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Antimicrobial efficacy of caprylyl glycol and ethylhexylglycerine in emulsion
Abstract
Antimicrobial efficacies of caprylyl glycol and ethylhexylglycerin in an emulsion were evaluated by USP24-NF19. The minimum concentration of caprylyl glycol and ethyl- hexylglycerin inhibited Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans within 1 day and Aspergillus niger within 28 days was 0.5% and 1.5%, respectively. The 1:3 mixture ratio of the caprylyl glycol and ethylhexylglycerin was chosen for further steps on inhibitory effect towards those prohibited microbial in cosmetics by evaluation at the concentration of 0.5%, 1.0%, 1.5% and 2.0%, respectively. It was found that the minimum concentration inhibited S. aureus within 3 days, E. coli, P. aeruginosa and C.albicans within 1 day and A. niger within 28 days was 1.0%. This developed preservative system offers multifunctional cosmetic ingredients in addition to their emollient efficacies.
... Caprylyl glycol is a diol that can act as an antimicrobial agent in cosmetic formulations due to its ability to destabilize the bacterial cell membrane. In the skin, it acts as a conditioning, emollient agent, filling the spaces between the corneocytes and making the skin softer, and as a humectant, attracting water molecules to the upper layers of the skin without generating hypersensitivity or irritation in humans (2,3,4,16,17). ...
... O caprilil glicol é um diol que nos cosméticos pode atuar como antimicrobiano, devido a sua capacidade de desestabilizar a membrana celular bacteriana, e na pele age como agente condicionador, emoliente, preenchendo os espaços entre os cornócitos e tornando a pele mais macia, e umectante, atraindo as moléculas de água para as camadas superiores da pele, sem gerar hipersensibilidade ou irritação em humanos (2,3,4,16,17). ...
... The decreased TEWL in the areas treated with formulations including caprylyl glycol or hyaluronic acid can also be explained by their humectant activity (10,12). Those components attract water molecules to the skin surface (3,4,10,12,16,17,27), where they form an emulsion with skin lipids and sweat components, decreasing TEWL (27). ...
Cosmetic films are structures made of a polymer capable of forming a continuous matrix. Collagen and hyaluronic acid (HA) are components of the skin extracellular matrix and act to maintain its elasticity and resistance. Ascorbic acid (AA) acts in the formation of collagen fibers, contributing to the maintenance of their firmness and elasticity. This study aimed to evaluate the moisturizing properties of cosmetic films with AA or HA in their composition. It was also investigated whether the presence of caprylyl glycol would interfere with the TWEL of the formulations. The occlusive properties of the films were assessed based on the reduction of transepidermal water loss (TEWL) in 20 healthy participants using a Tewameter probe. At T30, 30 minutes after application, all formulations showed a reduction in TEWL compared to the control. In general, the formulations that included caprylyl glycol presented the best TEWL results after 30 min of application. However, after 60 minutes, the transepidermal water loss began to return to its basal levels. This study showed a significant difference in the TEWL value, suggesting that the topical application of the films can contribute to the improvement and maintenance of skin hydration. Keywords: cosmetic films; collagen; hyaluronic acid; ascorbic acid; skin barrier
... Caprylyl glycol은 양친매성 물질로, 다른 보존제의 항균 력 증가에 도움을 주는 것으로 알려져 있다. 단독으로는 항균효 과가 미미하며, ethylhexylglycerin 등과 함께 혼합하여 사용한다 (Lawan et al., 2009;Varvaresou et al., 2009;Ziosi et al., 2013 (Lawan et al., 2009;Varvaresou et al., 2009 (Finnegan & Percival, 2015;Qiu et al., 2011;Siegert, 2014 ...
... Caprylyl glycol은 양친매성 물질로, 다른 보존제의 항균 력 증가에 도움을 주는 것으로 알려져 있다. 단독으로는 항균효 과가 미미하며, ethylhexylglycerin 등과 함께 혼합하여 사용한다 (Lawan et al., 2009;Varvaresou et al., 2009;Ziosi et al., 2013 (Lawan et al., 2009;Varvaresou et al., 2009 (Finnegan & Percival, 2015;Qiu et al., 2011;Siegert, 2014 ...
