How irritant are n-propanol and isopropanol? - A systematic review.

BACKGROUND: The use of alcoholic-based hand rubs (ABHRs) is an important tool for hand hygiene, especially in times of the COVID-19 pandemic. Possible irritant effects of ABHR may prevent their use by persons at risk of infection. METHODS: This systematic review is based on a PubMed search of articles published between January 2000 and September 2019 in English and German, and a manual search, related to the irritation potential of alcohol-based disinfectants restricted to n-propanol (1-propanol) and its structural isomer isopropanol (isopropyl alcohol, 2-propanol). RESULTS: The majority of the included studies show a low irritation potential of n-propanol alone. However, recent studies provide evidence for significant barrier damage effects of repeated exposure to 60% n-propanol in healthy, as well as atopic skin in vivo. The synergistic response of combined irritants, (ie, a combination of n-propanol or isopropanol with detergents such as sodium lauryl sulfate) is greater, compared with a quantitatively identical application of the same irritant alone. CONCLUSION: While recent studies indicate a higher risk of skin irritation for n-propanol and isopropanol than reported in the past, this risk still seems to be lower than that for frequent handwashing with detergents, as recommended by some to prevent COVID-19 infections.

Contact Dermatitis from Hand Hygiene Practices in the COVID-19 Pandemic.

Coronavirus disease 2019 (COVID-19) pandemic continues to spread globally at a staggering speed. At present, there is no effective treatment or vaccine for COVID-19. Hand disinfection is a cost-effective way to prevent its transmission. According to the Centres for Disease Control and Prevention (CDC) guidelines, we should wash our hands with soap and water for at least 20 seconds. If soap and water are not readily available, alcohol-based hand rubs (ABHRs) with at least 60% alcohol are the alternative. With diligent hand disinfection reinforced during COVID-19, there is an increased prevalence of contact dermatitis. This commentary highlights the fact that contact dermatitis is a readily treatable condition and should not cause any deviation of proper hand hygiene. In irritant contact dermatitis (ICD), the management strategies are selection of less irritating hand hygiene products, frequent use of moisturisers to rebuild the skin barrier, and education on proper hand hygiene practices. In allergic contact dermatitis (ACD), the identification and avoidance of the contact allergen is the key to treatment. However, ACD is less common and only accounts for 20% of the cases. The identified allergens in hand cleansers are predominantly preservative excipients and ACD attributable to ABHR are very uncommon. Alcohol-free hand rubs are widely available on the market but it is not a recommended alternative to ABHRs by the CDC.

Barrier damaging effects of n-propanol in occlusion-modified tandem repeated irritation test: Modulation by exposure factors and atopic skin disease.

BACKGROUND: Recent studies provide evidence for significant and previously underestimated barrier damaging effects of repeated exposure to 60% n-propanol in healthy skin in vivo. OBJECTIVES: To investigate further the cumulative effects of a range of n-propanol concentrations relevant at the workplace in healthy and atopic dermatitis (AD) individuals, and study the modulation of the outcomes by co-exposure and host-related factors. METHODS: Healthy adult and AD volunteers were exposed to n-propanol concentrations from 30% to 75% in occlusion-modified tandem repeated irritation test with measurements of erythema, transepidermal water loss, capacitance, and the natural moisturizing factor (NMF) levels at baseline and after 96 hours. RESULTS: n-Propanol exerted significant barrier damaging effects even at the lowest concentration in both groups. Exposure to all n-propanol concentrations significantly reduced the NMF levels. Preceding low-grade trauma by occlusion/water exposure reduced the skin irritation threshold in both groups. The differences in the severity of the barrier function impairment after exposure to the same concentrations under the same conditions between the AD and control groups were significant. CONCLUSIONS: The negative effects of cumulative exposure to n-propanol in healthy and atopic skin shown in the study suggest the need for critical re-evaluation of its irritant properties in vivo.

Barrier Function and Natural Moisturizing Factor Levels After Cumula-tive Exposure to Short-chain Aliphatic Alcohols and Detergents: Results of Occlusion-modified Tandem Repeated Irritation Test.

