Exposure to a Nonionic Surfactant Induces a Response Akin to Heat-Shock Apoptosis in Intestinal Epithelial Cells: Implications for Excipients Safety.

Amphipathic, nonionic, surfactants are widely used in pharmaceutical, food, and agricultural industry to enhance product features; as pharmaceutical excipients, they are also aimed at increasing cell membrane permeability and consequently improving oral drugs absorption. Here, we report on the concentration- and time-dependent succession of events occurring throughout and subsequent exposure of Caco-2 epithelium to a "typical" nonionic surfactant (Kolliphor HS15) to provide a molecular explanation for nonionic surfactant cytotoxicity. The study shows that the conditions of surfactant exposure, which increase plasma membrane fluidity and permeability, produced rapid (within 5 min) redox and mitochondrial effects. Apoptosis was triggered early during exposure (within 10 min) and relied upon an initial mitochondrial membrane hyperpolarization (5-10 min) as a crucial step, leading to its subsequent depolarization and caspase-3/7 activation (60 min). The apoptotic pathway appears to be triggered prior to substantial surfactant-induced membrane damage (observed ≥60 min). We hence propose that the cellular response to the model nonionic surfactant is triggered via surfactant-induced increase in plasma membrane fluidity, a phenomenon akin to the stress response to membrane fluidization induced by heat shock, and consequent apoptosis. Therefore, the fluidization effect that confers surfactants the ability to enhance drug permeability may also be intrinsically linked to the propagation of their cytotoxicity. The reported observations have important implications for the safety of a multitude of nonionic surfactants used in drug delivery formulations and to other permeability enhancing compounds with similar plasma membrane fluidizing mechanisms.

Oral administration of lipid oil-in-water emulsions performed with synthetic or protein-type emulsifiers differentially affects post-prandial triacylglycerolemia in rats.

In this study, we compared the impact of administration of size-calibrated lipid emulsions prepared with either synthetic or natural emulsifiers on the post-absorptive plasma triacylglycerol responses in rats. We did this using four types of size-calibrated (10 µm diameter) and metastable (3 days) emulsions with 20% of an oleic acid-rich sunflower oil and 1% of either synthetic emulsifiers (Tween 80 or sodium 2-stearoyl-lactylate) or two proteins (ß-lactoglobulin or sodium caseinate). An oral fat tolerance test was performed in fasted rats by oral administration of each of these formulations in continuous or emulsified forms. Kinetic parameters (AUC0-inf., AUC0-6h, Cmax, Tmax, and T1/2) for the description of the plasma triacylglycerol responses were calculated. AUC0-6h and AUC0-inf. calculated for the protein groups were significantly lower than those of the control and the synthetic groups. These lower values were associated with significant decreases in the Cmax, exacerbated by the emulsion form and with marked decreases in the Tmax as compared to the control group. T1/2 values were differentially affected by the lipid administration forms and by the nature of the emulsifiers. As compared with the control group, T1/2 was largely increased in the sodium stearoyl-2-lactylate group, but on the contrary, largely lowered in the casein group. We concluded that the use of proteins as natural emulsifiers in lipid emulsions decreased the magnitude of post-prandial triacylglycerolemia for the same amount of ingested lipids, when the emulsion size is controlled for. Proteins could be a promising alternative to the widespread use of synthetic emulsifiers in the food industry.

Phytoformulation of Sassurea lappa plant extract: A Single blind, noninvasive and split face study of cream on various skin parameters.

Saussurea lappa (SL) has been reported for its antioxidant and anti-ageing properties. Due to this reason it can be incorporated in a stable phytoformulations for cosmetic use. The objective of the study was to evaluate the anti-aging potential of cosmetic o/w emulsion containing the botanical extract of SL. An emulsion (o/w) was prepared using TEGO® Care 450 (Polyglceryl-3-Methyl Glucose Distearate) emulsifier and final emulsion was loaded with 4 % extract of SL in aqueous phase. This emulsion evaluated for its antioxidant and anti-ageing properties on healthy human subjects using a non-invasive technique called surface evaluation of living skin (SELS). The formulation containing SL extract showed significant (p<0.05) changes in Skin roughness (SEr) as -3.13%, -6.26%, -9.39%; Skin Scaliness (SEsc) as - 4.19%, -8.39%, -12.58%; Skin wrinkles (SEw) as -0.5%, -1.08%, -1.63%; and Skin smoothness (SEsm) as 3.28%, 6.57%, 9.85%, respectively, after 30, 60 and 90 days of continous use. Topical application of the cosmetic cream containing SL extract exerts have a significant anti-aging effects, perhaps due to the presence of Kaempferol, gallic acid, Caffeic acid and other essential phenolics.