Purpose: To minimize the use of preservatives in cosmetics, the cosmetic industry has attempted to use alternative preservatives that can function as skin conditioning agents and possess antimicrobial effects. In this study, the antimicrobial synergistic effects of 1,2-hexanediol, ethylhexylglycerin, and caprylyl glycol, which are used as alternative preservatives in cosmetics, with various chelating agents were investigated.Methods: Changes in the antimicrobial activity of the preservatives against gram-positive bacteria, gram-negative bacteria, and yeast were examined. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of these agents when used alone were confirmed, and the synergistic effects were confirmed by combining alternative preservatives and chelating agents through a checkerboard assay.Results: The MIC and MBC results confirmed the antimicrobial effects exerted by the alternative preservatives on all strains (Staphylococcus aureus, Escherichia coli, and Candida albicans) at concentrations of ≤2%. The chelating agent exhibited excellent MIC results with 0.06% disodium EDTA and 0.03% tetrasodium EDTA in S.aureus and a relatively high MBC was observed with tetrasodium EDTA 0.25%. The checkerboard assay results demonstrated a synergistic effect against all strains, and the combination of ethylhexylglycerin and tetrasodium EDTA was determined to be easy to control all strains at concentrations that were 2–25 times lower than that of ethylhexylglycerin alone.Conclusion: Antimicrobial synergistic effects were confirmed for combinations of three alternative preservatives and six chelating agents. The selective use of alternative preservatives and appropriate chelating agents can reduce the amount of alternative preservatives used which could benefit the cosmetic industry in terms of reducing skin irritation and stability.
... 1,2-Decanediol exhibits a more powerful antimicrobial activity, but it is not likely to be soluble in water. (S)-3-Butoxypropane-1,2-diol and (S)-3-(hexyloxy)propa ne-1,2-diol that have similar chemical structures to 1,2-alkanedi ols also exhibited similar antimicrobial activities to 1,2-hexane diol and 1,2-octanediol, respectively [12]. In particular, they do not need higher cost as much as 1,2-alkanediols with straight alkyl chains because they can be obtained easily from glycerol. ...
... In the case of (S)-3-(hexyloxy)propane-1,2-diol, there were four preferred conformers g 0 G 0 TTTG 0 G 0 TTt, g 0 G 0 TTTG 0 TTTt, g 0 G 0 TTTGGTTt, and gG 0 GTTTGTTg 0 with DG = 0.00 (30.5%), 0.29 (18.5%), 0.33 (17.5%), and 0.37 (16.4%) kcal/mol, respectively. The first three conformers had in common a bifurcated H-Bond of the O 12 ...
... In the present study, ethylhexylglycerin was detected in 23 infant products and 2 products for sensitive skin with concentrations ranged between 0.0079-0.55%, at which when used in combination with phenoxyethanol, glycols, or methylparaben, ethylhexylglycerin has proven to significantly enhance the antimicrobial activity of those preservatives [39][40][41][42] . This preservative boosting action of ethylhexylglycerin has been attributed to its surfactant-like structure, which allows more preservatives to penetrate through cell membrane. ...
The present study aims to investigate the current trends in replacing conventional preservatives with multifunctional ingredients with antimicrobial properties for preservation of cosmetics for infants or sensitive population, to decrease their potential for contact dermatitis. We first reviewed the labels of cosmetics purchased from the Chinese market for conventional preservatives and multifunctional ingredients with antimicrobial properties, of which the actual contents were further quantified by chromatographic methods. We identified 7 traditional preservatives (phenoxyethanol, benzoic acid (salts), methylparaben, benzyl alcohol, sorbic acid (salts), propylparaben, and methylisothiazolinone), and 11 alternative ingredients with antimicrobial activities (ethylhexylglycerin, butylene glycol, caprylyl glycol, propylene glycol, 1,2-hexanediol, p-anisic acid, hydroxyacetophenone, pentylene glycol, decylene glycol, caprylhydroxamic acid, and aminomethyl propanol) in descending order of prevalence. The contents of all identified preservatives and ingredients were either below regulatory limits or in the range that is generally regarded to be safe. Further challenge with microorganisms indicated irrespective of the composition of preservation systems, product preservation could be compromised under test conditions. We conclude that multifunctional ingredients with antimicrobial properties in cosmetics have the potential to completely replace or significantly reduce the use of traditional preservatives while retaining comparative preservative efficacy. Future attentions may need to be shifted to the safety of those multifunctional ingredients with antimicrobial properties.
... The major purpose of preservatives in cosmetics is to ensure the antimicrobial effectiveness of that particular product [34]. According to Lawan et al. [35], EHG was reported to have antimicrobial activity against S. aureus, P. aeruginosa, E. coli, and C. albicans. At a concentration of 1.5%, this substance was able to inhibit the growth of these tested organisms and lasted up to one day. ...
