonsleeved pegs and 0% (0 of 9) for sleeved pegs. Factors unrelated to peg extrusion were patient sex, prior ocular surgery or radiotherapy, presence of giant papillary conjunctivitis, time interval from enucleation to peg placement, and degree of implant vascularization on magnetic resonance imaging. Of the 12 nonsleeved pegs that extruded, a sleeved peg system was subsequently successfully placed in 5 patients, a nonsleeved peg in 1 patient, and 6 patients remained without a peg system. CONCLUSIONS: Hydroxyapatite motility pegs have relatively few complications except for extrusion. The rate of extrusion can be minimized by employing a sleeved peg rather than a nonsleeved peg system.

Adolescent↗
PubMed2004

Final report of the amended safety assessment of PEG-5, -10, -16, -25, -30, and -40 soy sterol.

PEGs Soy Sterol are polyethylene glycol (PEG) derivatives of soybean oil sterols used in a variety of cosmetic formulations as surfactants and emulsifying agents, skin-conditioning agents, and cleansing and solubilizing agents. When the safety of these ingredients were first reviewed, the available data were insufficient to support safety. New data have since been received and the safety of these ingredients in cosmetics has been substantiated. Current concentration of use ranges from a low of 0.05% in makeup preparations to 2% in moisturizers and several other products. PEGs Soy Sterol are produced by the reaction of the soy sterol hydroxyl with ethylene oxide. In general, ethoxylated fatty acids can contain 1,4-dioxane as a byproduct of ethoxylation. The soy sterols include campesterol, stigmasterol, and beta-sitosterol. The distribution of sterols found in oils derived from common plants is similar, with beta-sitosterol comprising a major component. Impurities include sterol hydrocarbons and cholesterol (4% to 6%) and triterpine alcohols, keto-steroids, and other steroid-like substances (4% to 6%). No pesticide residues were detected. PEGS: Because PEGs are an underlying structure in PEGs Soy Sterols, the previous assessment of PEGs was considered. It is generally recognized that the PEG monomer, ethylene glycol, and certain of its monoalkyl ethers are reproductive and developmental toxins. Given the methods of manufacture of PEGs Soy Sterol, there is no likelihood of ethylene glycol or its alkyl ethers being present. Also, the soybean oil sterol ethers in this ingredient are chemically different from the ethylene glycol alkyl ethers of concern. PEGs are not carcinogenic, although sensitization and nephrotoxicity were observed in burn patients treated with a PEG-based cream. No evidence of systemic toxicity or sensitization was found in studies with intact skin. Plant Phytosterols: Intestinal absorption of ingested plant phytosterols is on the order of 5%, with 95% of the material entering the colon. Absorbed plant phytosterols are transported to the blood. Although there are some data suggesting that sulfates of beta-sitosterol can act as abortifacients in rats and rabbits, other studies of well-characterized plant phytosterols and phytosterol esters demonstrated no effect in an estrogen-binding study, a recombinant yeast assay for estrogen or estrogen-like activity, or a juvenile rat uterotrophic assay for estrogen or estrogen-like activity. In a two-generation reproduction study using rats, plant phytosterol esters in the diet had no effect on any parameter of reproduction or fertility. Subcutaneous injections of beta-sitosterol did reduce sperm concentrations and fertility in rats. Sitosterol inhibited tumor promoting activity of 12-O-tetradecanoylphorbol-13-acetate (TPA) in mice after initiation with 7,12-dimethylbenz[a]anthracene (DMBA), and reduced the tumors produced by N-methylnitrosourea in rats. Phytosterols were not genotoxic in several bacterial, mammalian, and in vitro assay systems. Phytosterols decreased epithelial cell proliferation in the colon of mice and rats, and were cytotoxic for human epidermoid carcinoma of the nasopharynx. PEGs Soy Sterols: The acute oral LD50 in rats of PEG-5-25 Soy Sterol was >10 g/kg. The acute dermal LD50 of a liquid eyeliner containing 2%PEG-5 Soy Sterol was >2 g/kg in rabbits. PEG-5-25 Soy Sterol was not a primary irritant in rabbits when applied undiluted. Undiluted PEG-5 Soy Sterol did not cause sensitization in guinea pigs. PEGs Soy Sterol did not produce ocular toxicity in rabbits. PEG-5 Soy Sterol was negative in the Ames mutagenicity test, with or without metabolic activation. PEG-5 Soy Sterol, at concentrations up to 2%in formulation, did not cause dermal or ocular irritation, dermal sensitization, or photosensitization in clinical studies. Because of the possible presence of 1,4-dioxane reaction product and unreacted ethylene oxide residues, it was considered necessary to use appropriate procedures to remove these from PEGs Soy Sterol before blending them into cosmetic formulations. Based on the systemic toxicity and sensitization seen with PEGs applied to damaged skin, it was recommended that PEGs Soy Sterol should not be used in cosmetic products applied to damaged skin. Although no dermal absorption data were available, oral studies demonstrate that phytosterols and phytosterol esters are not significantly absorbed and do not result in significant systemic exposure. Some small amounts did appear in the ovaries, however. This raises a concern about the potential presence of free phytosterols and beta-Sitosterol, which could have antiestrogenic, antiprogestational, gonadotrophic, antigonadotrophic, and antiandrogenic effects in PEG sterols. These concerns are alleviated by the extensive data showing that well-defined phytosterols and phytosterol esters are not estrogenic and do not pose a hazard to reproduction. Likewise, the absence of impurities in plant phytosterols and phytosterol esters and extensive data demonstrating the absence of any genotoxicity in bacterial and mammalian systems mitigate against the possibility of any carcinogenic effect with those same well-characterized materials. The Cosmetic Ingredient Review (CIR) Expert Panel concluded that the PEGs Soy Sterol are safe as used in cosmetic products.