A proprietary topical preparation containing EGCG-stearate and glycerin with inhibitory effects on herpes simplex virus: case study.

The effects of a proprietary topical formulation containing EGCG-stearate in 100% glycerin USP were studied in two volunteer patients with recurrent herpes simplex (HSV) type 1. Application during early onset (prodromal stage) in a patient with herpes labialis prevented lesion progression. In a second patient with herpetic stomatitis, application of the formula during a later stage (inflammation stage) led to a remarkably shortened duration of symptoms. In contrast, a third patient provided 100% glycerin USP only as placebo failed to demonstrate any therapeutic or preventive effect against lesion occurrence or duration of lesion and healing time. These results suggest that this proprietary topical preparation could be used effectively to prevent and treat HSV-induced symptoms, and warrants further clinical investigation.

Final amended report on the safety assessment of Octyldodecyl Stearoyl Stearate.

Octyldodecyl Stearoyl Stearate is an ester that functions as a skin-conditioning agent and viscosity-increasing agent. It is reported to be used in 105 cosmetic products at concentrations from 2% to 15%. In an isolated human skin permeation and penetration study, 0.005% of the applied dose permeated the skin, around 3% was found in the epidermis, around 1.5% was in tape stripped skin layers, and around 95% stayed in the material applied to the skin. A formulation having 20.6% Octyldodecyl Stearoyl Stearate was classified as minimally to mildly irritating in an in vitro ocular irritation assay. Several tests of products containing from 7.5% to 12.7% Octyldodecyl Stearoyl Stearate using rabbits produced minimal to mild ocular irritation. One test of 100% Octyldodecyl Stearoyl Stearate (a trade compound) and another of 10% Octyldodecyl Stearoyl Stearate in corn oil using rabbits produced no ocular irritation. Tests using rabbits demonstrated that Octyldodecyl Stearoyl Stearate at use concentrations was non- to mildly irritating to skin; only one study reported moderate irritation. Octyldodecyl Stearoyl Stearate was not mutagenic, with or without S-9 activation, in an Ames test and did not produce a significant increase in micronucleated cells in a mouse in vivo study. In clinical single-insult patch tests at use concentrations, Octyldodecyl Stearoyl Stearate was nonirritating to mildly irritating; in a cumulative irritation study, it caused mild irritation. Octyldodecyl Stearoyl Stearate was nonsensitizing in clinical tests. Because few toxicity data were available on Octyldodecyl Stearoyl Stearate, summaries of data from existing safety assessments of related ingredients (Octyl Dodecanol, Stearic Acid, and Octyl Stearate) were included. Undiluted Octyl Dodecanol was nontoxic during acute oral and dermal studies using rats and guinea pigs. Stearic Acid was nontoxic to rats during acute oral studies, but caused toxicity during subchronic studies. Rabbits treated topically with the acid were not affected adversely, and mild erythema and slight induration were observed when Stearic Acid was administered intradermally to guinea pigs and rabbits. Octyl Stearate had very low acute oral toxicity in rats and mice. Octyl Dodecanol produced only transient mild ocular irritation in rabbits when administered at concentrations up to 100%. Octyl Dodecanol (30% and 100%) was nonirritating to skin in one study using rabbits. In another study using multiple species, 100% Octyl Dodecanol (described as technical grade) caused severe skin irritation in rabbits, moderate irritation in guinea pigs and rats, and no irritation in swine. Stearic Acid was non- to moderately irritating in animal studies, and did not cause photosensitization. In studies using rabbits, undiluted Octyl Stearate caused slight, transient ocular irritation, and minimal skin irritation. Stearic Acid did not induce mitotic crossovers and aneuploidy in Saccharomyces cerevisiae, and was nonmutagenic in the Ames test. In a feeding study using mice, Stearic Acid was noncarcinogenic at doses up to 50 g/kg/day. Mice given subcutaneous injections of the acid had low incidences of carcinomas, sarcomas, and lymphomas. In clinical studies, concentrations of up to 100% Octyl Dodecanol were non- to mildly irritating, nonsensitizing, nonphototoxic, and nonphotosensitizing. Stearic Acid was nonirritating at concentrations up to 100%, and at concentrations up to 13% it was nonsensitizing and nonphotosensitizing. Octyl Stearate (7.6%) in formulation was nonirritating, nonsensitizing, and nonphotosensitizing. Based on skin permeation and penetration data, the Panel does not expect any significant amount of Octyldodecyl Stearoyl Stearate to be systemically available. There is no evidence of systemic toxicity associated with any of the related chemicals reviewed in previous safety assessments. None of the available toxicology or clinical data suggest a concern about adverse skin reactions to Octyldodecyl Stearoyl Stearate, or to any of the related chemicals. There is no evidence of ocular toxicity, except for a mild, transient ocular irritation associated with Octyldodecyl Stearoyl Stearate and the related chemicals. Overall, Octyldodecyl Stearoyl Stearate was considered safe as used in cosmetics.

