Safety and toxicological evaluation of undenatured type II collagen

Previous research has shown that undenatured type II collagen is effective in the treatment of arthritis. The present study evaluated the broad-spectrum safety of UC-II by a variety of toxicological assays including acute oral, acute dermal, primary dermal irritation, and primary eye irritation toxicity. In addition, genotoxicity studies such as Ames bacterial reverse mutation assay and mouse lymphoma tests, as well as a dose-dependent 90-day sub-chronic toxicity study were conducted. Safety studies indicated that acute oral LD₅₀ of UC-II was greater than 5000?mg/kg in female Sprague-Dawley rats. No changes in body weight or adverse effects were observed following necropsy. Acute dermal LD₅₀ of UC-II was determined to be greater than 2000?mg/kg. Primary skin irritation tests conducted on New Zealand Albino rabbits classified UC-II as slightly irritating. Primary eye irritation tests conducted on rabbits indicated that UC-II was moderately irritating to the eye. UC-II did not induce mutagenicity in the bacterial reverse mutation test in five Salmonella typhimurium strains either with or without metabolic activation. Similarly, UC-II did not induce a mutagenic effect in the gene mutation test in mouse lymphoma cells either with or without metabolic activation. A dose-dependent 90-day sub-chronic toxicity study revealed no pathologically significant changes in selected organ weights individually or as percentages of body or brain weights. No significant changes were observed in hematology and clinical chemistry. Therefore, the results from the current study show a broad-spectrum safety profile of UC-II.     

Safety and toxicological evaluation of Aflapin®: A novel Boswellia-derived anti-inflammatory product

Boswellia serrata gum resin has been used for treatment of various ailments in different cultures for thousands of years. Aflapin^® is a novel synergistic composition derived from B. serrata gum resin (Indian Patent Application No. 2229/CHE/2008). Aflapin is significantly better as an anti-inflammatory agent compared to the Boswellia extracts presently available in the market. To assess the safety of Aflapin, a battery of acute and sub-acute toxicity studies were conducted in various animal models according to the OECD test guidelines. The acute oral LD50 of Aflapin was greater than 5000?mg/kg in female Sprague Dawley (SD) rats. Acute dermal LD50 of Aflapin was greater than 2000?mg/kg in SD rats. A primary dermal irritation study conducted using New Zealand White rabbits indicated that Aflapin is non-irritating to skin. Aflapin caused minimal ocular irritation in a primary eye irritation test conducted on New Zealand Albino rabbits. A repeat dose 28-day sub-acute oral toxicity study in SD rats demonstrated no significant signs of toxicity. Various evaluations including hematology, clinical chemistry, gross necropsy, and histopathology did not show any significant adverse changes. The NOAEL of Aflapin was found to be greater than 2500?mg/kg body weight. These studies demonstrate broad spectrum safety of Aflapin in animal models.     

Safety and toxicological evaluation of a novel chromium(III) dinicocysteinate complex

Chromium(III) is an essential trace element required for normal protein, fat and carbohydrate metabolism. It also helps in energy production and increasing lean body mass. Chromium(III) dinicocysteinate (CDNC) is a unique form of bioavailable chromium(III). This study was focused on determining the broad spectrum safety of CDNC. Acute oral, acute dermal, primary dermal and eye irritation studies, Ames’ bacterial reverse mutation assay, mammalian erythrocyte micronucleus test, and a 90-day dose-dependent oral toxicity study were conducted. Acute oral and dermal LD₅₀ of CDNC was found to be greater than 2000?mg/kg in Sprague-Dawley rats. A primary skin irritation study in New Zealand Albino rabbits demonstrated CDNC as slightly irritating. An eye irritation study exhibited that CDNC is moderately irritating. Ames’ bacterial reverse mutation assay and mammalian erythrocyte micronucleus test demonstrated CDNC as non-mutagenic. A dose-dependent 90-day oral toxicity study demonstrated no significant toxicity of CDNC. Body weight, food and water consumption, selected organ weights (expressed as percentages of body or brain weights), ocular health, hematology, blood chemistry, and histopathology showed no abnormal changes. Clinical and histopathological evaluation of CDNC identified a dose level of 5.7?mg/kg/day as the no observed adverse effect level (NOAEL). Overall, these results demonstrate the broad spectrum safety of CDNC.     