Animals↗
PubMed1999

Complications associated with pegging hydroxyapatite orbital implants.

OBJECTIVE: Prior studies of hydroxyapatite orbital implant complications have primarily focused on complications of the implant itself with only occasional mention of the complications associated with the peg system. This in part may be because of a low rate of pegging and, thus, a small sample size to evaluate. Therefore, a full range of complications that can occur with pegging has not been presented. The objective of this study was to determine the complications associated with pegging and to discuss ways to manage them. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS/INTERVENTION: The authors analyzed all of the complications associated with pegging 165 of a possible 275 hydroxyapatite implants implanted by 2 surgeons over 7 years. MAIN OUTCOME MEASURES: The following data were recorded: type of surgery performed, size of implant used, type of hydroxyapatite used, peg system used, time of pegging, follow-up duration, problems encountered, and treatment. RESULTS: Sixty-two (37.5%) of the 165 patients who had pegged implants were found to have problems with their pegs. Twenty-one (33.8%) of the 62 patients with peg problems had more than 1 peg-related problem. Complications associated with pegging included discharge (37%; 23 of 62), pyogenic granulomas (30.6%; 19 of 62), peg falling out (29%; 18 of 62), poor transfer of movement (11.2%; 7 of 62), clicking (11.2%; 7 of 62), conjunctiva overgrowing peg (4.8%; 3 of 62), poor-fitting sleeve (4.8%; 3 of 62), part of sleeve shaft visible (4.8%; 3 of 62), peg drilled on an angle (4.8%; 3 of 62), hydroxyapatite visible around peg hole (3.2%; 2 of 62), peg drilled off-center (3.2%; 2 of 62), popping peg (3.2%; 2 of 62), and excess movement of peg (3.2%; 2 of 62). The most serious complication occurring in two individuals (3.2%) was implant infection requiring implant removal. CONCLUSION: There are several potential complications that can occur after pegging the hydroxyapatite implant. These problems are generally of a minor nature but often require additional patient visits that would not ordinarily have been required if the peg was not in place. The most serious peg problem is implant infection, which may necessitate implant removal. These potential peg problems should be reviewed with the patient before the procedure is performed.

Adolescent↗
PubMed2005

Biodistribution properties of nanoparticles based on mixtures of PLGA with PLGA-PEG diblock copolymers.

The basic characteristics and the biodistribution properties of nanoparticles prepared from mixtures of poly(lactide-co-glycolide) (PLGA) with poly(lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) copolymers were investigated. A PLGA(45)-PEG(5) copolymer of relatively low PEG content and a PLGA(5)-PEG(5) copolymer of relatively high PEG content were included in the study. Increasing the PLGA-PEG content of the PLGA/PLGA-PEG mixture, or when PLGA(45)-PEG(5) was replaced by PLGA(5)-PEG(5), a decrease in the size of the nanoparticles and an increase in the rate of PEG loss from the nanoparticles were observed. The blood residence of the PLGA/PLGA(45)-PEG(5) nanoparticles increased as their PLGA-PEG content was increased, reaching maximum blood longevity at 100% PLGA(45)-PEG(5). On the contrary, the blood residence of PLGA/PLGA(5)-PEG(5) nanoparticles exhibited a plateau maximum in the range of 80-100% PLGA(5)-PEG(5). At PLGA-PEG proportions lower than 80%, the PLGA/PLGA(45)-PEG(5) nanoparticles exhibited lower blood residence than the PLGA/PLGA(5)-PEG(5) nanoparticles, whereas at PLGA-PEG proportions higher than 80%, the PLGA/PLGA(45)-PEG(5) nanoparticles exhibited higher blood residence than the PLGA/PLGA(5)-PEG(5) nanoparticles. These findings indicate that apart from the surface PEG content, the biodistribution properties of the PLGA/PLGA-PEG nanoparticles are also influenced by the size of the nanoparticles and the rate of PEG loss from the nanoparticles.