Final report on the safety assessment of Octyidodecyl Stearoyl Stearate.

Octyldodecyl Stearoyl Stearate functions as an occlusive skin-conditioning agent and as a nonaqueous viscosity-increasing agent in many cosmetic formulations. Current concentrations of use are between 0.7% and 23%, although historically higher concentrations were used. The chemical is formed by a high-temperature, acid-catalyzed esterification reaction of long-chain alcohols (primarily C-20) and a mixture of primarily C-18 fatty acids. Levels of stearic acid, octyldodecanol, and octylydocecyl hydroxystearate in the final product are 5% or less--no other residual compounds are reported. Only limited safety test data were available on Octyldodecyl Stearoyl Stearate, but previous safety assessments of long-chain alcohols and fatty acids found these precursors to be safe for use in cosmetic formulations. Octyldodecyl Stearoyl Stearate produced no adverse effects in acute exposures in rats. The chemical was mostly nonirritating to animal skin at concentrations ranging from 7.5% to 10%; one study did find moderate irritation in rabbit skin at a concentration of 7.5%. Clinical tests at a concentration of 10.4% confirmed the absence of significant irritation in humans. An ocular toxicity study in rabbits found no toxicity. No evidence of genotoxicity was found in either a mammalian test system or in the Ames test system, with or without metabolic activation. The available data on Octyldodecyl Stearoyl Stearate and the previously considered data on long-chain alcohols and fatty acids, however, did not provide a sufficient basis to make a determination of safety. Additional data needs include (1) chemical properties, including the octanol/water partition coefficient; and (2) if there is significant dermal absorption or if significant quantities of the ingredient may contact mucous membranes or be ingested, then reproductive and developmental toxicity data may be needed. Until such time as these data are received, the available data do not support the safety of Octyldodecyl Stearoyl Stearate as used in cosmetic formulations.

Final report on the safety assessment of Stearamide DIBA-Stearate.