Alcohol-based disinfectants and detergents are common workplace factors for irritant contact dermatitis (ICD). Though occlusion and water are relevant co-exposures, the tandem effects of occlusion and sequential exposure to alcohols and detergents have not been studied. We therefore investigated the combined effects of occlusion with water and repeated exposure to n-propanol and/or sodium lauryl sulphate (SLS) in an occlusion-modified tandem irritation test. The outcomes included visual scoring, measurement of erythema, transepidermal water loss, capacitance and natural moisturizing factor (NMF) levels. Occlusion abrogated the skin barrier function and significantly enhanced the irritant-induced barrier damaging effects. The NMF levels of all irritant-exposed fields decreased significantly compared with the non-exposed fields; occlusion enhanced the decrease in NMF. Although SLS exerted more pronounced effects on the measured parameters, the barrier function impairment and NMF decrease after exposure to n-propanol in workplace-relevant concentrations, found in the study, confirm the significance of short-chain aliphatic alcohols for occupational ICD.

Metabolites of Aliphatic Alcohols Detected in Alcoholic Beverages Inhibit Phagocytosis.

AIMS: The aim of our study was to measure granulocyte and monocyte phagocytosis following treatment of cells with some metabolites of aliphatic alcohols alone and in combination with acetaldehyde. METHODS: The cells were separated from human peripheral blood prior to determination of phagocytosis of opsonized zymosan particles by granulocytes and monocytes treated individually with metabolites of aliphatic alcohols including formaldehyde, 1-propanal, acetone, 1-butanal, and 2-butanone and in combination with acetaldehyde. RESULTS: The findings revealed that metabolites of aliphatic alcohols inhibited phagocytosis by granulocytes and monocytes in a concentration-dependent manner and when combined with acetaldehyde, they caused a further decrease in phagocytic activity. CONCLUSION: Due to their additive effects, it is possible that, in combination with acetaldehyde, metabolites of aliphatic alcohols may inhibit phagocytosis at physiologically realistic concentrations in episodic heavy drinkers, thereby contributing to their increased susceptibility to infectious diseases.

Effect of disinfectants on glucose monitors.

BACKGROUND: Monitoring blood glucose levels is an integral part of routine diabetes management. To minimize the risk of transmission of bloodborne pathogens during monitoring, the Centers for Disease Control and Prevention (CDC) recommends that glucose meters be disinfected after each use whenever they are used to test multiple patients. The objective of this study is to assess the compatibility of some common disinfectants with certain blood glucose meter systems. METHODS: We tested six disinfectants for adverse impact on meter performance or the exterior meter surfaces. The disinfectants tested were 0.525% sodium hypochlorite, 20% 2-propanol and 10% ethanol, 17.2% isopropanol, 55% isopropanol, 70% isopropanol, and hydrogen peroxide. To assess meter performance, we tested OneTouch® Ultra® blood glucose monitoring systems with control solution before and after application of either water or disinfectant. To assess the effect on exterior meter surfaces, we performed a soaking test to simulate long-term exposure to disinfectant. RESULTS: Paired t-test results showed that the control solution data associated with disinfectant and with water application were not significantly different for each meter type. However, most of the meter types were adversely affected by hydrogen peroxide and/or by the higher concentrations of alcohol-based disinfectants. CONCLUSIONS: Although none of the six disinfectants affected meter performance, hydrogen peroxide and isopropanol >20% adversely affected the exterior surfaces of the tested meters. When complying with CDC instructions for meter disinfection, users should use caution and choose disinfectants that have been validated by the meter manufacturer.

[Drug-induced pneumonitis in a patient treated with venlafaxine and propanolol]. / Pneumopathie médicamenteuse sous traitement par venlafaxine et propranolol.