Animals↗
PubMed2006

Chitosan-g-PEG/DNA complexes deliver gene to the rat liver via intrabiliary and intraportal infusions.

BACKGROUND: Chitosan has been shown to be a non-toxic and efficient vector for in vitro gene transfection and in vivo gene delivery through pulmonary and oral administrations. Recently, we have shown that chitosan/DNA nanoparticles could mediate high levels of gene expression following intrabiliary infusion 1. In this study, we have examined the possibility of using polyethylene glycol (PEG)-grafted chitosan/DNA complexes to deliver genes to the liver through bile duct and portal vein infusions. METHODS: PEG (Mw: 5 kDa) was grafted onto chitosan (Mw: 47 kDa, deacetylation degree: 94%) with grafting degrees of 3.6% and 9.6% (molar percentage of chitosan monosaccharide units grafted with PEG). The stability of chitosan-g-PEG/DNA complexes was studied by measuring the change in particle size and by agarose gel electrophoresis against bile or serum challenge. The influence of PEG grafting on gene transfection efficiency was evaluated in HepG2 cells using luciferase reporter gene. Chitosan and chitosan-g-PEG/DNA complexes were delivered to the liver through bile duct and portal vein infusions with a syringe pump. Gene expression in the liver and the distribution of gene expression in other organs were evaluated. The acute liver toxicity of chitosan and chitosan-g-PEG/DNA complexes was examined by measuring serum alanine aminotranferase (ALT) and aspartate aminotransferase (AST) activities as a function of time. RESULTS: Both chitosan and chitosan-g-PEG displayed comparable gene transfection efficiency in HepG2 cells. After challenge with serum and bile, chitosan-g-PEG/DNA complexes, especially those prepared with chitosan-g-PEG (GD = 9.6%), did not form large aggregates like chitosan/DNA complexes but remained stable for up to 30 min. In addition, chitosan-g-PEG prevented the degradation of DNA in the presence of serum and bile. On day 3 after bile duct infusion, chitosan-g-PEG (GD = 9.6%)/DNA complexes mediated three times higher gene expression in the liver than chitosan/DNA complexes and yielded background levels of gene expression in other organs. On day 1 following portal vein infusion, gene expression level induced by chitosan/DNA complexes was hardly detectable but chitosan-g-PEG (GD = 9.6%) mediated significant transgene expression. Interestingly, transgene expression by chitosan-g-PEG/DNA complexes in other organs after portal vein infusion increased with increasing grafting degree of PEG. The ALT and AST assays indicated that grafting of PEG to chitosan reduced the acute liver toxicity towards the complexes. CONCLUSION: This study demonstrated the potential of chitosan-g-PEG as a safe and more stable gene carrier to the liver.

Animals↗
PubMed2004

Protein and bacterial fouling characteristics of peptide and antibody decorated surfaces of PEG-poly(acrylic acid) co-polymers.