Stearamide DIBA-Stearate is a substituted dihydroxyisobutylamine (DIBA) that functions in cosmetic formulations as an opacifying agent, a surfactant-foam booster, and a viscosity increasing agent. Stearamide DIBA-Stearate was reportedly used in four cosmetic formulations, at concentrations of 1% to 3%. Few data on this ingredient were available. Data on related ingredients, including Dibutyl Adipate, Diisopropyl Adipate, Stearamide DEA, and Stearamide MEA, were considered in the assessment of safety. A formulation containing 1.3% Stearamide DIBA-Stearate (further diluted to 4% of the formulation) was mildly irritating but nonsensitizing in an repeated-insult patch test (RIPT). The same dilution was noncomedogenic. At a concentration of 20%, Dibutyl Adipate had an oral LD50 of 2 g/kg. Subchronic dermal exposure of rabbits (1.0 ml/kg/day) caused a reduction in weight gain that was not observed at a dose of 0.5 ml/kg/day. In studies using rabbits, undiluted Dibutyl Adipate caused mild to moderate skin irritation and minimal ocular irritation. When pregnant rats were treated intraperitoneally with approximately 1.75 ml/kg Dibutyl Adipate during gestation, the incidence of fetal gross abnormalities was increased. No effect was observed at smaller doses. Diisopropyl Adipate had low acute oral and percutaneous toxicity, and was only a very mild ocular irritant. In skin irritation studies using rabbits, 5.0% to 100% Diisopropyl Adipate caused minimal to mild irritation; these results were also seen in clinical testing with only moderate cumulative irritation, and no sensitization or photosensitization. A formulation containing 5.27% Stearamide MEA was not toxic to rats when applied topically daily for 13 weeks. In studies using rabbits, Stearamide DEA (35% to 40%) was not a skin or ocular irritant, and Stearamide MEA (5.27%) was not an ocular irritant. At 17%, Stearamide MEA was not irritating to the skin, but caused minimal to moderate irritation to the eyes of rabbits. Stearamide MEA (5.27%) did not cause sensitization during a clinical study. It was not possible, however, to determine the relevance of these data on related ingredients. Therefore, it was concluded that the available data are insufficient. Additional data needs are (1) method of manufacture; (2) chemical characterization, including impurities; (3) dermal absorption; if significantly absorbed, then a 28-day dermal toxicity study and a reproductive and developmental toxicity study may be needed; (4) two genotoxicity assays, at least one in a mammalian system; if positive, then a 2-year dermal carcinogenesis study using National Toxicology Program (NTP) methods may be needed; (5) ultraviolet (UV) absorption data; if significant absorption occurs in the UVA or UVB range, photosensitization data are needed. Absent these data, it was concluded that the available data are insufficient to support the safety of Stearamide DIBA-Stearate as used in cosmetic products.

Unexpected skin barrier influence from nonionic emulsifiers.

Skin disorders are often treated with creams containing various active substances. The creams also contain emulsifiers, which are surface-active ingredients used to stabilize the emulsion. Emulsifiers are potential irritants and in the present study the influence of stearic acid, glyceryl stearate, PEG-2, -9, -40, and -100 stearate, steareth-2, -10 and -21 on normal as well as on irritated skin have been evaluated with non-invasive measurements. Test emulsions were created by incorporating 5% emulsifiers in a water/mineral oil mixture (50:50). The emulsions and their vehicle were then applied to normal skin for 48 h and to sodium lauryl sulfate (SLS) damaged skin for 17 h in aluminum chambers. Twenty-four hours after removal of the chambers the test sites were evaluated for degree of irritation. In normal skin, the emulsifiers induced significant differences in TEWL but not in skin blood flow. Five of the emulsifiers increased TEWL. In SLS-damaged skin an aggravation of the irritation was expected. However, no differences regarding skin blood flow was noted from the emulsifiers. Furthermore, three emulsifiers unexpectedly decreased TEWL. These results highlight the possibility of absorption of these emulsifiers into the lipid bilayer, which increase TEWL in normal skin and decrease TEWL in damaged skin.

Some unusual complications of myelography and lumbosacral radiculography.

In 570 patients an examination of the subarachnoideal space was performed. In 77 of them oily contrast media, in 93 oxygen and in the remaining 400 patients different water-soluble contrast media were used, including Conray 60, Dimer X and Amipaque. Neurotoxic spinal complications occurred in 12 of the 400 patients investigated with hydrosoluble agents (i.e. in 3%). In one of them after investigation with Dimer X, intense cramps in the lower extremities caused a fracture of the femoral neck within a few hours after the investigation. In another patient, investigated with Amipaque, a psychotic reaction with amentia and paranoid symptoms developed, which disappeared completely after 4 days.