INTRODUCTION: Venlafaxine and propranolol have rarely been identified as causes of pulmonary pathology. We describe a case of drug-induced pneumonitis occurring in a patient treated with these two medications. CASE REPORT: A 55 years old woman with liver cirrhosis treated with venlafaxine for 1 year and propranolol for 1 month was admitted to the intensive care unit because of acute respiratory failure. A Mycoplasma pneumoniae pneumonitis was diagnosed. After initial improvement under antibiotics, a new deterioration of respiratory status was observed 4 days after the reintroduction of venlafaxine and propranolol. Spontaneous recovery occurred after these treatments were withheld. Co administration of venlafaxine and propranolol, 2 drugs with affinity for the same cytochrome P450 isoenzyme (CYP2D6), may have contributed to drug accumulation and pulmonary toxicity. The liver cirrhosis of our patient may also have contributed to decreased cytochrome P450 enzymatic activity. CONCLUSIONS: Venlafaxine and propranolol share the same metabolic pathway and their co-administration may be complicated by drug induced pneumonitis.

The irritant potential of n-propanol (nonanoic acid vehicle) in cumulative skin irritation: a validation study of two different human in vivo test models.

BACKGROUND/PURPOSE: Human in vivo cumulative irritation tests with low-grade irritants simulate real-life exposure to skin irritants. The test outcome depends not only on the substance tested but also on the design of the assay. More than one experimental irritant is usually used because chemicals have diverse mechanisms of action on the skin. We used sodium lauryl sulfate (SLS) and nonanoic acid (NON) in three different concentrations plus their vehicles, water and n-propanol, respectively, to validate our test models and to optimize test concentrations. METHODS: Healthy volunteer forearm skin was exposed in two different cumulative test models: a repeated open model (ROAT) and an exaggerated wash test model. ROAT: 10-min daily exposures for 5+4 days (no irritation on weekend) to SLS 0% (water), 0.5%, 1.0% and 2.0% on the right arm and NON 0% (n-propanol neat), 10%, 20% and 30% on the left arm. Wash test: induction of irritation by three daily washings for 6 days and maintenance of the dermatitis by two daily washings for 12 days with SLS 0%, 5%, 10% and 15% or NON 0%, 30%, 40% and 50%. Reactions were evaluated clinically and instrumentally (transepidermal water loss, colorimetry and hydration) at sequential time points. Additionally, for the wash test, subjective pain scores were obtained from the volunteers. RESULTS: In the ROAT, n-propanol exhibited irritation potential at the level of SLS 1.0% and, by visual scoring, was only found to be significantly different from the two highest concentrations of NON (20% and 30%). In the wash test, n-propanol was much less irritating than SLS, and it could only be distinguished statistically from NON (any concentration) by visual reading. For both test models, n-propanol, by instrumental measurements, was not significantly different from any NON concentration. CONCLUSION: In cumulative irritation test assays, n-propanol appears to be quite irritant itself and may thus be a significant contributor to NON irritation. Moreover, n-propanol was more irritant in the ROAT compared with the wash test.

Dermal tolerance of Sterillium, a propanol-based hand rub.

Alcohol-based hand rubs have been used for hygienic hand disinfection in hospitals for decades. In order to achieve good compliance with hand hygiene practices in the healthcare setting, dermal tolerance of a hand rub product is crucial. Sterillium, which is used in many European countries for hygienic hand disinfection, is based on iso-propanol, n-propanol and mecetronium etilsulphate. The potential for dermal irritation and sensitization of commercially available propanol-based hand rubs containing emollients has not been studied systematically. We therefore studied the dermal tolerance of Sterillium in a repetitive occlusive patch test on 55 subjects. Sterillium was applied to one site on the back under an occlusive patch during an induction phase (total of nine applications over a three-week period) and two weeks later to a virgin site on the back during a challenge phase (one application). Twenty-four hours after removal of the patches (induction phase and challenge phase), and in addition, after 48 and 72 h (challenge phase), the sites were graded for skin reactions using a standardized scoring scale. In the induction phase, two of the 55 subjects had a barely perceptible minimal erythema at one of nine time points. The remaining 53 subjects had no skin reaction at any time. In the challenge phase, all 55 subjects had no skin reaction at all. The absence of significant reactions with respect to severity and frequency demonstrates the favourable dermal tolerance of the hand rub product. The lack of irritation or sensitization potential could enhance compliance with hand hygiene among healthcare workers.