The potential for base poly(ethylene glycol) graft poly(acrylic acid) PEG-g-PA copolymers and surface-modified PEG-g-PA materials to inhibit random protein fouling and bacterial adhesion are investigated. PEG-g-PA co-polymers were synthesized that inhibited non-specific protein and cellular adhesion. PEG-g-PA co-polymers were then covalently modified with either cell adhesion peptides (YRGDS, YEILDV) or fragments of antibodies to monocyte/macrophage integrin receptors (Anti-VLA4, Anti-beta1, Anti-beta2, and Anti-CD64) known to enhance macrophage adhesion and, perhaps, modulate their activation. Materials produced in this work were characterized using: hydrophobicity by contact angle; angle-resolved X-ray Photoelectron Spectroscopy to confirm the presence of PEG in the bulk material and the surface; degree of hydration; differential scanning calorimetry; and thermal gravimetric analysis. To evaluate the non-fouling efficacy of the various modified surfaces, three proteins, human serum albumin, human fibronectin (Fraction I) and human immunoglobulin were 125I labeled. Samples of base PEG-g-PA and PEG-g-PA, modified with various peptides, were exposed to solutions containing either 2 or 200 microg/ml of one of the labeled proteins at 37 degrees C for 24 h. PEG-g-PA substrata modified with directly bound peptides exhibited protein adsorption that varied depending upon the surface bounded peptide. PEG-g-PA modified with peptides linked by linear PEG tethers reduced protein adsorption at 24 h by approximately 45% in comparison to PEG-g-PA. Peptides linked by way of StarPEO and StarlikePEO tethers further decreased protein adsorption in comparison to PEG-g-PA. The ability of peptide:PEOtethers to inhibit protein adsorption appeared to be a function of type and surface coverage of the PEO tether and not influenced by the amount or molecular structure the tethered peptide. Peptides directly coupled to the PEG-g-PA increased the amount of protein fouling relative to controls and there appeared to be some dependency of the amount of protein adsorption on which peptide was tethered. Two 14C-labeled pathogens, Staphylococcus epidermidis and Pseudomonas aeruginosa, were used to quantify the degree of bacterial adhesion using two types of laminar flow cell chambers; one that provided invasive sampling of the target substrata and one that provided non-invasive microscopic surveillance of adhering bacterial cells. Attachment of both species to PEG-g-PA and peptide-modified PEG-g-PA was reduced compared to the basic poly(acrylic acid). Presence of peptides on the surface, whether directly bound or bound by the PEO tether did not influence adhesion of P. aeruginosa relative to controls. S. epidermidis adhesion rates increased slightly for those materials where peptides were directly bound to the surface but were reduced relative to base PEG-g-PA when peptides were bound by PEO tethers. All PEG-g-PA surfaces modified with fragments of monoclonal antibodies dramatically enhanced bacterial initial adhesion rates and maximum extent of attachment.

Acrylic Resins↗
PubMed2005

Safety assessment on polyethylene glycols (PEGs) and their derivatives as used in cosmetic products.

This assessment focusses on polyethylene glycols (PEGs) and on anionic or nonionic PEG derivatives, which are currently used in cosmetics in Europe. These compounds are used in a great variety of cosmetic applications because of their solubility and viscosity properties, and because of their low toxicity. The PEGs, their ethers, and their fatty acid esters produce little or no ocular or dermal irritation and have extremely low acute and chronic toxicities. They do not readily penetrate intact skin, and in view of the wide use of preparations containing PEG and PEG derivatives, only few case reports on sensitisation reactions have been published, mainly involving patients with exposure to PEGs in medicines or following exposure to injured or chronically inflamed skin. On healthy skin, the sensitising potential of these compounds appears to be negligible. For some representative substances of this class, information was available on reproductive and developmental toxicity, on genotoxicty and carcinogenic properties. Taking into consideration all available information from related compounds, as well as the mode and mechanism of action, no safety concern with regard to these endpoints could be identified. Based on the available data it is therefore concluded that PEGs of a wide molecular weight range (200 to over 10,000), their ethers (laureths. ceteths, ceteareths, steareths, and oleths), and fatty acid esters (laurates, dilaurates, stearates, distearates) are safe for use in cosmetics. Limited data were available for PEG sorbitan/sorbitol fatty acid esters, PEG sorbitan beeswax and PEG soy sterols. Taking into account all the information available for closely related compounds, it can be assumed that these compounds as presently used in cosmetic preparations will not present a risk for human health. PEG castor oils and PEG hydrogenated castor oils have caused anaphylactic reactions when used in intravenous medicinal products. Their topical use in cosmetics is, however, considered safe as they are not expected to be systemically available. As all PEGs and PEG derivatives, they must not be applied to damaged skin. Manufacturers of PEGs and PEG derivatives must continue their efforts to remove impurities and by-products such as ethylene oxide and 1,4-dioxane. Overall, it is concluded, that the PEGs covered in this review are safe for use in cosmetics under the present conditions of intended use.

Animals↗
PubMed2002

Complications of motility peg placement for porous hydroxyapatite orbital implants.

AIM: To evaluate the complications associated with pegging of porous hydroxyapatite orbital implants. METHODS: Complications associated with pegging were retrospectively reviewed from the charts of 100 of 133 patients with hydroxyapatite implantation from 1993 to 2000. RESULTS: 48 (48%) of the 100 hydroxyapatite implanted patients who had undergone pegging were found to have problems with their pegs, including discharge (45.8%), peg falling out (20.8%), pyogenic granulomas (16.7%), popping peg (14.6%), hydroxyapatite visible around peg hole (8.3%), part of peg shaft visible (6.2%), peg drilled off centre (6.2%), peg drilled at an angle (4.2%), and excess movement of peg (4.2%). The standard peg fell out statistically more often than the peg and sleeve system (Yates's corrected chi(2), p=0.038). There was a trend towards complications of the peg with use of a standard peg (versus sleeved peg) (p=0.226). CONCLUSIONS: There are several potential complications of pegging. Most complications are minor and can be managed successfully.

Adolescent↗