Acute toxicity studies with insect attractants.

Eight insect attractants and one inhibitor of a sex attractant were tested for acute oral and aerosol inhalation toxicity in rats, for acute dermal toxicity, eye irritation, and primary skin irritation on rabbits, and for toxicity to rainbow trout and bluegill sunfish. Except for phenethyl propionate + eugenol, 7:3 (acute dermal LD50, 1220 mg/kg), none of the test materials was classified as more than slightly toxic. (Z)-7-Dodecen-1-ol acted as a primary skin irritant, since it caused superficial chemical burns.     

Genotoxicity,acute oral and dermal toxicity,eye and dermal irritation and corrosion and skin sensitisation evaluation of silver nanoparticles

Abstract

To clarify the health risks related to silver nanoparticles (Ag-NPs), we evaluated the genotoxicity, acute oral and dermal toxicity, eye irritation, dermal irritation and corrosion and skin sensitisation of commercially manufactured Ag-NPs according to the OECD test guidelines and GLP. The Ag-NPs were not found to induce genotoxicity in a bacterial reverse mutation test and chromosomal aberration test, although some cytotoxicity was observed. In acute oral and dermal toxicity tests using rats, none of the rats showed any abnormal signs or mortality at a dose level of ～ 2000 mg/kg. Similarly, acute eye and dermal irritation and corrosion tests using rabbits revealed no significant clinical signs or mortality and no acute irritation or corrosion reaction for the eyes and skin. In a skin sensitisation test using guinea pigs, one animal (1/20) showed discrete or patchy erythema, thus Ag-NPs can be classified as a weak skin sensitiser.     

Acute, Distribution, and Subchronic Toxicological Studies of Succinate Tartrates

The estimated single-dose oral toxicity (50% lethality) of succinatetartrates (ST) was 2–3 g/kg in rats. ST produced minimalto moderate dermal irritation but no evidence of systemic toxicityin a standard acute percutaneous toxicity test in rabbits. STwas not an eye irritant in a standard rabbit low-volume eyeirritation test ST was not genotoxic in a series of six genotoxicitytests. A 14-day oral gavage study in rats at a dose range of0.05–1.0 g ST/kg/day produced only gastric irritation.The no-observed-effect level (NOEL) for gastric irritation was0.1 g/kg for males and 0.05 g/kg for females. A 28-day percutaneoustoxicity study in rabbits produced minimal to moderate dermalirritation and no adverse systemic effects at a high dose of450 mg ST/kg/day. Single-dose absorption, distribution, andelimination (ADE) studies in male rats showed that 10–15%of an oral dose and 1–3% of a dermal dose were absorbed.Approximately 98% of the orally administered ST was eliminatedas ¹⁴C in urine, feces, or expired CO₂ after 72 hr. Approximately80% of the dermally absorbed ¹⁴C dose was eliminated in urine,feces, or expired CO₂ after 72 hr. In conclusion, no adverseeffects were noted in acute toxicity, genotoxicity, or subchronictoxicity studies conducted with ST.     

Dermal toxicity,eye and dermal irritation and skin sensitization evaluation of a new formulation of Bacillus thuringiensis var israelensis SH-14

Bacillus thuringiensis (Bt) is the best known and most widely used of all pesticidal microbes. The aim of this study was to assess the toxicity of a new formulation of Bacillus thuringiensis var israelensis SH-14 in rats through acute dermal toxicity, dermal and eye irritation experiments. The acute dermal toxicity and dermal and eye irritation studies were performed using rabbits according to the United States Environmental Protection Agency guidelines 885.3100, 870.2500 and 870.2500, respectively. The skin sensitization study was carried out in accordance to the EPA OPPTS 870.2600 using guinea pigs. There was no mortality and no evidence of treatment-related toxicity in acute dermal toxicity test. No dermal responses, including erythema/eschar or edema, were found in rabbits treated with the new formulation of Bti SH-14. Minimum response was observed after eye application of test substance. No skin sensitization reactions were observed after the challenge with the new formulation of Bti SH-14 in the Bti SH-14-treated guinea pigs. In summary, the present study demonstrated that the new formulation of Bti SH-14 is not acutely toxic via dermal route, has low eye irritation and would not cause dermal irritation or hypersensitivity to tested animals.     