Pharmacokinetics of propranolol after single and multiple dosing with sustained release propranolol or propranolol CR (innopran XL) , a new chronotherapeutic formulation.

Blood pressure rises rapidly upon waking and may be responsible, in part, for the increased incidence of myocardial infarction and stroke during the morning hours. Current formulations and dosing of antihypertensive drugs do not provide maximum coverage during this vulnerable period. This study was performed to demonstrate that propranolol CR (Innopran XL), a novel chronotherapeutic formulation of propranolol designed for nighttime dosing, has appropriate pharmacokinetics to provide maximum cardioprotective effect in the morning. Pharmacokinetics of propranolol CR and sustained-release propranolol after single and multiple doses were determined in normal male volunteers in this open-label, 2-period crossover study. The drugs were dosed in the evening and serial blood samples were taken for determination of propranolol concentration the next 24 to 72 hours. After a single 160-mg dose of propranolol CR administered at 10 pm, absorption was delayed by about 4 hours, after which plasma concentration rose steadily, reaching a peak at about 10:00 am. In contrast, after dosing with sustained release propranolol, plasma levels of propranolol began to rise almost immediately, reaching a plateau between 4:00 am and 10:00 am. During multiple dosing, steady-state trough plasma concentrations were achieved after 2 days with either drug. After the final dose, the plasma profiles of both drugs were similar to those observed in the single-dose study. Bioavailability was similar for both formulations of propranolol. Propranolol CR exhibited appropriate pharmacokinetics for a chronotherapeutic approach to the treatment of hypertension.

Deformidades peneanas: enfermedad de la Peyronie / Deformities of the penis: Peyronie´s disease

La enfermedad de la Peyronie es un endurecimiento de los cuerpos cavernosos del pene, que provoca incurvación y una serie de complicaciones en el paciente que van desde un intenso dolor a trastornos de la función sexual. Pese a ser una patología conocida desde la antigüedad, descrita por primera vez en 1704, la etiopatogenia sigue siendo desconocida. Como consecuencia del desconocimiento de la etiopatogenia sigue siendo desconocida. Como consecuencia del desconocimiento de la etiopatogenia de la enfermedad, los tratamientos van cambiando constantemente aunque no se ha demostrado hasta ahora la efectividad de un tratamiento específico (AU)

Irritancy of the skin disinfectant n-propanol.

Hand disinfection with short-chain aliphatic alcohols, so-called "rub-ins" is the method of choice for cross-infection prevention in health care environments, but their irritant potential is not well known. Skin tolerance is a major compliance factor, and a high proportion of health care workers suffer from low-grade irritant contact dermatitis. Therefore, assessment of the irritancy of the skin disinfectant n-propanol 60%, and comparative 100% and 0% solutions, was performed in the setting of experimental low-grade ICD. ICD was induced by overnight patch exposure to H2O, and to 0.3% sodium dodecyl sulfate (SDS), in 12 probands, followed by repeated open exposure to the test substances. Outcome variables were transepidermal water loss (TEWL), and skin surface capacitance. On skin sites pre-irritated by SDS, all n-propanol concentrations (100%, 60%, 0%) increased TEWL. However, a clear divergence appeared between pure n-propanol, and the lower concentrations. In contrast to pure n-propanol, n-propanol 60% and 0% had no significant effect on TEWL on H2O-pre-irritated skin sites. Capacitance of pre-irritated skin sites was increased by exposure to H2O-containing n-propanol solutions (60% and 0%). These results show a clear difference between the irritant potential of n-propanol 100% on one side, and n-propanol 60% and 0% on the other side. The level of pre-existent skin irritation is a pertinent factor in susceptibility to irritation, as the irritant potential of n-propanol 60%, the concentration used in daily practice, and n-propanol 0% (water) became significant only on detergent-irritated skin. Thus, preventive skin care may be a constructive approach in increasing tolerance of modern hand disinfection practices.