Acute toxicity, subchronic dermal toxicity, and delayed contact sensitization evaluations of dicyclopentenyloxyethyl methacrylate in rabbits and guinea pigs

The subchronic dermal toxicity of dicyclopentenyloxethyl methacrylate (DPOMA) was evaluated in young adult New Zealand White rabbits, and its potential to produce delayed contact sensitization was evaluated in Harley guinea pigs by a modified Buehler's closed patch technique. In addition, studies were conducted to evaluate the acute systemic toxicity of DPOMA in rats (oral) and rabbits (dermal), and its eye and skin irritancy in rabbits. In the subchronic dermal toxicity study, 4 groups of rabbits were treated percutaneously with DPOMA at 0 (acetone), 10, 107, and 1067 (undiluted) mg/kg X day in a volume of 1 ml/kg, over a 4-wk period. The application sites were unoccluded. No deaths occurred, and no signs of systemic toxicity were observed. No treatment-related effects were seen on body weights, hematology, clinical chemistry, urinalysis, organ weights, or histopathology (except the treated skin). The only treatment-related effect was slight to moderate skin irritation in the mid- and high-dose groups. The severity of skin irritaton was dependent on the number of applications and the concentration of DPOMA. Maximal skin irritation occurred after 1 wk. No skin irritation was seen in the control and low-dose group. In the DCS study, guinea pigs received 6 induction doses of 0.5 ml 100% DPOMA and were challenged with 0.5 ml of 50% (w/v) DPOMA in acetone 2 wk after the last induction treatment. No erythema or edema was observed in any of the challenged guinea pigs in either the treated and control groups. These acute toxicity studies indicate that DPOMA is practically nontoxic by a single exposure via both oral and dermal routes (the oral LD50 in rat and dermal LD50 in rabbits were greater than 5.0 g/kg body weight), slightly irritating to the skin, and inconsequentially irritating to the eyes. The no-observed-effect level (NOEL) for systemic toxicity of DPOMA applied repeatedly to rabbits skin is at least 1067 mg/kg X d. DPOMA is not a strong or moderate skin sensitizer in guinea pigs.     

肤福牌皮肤消毒护肤喷雾剂的急性、亚急性毒性实验和刺激实验

目的：评价肤福牌皮肤消毒护肤喷雾剂的毒性和刺激性。方法：按照消毒技术规范（2002年版）进行急性和亚急性毒性实验、完整和破损皮肤刺激实验、急性眼刺激实验以及微核实验。结果：急性灌胃毒性实验结果显示,该产品对雌、雄小鼠的LD50〉5000mg／kg;对家兔多次完整皮肤、一次破损皮肤刺激实验,以及急性眼刺激实验均属无刺激性;500～5000mg／kg微核实验结果呈阴性;亚急性经口毒性实验,对雌、雄SD大鼠未观察到有害作用的剂量为1000mg／kg。结论：该产品属实际无毒级,无刺激性,安全性良好。     

拟原白头翁素A毒性试验研究

目的为了对拟原白头翁素Ａ进行初步毒理学安全性评价。方法采用大鼠急性经口和经皮毒性试验，大鼠皮肤和大白兔眼粘膜刺激试验，Ａｍｅｓ试验，小鼠骨髓微核试验，小鼠睾丸初级精母细胞染色体畸变试验。结果大鼠急性经口ＬＤ５０４．６７３９（ＩＣ４．０６１４～５．３７８７）ｇ·ｋｇ－１，经皮ＬＤ５０＞２．０ｇ·ｋｇ－１，根据化合物毒性分级为低毒；对大鼠皮肤无刺激作用，对大白兔眼粘膜有中等刺激；Ａｍｅｓ试验、小鼠骨髓微核试验和小鼠睾丸初级精母细胞染色体畸变试验阴性。结论拟原白头翁素Ａ为低毒、致突变试验阴性的化合物。     

Safety and toxicological evaluation of a novel,water-soluble undenatured type II collagen

Abstract

This study was conducted to determine the broad-spectrum safety of a novel, water-soluble undenatured type II collagen (NEXT-II) derived from chicken sternum cartilage. The presence of epitope in NEXT-II was confirmed by using a commercial kit. The acute oral LD₅₀ of NEXT-II was found to be greater than 5000?mg/kg bw in rats, while the single-dose acute dermal LD₅₀ was greater than 2000?mg/kg bw. The primary dermal irritation index (PDII) of NEXT-II was found to be 1.8 and classified as slightly irritating to the skin. In primary eye irritation studies, the maximum mean total score (MMTS) of NEXT-II was observed to be 7.3 and classified as minimally irritating to the eye. Long-term safety studies were conducted in dogs over a period of 150?d, and no significant changes were observed in body weight, heart rate, respiration rate and blood chemistry. NEXT-II does not induce mutagenicity in the bacterial reverse mutation test in five Salmonella typhimurium strains either with or without metabolic activation. Furthermore, two experiments were conducted to assess the potential of NEXT-II to induce mutations with and without metabolic activation at the mouse lymphoma thymidine kinase locus using the cell line L5178Y. No biologically relevant increase of mutants was observed. Also, no dose-dependent toxicity was observed. Furthermore, colony sizing showed no clastogenic effects induced by NEXT-II under the experimental conditions. These studies demonstrated the broad spectrum of safety of NEXT-II.     

Evaluation of the toxicity of graphene oxide exposure to the eye

Graphene and its derivatives are the new carbon nanomaterials with the prospect for great applications in electronics, energy storage, biosensors and medicine. However, little is known about the toxicity of graphene or its derivatives in the case of occasional or repeated ocular exposure. We performed in vitro and in vivo studies to evaluate the toxicity of graphene oxide (GO) exposure to the eye. Primary human corneal epithelium cells (hCorECs) and human conjunctiva epithelium cells (hConECs) were exposed to GO (12.5–100?μg/mL). Acute GO exposure (2?h) did not induce cytotoxicity to hCorECs. However, short-term GO exposure (24?h) exerted significant cytotoxicity to hCorECs and hConECs with increased intracellular reactive oxygen species (ROS). Glutathione (GSH) reduced the GO-induced cytotoxicity. We further performed acute eye irritation tests in albino rabbits according to the Organization for Economic Cooperation and Development (OECD) guidelines, and the rabbits did not exhibit corneal opacity, conjunctival redness, abnormality of the iris, or chemosis at any time point after the instillation of 100?μg/mL of GO. However, 5-day repeated GO exposure (50 and 100?μg/mL) caused reversible mild corneal opacity, conjunctival redness and corneal epithelium damage to Sprague-Dawley rats, which was also alleviated by GSH. Therefore, our study suggests that GO-induced time- and dose-dependent cytotoxicity to hCorECs and hConECs via oxidative stress. Occasional GO exposure did not cause acute eye irritation; short-term repeated GO exposure generally resulted in reversible damage to the eye via oxidative stress, which may be alleviated by the antioxidant GSH.     

Safety and toxicological evaluation of AlgaeCal® (AC), a novel plant-based calcium supplement