Tandem application of sodium lauryl sulfate and n-propanol does not lead to enhancement of cumulative skin irritation.

Irritant contact dermatitis has a broad spectrum of clinical features and is a leading cause of occupational disease worldwide. It has been shown previously that a combination of chemically different irritants may cause an additive effect compared to single application of these substances. In this study, tandem application of sodium lauryl sulfate and n-propanol was investigated in 20 human volunteers using non-invasive bioengineering methods, such as measurement of transepidermal water loss and chromametry. N-propanol did not enhance cumulative skin irritation when used with sodium lauryl sulfate, as has been reported for toluene. As n-propanol is the active ingredient in many disinfectants, this is of particular interest regarding occupational skin irritation in health care workers.

Inhibition of human peripheral blood neutrophil respiratory burst by alcohol-based venipuncture site disinfection.

Ethanol inhibits the respiratory burst of neutrophils. Therefore, the effects of alcohol-based skin disinfection on oxygen metabolism in neutrophils were tested using 70% ethanol or an ethanol-isopropanol-n-propanol mixture. Neutrophil respiratory burst activity as assessed fluorometrically by oxidation of 2', 7'-dichlorofluorescein diacetate increased at 10 min after disinfection with 70% ethanol compared to the activity at 30 s. The increase was significant for triggering oxidative burst with formyl-peptide but not with phorbol myristate acetate.

Structural damage to Schiotz tonometers after disinfection with solutions.

Although Schiotz tonometry has been long ago replaced by Goldmann applanation tonometry measurement of intraocular pressure, it remains a viable clinical technique in nursing homes and other "out of office" settings. Because Schiotz tonometers come into contact with the cornea and tear film, they must be properly disinfected to prevent cross-infection with HIV and other infectious pathogens. The Centers for Disease Control and Prevention (CDC) recommends that all eye contact devices be disinfected by a 5- to 10-min soak in one of following disinfectants: 3% hydrogen peroxide, 1:10 sodium hypochlorite (household bleach), or 70% isopropyl alcohol. The effects of these disinfectants on Schiotz tonometers have not been previously investigated. This study investigated the effects of CDC-recommended disinfectants on the structural integrity of Schiotz tonometers. The results of the study indicated that soaking in 1:10 sodium hypochlorite and 3% hydrogen peroxide damaged Schiotz tonometers and rendered them inoperable. Alcohol caused minor damage to the tonometer and was the safest of the CDC disinfectants. This study showed there is limited application of CDC infection control criteria to Schiotz tonometers due to the extensive corrosion and damage caused by hydrogen peroxide and bleach.

Natural ingredients based cosmetics. Content of selected fragrance sensitizers.

In the present study, we have investigated 42 cosmetic products based on natural ingredients for content of 11 fragrance substances: geraniol, hydroxycitronellal, eugenol, isoeugenol, cinnamic aldehyde, cinnamic alcohol, alpha-amylcinnamic aldehyde, citral, coumarin, dihydrocoumarin and alpha-hexylcinnamic aldehyde. The study revealed that the 91% (20/22) of the natural ingredients based perfumes contained 0.027%-7.706% of 1 to 7 of the target fragrances. Between 1 and 5 of the chemically defined synthetic constituents of fragrance mix were found in 82% (18/22) of the perfumes. 35% (7/20) of the other cosmetic products (shampoos, creams, tonics, etc) were found to contain 0.0003-0.0820% of 1 to 3 of the target fragrances. Relatively high concentrations of hydroxycitronellal, coumarin, cinnamic alcohol and alpha-amyl cinnamic aldehyde were found in some of the investigated products. The detection of hydroxycitronellal and alpha-hexylcinnamic aldehyde in some of the products demonstrates that artificial fragrances, i.e., compounds not yet regarded as natural substances, may be present in products claimed to be based on natural ingredients.