The present study was conducted to examine the safety of a novel plant-based calcium supplement, derived from marine algae and containing high levels of calcium, magnesium, and other bone supporting minerals (commercially known as AlgaeCal^® (AC)). The present study evaluated the broad-spectrum safety of AC using a variety of toxicological assays including acute oral, acute dermal, primary skin irritation, and primary eye irritation toxicity. Under the conditions of the study, the acute oral LD₅₀ of AC was found to be greater than 5000?mg/kg body weight in rats, while the single acute dermal LD₅₀ was greater than 2000?mg/kg body weight. The primary skin irritation index of AC was found to be 0.4 and classified as slightly irritating to the skin. In primary eye irritation studies, the maximum mean total score of AC was observed to be 13.7 and classified as mildly irritating to the eye. Furthermore, another independent set of studies was conducted to obtain preliminary data for the teratogenic effects of AC in pregnant rats likely to arise from repeated gestational exposure, via oral gavage, over a test period of implantation through gestation (gestation days 5–19). Under the conditions of this pilot study, the effect of daily administration of AC by oral gavage at dose levels of 0, 500, 2500, and 5000?mg/kg/day during gestation days 5–19 of a 21-day pregnancy has appeared to result in no adverse toxicological effects to the pregnant rat or its developing offspring. A slight, non-significant increase in the incidence of incomplete sterna ossification (5^th center) was observed. Under the conditions of the study, a no-observed-adverse effect level (NOAEL) of 5000?mg/kg/day of AC during pregnancy of the rat was observed. Overall, no significant toxicities of AC were observed in these toxicity models. Therefore, the results from the current study demonstrate a broad-spectrum safety profile of AC.     

Acute dermal toxicity of two quarternary organophosphonium salts in the rabbit

Tetrabutyl phosphonium chloride and tetrabutyl phosphonium bromide were evaluated for their potential to cause primary dermal irritation and acute dermal toxicity in rabbits. Both chemicals were found to not only be severely irritating to skin, but the pure hygroscopic chemicals caused death in more than half the number of rabbits used in the primary dermal irritation tests. Further investigations revealed the single-application dermal LD50 of tetrabutyl phosphonium chloride (Bu4PCl) (using an ethylene carbonate (EC) vehicle) was 600 mg/kg for male rabbits and 500 mg/kg for female rabbits. The single-application dermal LD50 of tetrabutyl phosphonium bromide (Bu4PBr) (using the EC vehicle) was 700 mg/kg for male rabbits and 850 mg/kg for female rabbits. The dermal LD50 of pure undiluted Bu4PCl was 225 mg/kg for male rabbits. These data indicate that Bu4PCl and Bu4PBr represent a substantial acute dermal toxicity hazard.     

Toxicological studies on sophorolipid derivatives. (I). Acute toxicity, eye irritation, primary skin irritation, skin sensitization, phototoxicity, photosensitization, mutagenicity of polyoxypropylene (12) [(2'-0-beta-D-glucopyranosyl-beta-D-glucopyranosyl)oxy-] fatty acid ester-

Acute toxicity, eye irritation, primary skin irritation, skin sensitization, phototoxicity, photosensitization and mutagenicity of sophorolipid derivatives were studied in rats, mice, rabbits, guinea pigs and Salmonella typhimurium strains. The acute oral toxicity of sophorolipid (SL) which Torulopsis bombicola produces, and its derivatives (PSL, Ethyl-SL and Oleyl-SL) were shown to be very low. The LD50 values of PSL ranged from 10 g/kg to 16 g/kg on oral administration in rats and mice, and from 5.8 g/kg to 6.6 g/kg on subcutaneous administration in mice. The oral LD50 values of Ethyl-SL and Oleyl-SL were estimated to be greater than 15 g/kg and that of SL was 12.5 g/kg. In eye irritation study, PSL failed to produce any reactions at 50% concentration even when the rabbit eye was not subsequently washed. SL, Ethyl-SL, Oleyl-SL and Tween 20 were "no irritant" or "slight irritant" to the rabbit eye at 20% concentration. PSL showed no irritancy to both the intact and abraded guinea pig skin at 50% concentration. And in other examinations, it was also indicated that PSL had no potentials of skin sensitization, phototoxicity and photosensitization in guinea pigs and had no potentials of mutagenicity in Salmonella typhimurium TA98 and TA100.     

Safety profile of silver sulfadiazine-bFGF-loaded hydrogel for partial thickness burn wounds

In the present investigation, the safety of novel combinational silver sulfadiazine-bFGF-loaded hydrogel was assured by performing acute skin irritation, sensitization, acute dermal toxicity, and eye irritation in compliance with the Organization for Economic Co-operation and Development guidelines. In the skin irritation study, placebo, test, and positive control (0.8% w/v aqueous solution of formaldehyde) were applied on New Zealand rabbits and monitored for abnormal skin responses including erythema and edema. The placebo and test formulation did not induce any adverse reactions and were classified as nonirritating materials. In the skin sensitization test, guinea pigs were sensitized by positive control (0.1% w/v 1-chloro-2,4-dinitrobenzene in 10% of propylene glycol as a standard skin sensitizing agent), placebo, and test formulations. Weak sensitization was observed in the placebo and test formulation treated groups. Additionally, acute dermal toxicity test was performed in Wistar rats, where no signs of toxicity were observed in biochemical, hematological, and histopathological studies. Moreover, the acute eye irritation test was carried out in rabbits and no abnormal clinical signs were evident in the cornea or iris. As a whole, these findings suggest that the hydrogel formulation does not cause any skin irritation, skin sensitizationand dermal toxic effects, and eye irritation following dermal and ocular applications, respectively. Therefore, all the findings obtained from this preclinical study indicated that this hydrogel formulation is nontoxic and safe for use in animal models.     

Maleic acid dimethylester: evaluation of dermal toxicity and genotoxicity

Maleic acid dimethylester (MAD) was investigated in acute and subacute dermal toxicity studies, for sensitization potential, and for in vivo and in vitro genotoxicity. The acute dermal toxicity in rats was low (LD50 greater than 2000 mg/kg body weight). Only local effects, erythema and necrosis, occurred at the site of application. Corresponding dose-related effects were observed in a 28-day repeated dermal toxicity study in rats. Treatment-related systemic alterations were observed in feed consumption, body weights, haematology and clinical chemistry at 170 and 500 mg MAD/kg body weight. Based on the results of this study, the no-toxic-effect level of MAD was considered to be 60 mg/kg body weight/day. However, slight dermal irritative effects were also present at the lowest dose level (60 mg/kg body weight). The primary skin irritation test in rabbits showed only slight erythema and oedema. The results of the maximization test in guinea-pigs indicated a clear sensitizing potential of MAD. In the Ames test, with five strains of Salmonella typhimurium, MAD was not mutagenic up to the highest dose level of 5000 micrograms/plate. In the micronucleus test, in which mice were given 1000 mg MAD/kg body weight by gavage the compound revealed no clastogenic effects.     

Toxicological assessment of heat transfer fluids proposed for use in solar energy applications,II

Ten commercially available solar heat transfer fluids as well as three samples of used fluids (an ethylene glycol, a propylene glycol, and a silicone fluid) obtained from operating solar hot water systems were evaluated for acute oral toxicity in female rats and for dermal and ocular irritation in female rabbits. Mutagenicity testing was conducted in the Salmonella mutagenicity assay (TA 1538, TA 98, TA 1535, TA 100). Oral LD₅₀ values ranged from 7.0 g/kg for ethylene glycol-based products to >24 g/kg for propylene glycol, hydrocarbon oils, and silicone fluids. None of the solar fluids was mutagenic at the concentrations tested nor caused more than a slight ocular or dermal irritation. No appreciable differences were observed in evaluations between used and unused fluid samples. The results indicate that the fluids may be considered relatively safe for residential solar energy applications, although based on toxicity testing propylene glycol should be preferred over ethylene glycol. Trifluoroethanol (Fluorinol 100) was included in these studies because of its probable use as a working fluid in organic Rankine cycle waste heat recovery systems. Trifluoroethanol had an LD₅₀ of 0.21 g/kg, was not irritating to rabbit skin nor mutagenic in Salmonella, but demonstrated severe ocular toxicity.     

Amended final report of the safety assessment of t-Butyl Alcohol as used in cosmetics

t-Butyl Alcohol (t-BuOH) is a tertiary aliphatic alcohol that is used as a solvent or an alcohol denaturant and as a perfume carrier in cosmetics. t-BuOH was reported as an ingredient in 32 formulations of eye makeup, fragrance, and shaving preparations, at concentrations ranging from 0.00001% and 0.3%. There is little acute oral toxicity in animals; e.g., the acute oral LD(50) in rats was 3.0 to 3.7 g/kg. In short-term oral studies in rats, t-BuOH at 2% (w/v) or less in drinking water did not cause gross organ or tissue damage in mice, although weight loss was reported and microscopic damage to livers and kidney and alterations such as centrilobular necrosis, vacuolation in hepatocytes, and loss of hepatic architecture were noted. Subchronic oral dosing with t-BuOH increased the mineralization of the kidney, nephropathy, and urinary bladder transitional cell epithelial hyperplasia in rats; and liver damage, chronic inflammation, hyperplasia of transitional cell epithelium urinary, and proliferative changes including hyperplasia and neoplasia in the thyroid in mice. Male rats exposed to t-BuOH were susceptible to alpha 2mu-globulin nephropathy. t-BuOH (99.9%) was a moderate to severe ocular irritant to rabbits and caused mild to moderate dermal irritation to rabbits. It was not considered to be a primary dermal irritant to rabbits. In animal studies, fetotoxicity generally increased with concentration, and fetal weights were slightly depressed at concentrations of 0.5% to 1% t-BuOH. t-BuOH produced a significant increase in the number of resorptions per litter. There was also a significant decrease in the number of live fetuses per litter. t-BuOH reduced maternal weight gain, litter sizes, birth weights, and weights at weaning, and increased perinatal and postnatal mortality. t-BuOH was not mutagenic in several bacterial and mammalian test systems. The principal effects from 2 years of exposure to t-BuOH in drinking water (up to 10 mg/ml for rats and 20 mg/ml for mice) were proliferative lesions (hyperplasia, adenoma, and carcinoma) in the kidneys of exposed male rats, and nephropathy in all exposed groups of female rats. There was some evidence of carcinogenic activity, but it was not consistent between species, sexes, or doses. A repeat-insult patch test (RIPT) test showed no potential for eliciting either dermal irritation or sensitization by 100% t-BuOH. Dermatitis can result from dermal exposure of humans to t-BuOH. In consideration of these data, it was concluded that t-BuOH was (at most) a weak carcinogen and unlikely to have significant carcinogenic potential as currently used in cosmetic formulations. In addition, the renal tubule effects found in male rats were likely an effect of alpha 2mu-globulin. In consideration of the reproductive and developmental toxicity data, the increased incidence of still births occurred at high exposure levels and was likely secondary to maternal toxicity. Based on the available animal and clinical data in this report, it was concluded that t-BuOH is safe as used in cosmetic products.     

Safety studies of pseudo-ceramide SLE66: Acute and short-term toxicity

Topical application of ceramides is reported to improve the structure and texture of the skin. Synthetic pseudo-cermaide, SLE66 has been shown to reduce dryness/scaling/itching of human skin. Although efficacy of topically applied ceramides and their analogs has been investigated to some extent, safety information is scarce. The objective of the present investigation was to evaluate potential adverse effects of SLE66. The oral LD₅₀ of SLE66 in rats and mice was >5000 mg/kg, while dermal LD₅₀ in rats was >2000 mg/kg. In animal and human studies, SLE66 did not cause skin irritation or sensitization. SLE66 does not possess phototoxicity or photosensitization potentials. Instillation of SLE66 into rabbit eye elicited transient conjunctival irritation. In 28 day repeat-dose studies, administration of SLE66 via gavage (daily) or by dermal application (five days/week) to Sprague Dawley rats at levels up to 1000 mg/kg/day did not cause mortality or morbidity. Compared to the controls, the clinical condition of the animals, body weights, feed consumption, hematology, clinical chemistry, organ weights, and gross necropsy findings were unaffected by oral or dermal administration of SLE66. The no-observed-adverse-effect level (NOAEL) for systemic toxicity following oral or dermal administration of SLE66 was 1000 mg/kg/day (the highest level tested).