Cutibacterium acnes, Staphylococcus epidermidis, and Staphylococcus aureus are commonly associated with the pathogenesis of acne vulgaris. Skincare products that contain natural ingredients have become a trend to treat acne. Dr.Ridz Anti-Acne Nanoserum® product was formulated with the extract of Cassia alata leaf and Piper betle. The aim of this study was to determine the antibacterial activity of this formulated product against against C. acnes, S. epidermidis, and S. aureus. The minimum inhibitory concentration (MIC) value and the minimum bactericidal concentration (MBC) were determined using a broth microdilution and a streak plate method, respectively. The rate of killing by this product was tested using time-kill assay (TKA) at 0.5x MIC, 1x MIC, and 2x MIC with incubation periods of 2, 4, 6, 8 10, 12, and 24 hours. The MIC values showed that this product inhibited S. epidermidis and S. aureus better than C. acnes. From the calculation of the MBC/MIC ratio, this product showed bactericidal effects against all tested bacteria. The time-kill studies showed that the killing effect of this product was concentration-dependent, and the highest antibacterial activity was observed at the concentration of 2x MIC against all tested bacteria. In conclusion, Dr.Ridz Anti-Acne Nanoserum® exhibits the best antibacterial activities against S. epidermidis and showed a bactericidal effect towards all tested bacteria.
... Climbazole is an imidazole anti-fungal agent and exerts its anti-fungal effects by inhibiting the synthesis of ergosterol, a major component in fungal plasma membranes [9]. Caprylyl glycol, apart from its humectant effects, which aids in scalp moisturizing, has also shown to have anti-microbial properties and it disrupts the cell membrane of fungi [10]. This amalgamation of anti-microbial compounds is a novel combination that is meant to target the Malassezia species in a multi-prong manner for greater efficacy. ...
Dandruff is a common scalp condition affecting almost half of the world's population. Despite its high prevalence, the exact pathophysiology is not well established and is understood to be multifactorial, with factors such as fungal colonisation, sebaceous gland activity and individual factors being implicated. There is a need for an effective and safe shampoo that can target the above factors. Hence, we have developed a shampoo formulation with properties of oil control, moisturising, non‐irritative, anti‐fungal, anti‐microbial, and itch relieving.
In this interventional, open‐label study, we evaluated the efficacy and safety of this shampoo in reducing the clinical signs of dandruff and pruritus in patients with pre‐existing mild to moderate dandruff over a course of 21‐day treatment duration through self‐assessment and objective clinical evaluations.
After continued use of the shampoo, there was a significant decrease in the adherent and loose scalp flaking scores. Mean pruritus scores also decreased significantly across the 21‐day time points. There were also no adverse events or skin intolerances reported.
This study showed that our shampoo formulation has led to significant reduction in both adherent and loose scalp flaking and pruritus when used in individuals suffering from mild to moderate dandruff. As such, it is an ideal shampoo which can be used to effectively control dandruff.
... Glyceryl caprylate is known as multifunctional and acts as a natural preservative, but also as an emollient, emulsifier, and skin penetration enhancer [56,57]. The substance has a good effect on numerous bacteria, yeasts, and molds [58,59]. No evidence of pro-oxidant behavior could be found. ...
Preservatives are typically used to protect cosmetic products from microbial spoilage. However, there is evidence that some preservatives can increase oxidation in O/W emulsions. This could have disadvantages for product quality, efficacy, and consumer health and well-being. Therefore, the impact of preservatives or multifunctionals on oxidation should be quantified. For this purpose, five O/W emulsions with different preservatives were prepared and stored. During storage, the oxygen concentration in the headspace of the samples was studied. The samples showed significant differences in their oxygen uptake and daily oxygen consumption rate. Thus, the preservatives used in this study had an influence on oxidation.
... The minimum inhibition concentration (MIC) of caprylyl glycol to inhibit Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans within 1 day Aspergillus niger within 28 days was a concentration of 0.5%. Next, ethylhexylglycerin inhibited the same microorganisms in the same period at the minimum concentration of 1.5% (Lawan et al., 2009). ...
Wound healing spray was developed from keratin protein extracted from a chicken feather in the study. Keratin is the most abundant protein in epithelial cells. Keratin was proven for wound healing ability because it can activate the keratinocyte in the skin responsible for wound healing. However, keratin wound healing spray is new to the market and has the potential to heal the wound gentle and pain-free. This study synthesized the keratin wound healing spray from chicken feathers and determined the character of the keratin wound healing spray. Keratin protein was extracted from chicken feathers. The extracted keratin solution was concentrated to the desired concentration by a rotary evaporator. The wound healing spray was synthesized by mixing the desired antimicrobial agent with keratin solutions like manuka honey, Garcinia Mangostana L., caprylyl glycol, ethylhexylglycerin and propylene glycol at a concentration of 13.0 w/w%, 0.5 w/w%, 1.0 w/w%, 2.0 w/w% and 2.0 w/w%, respectively, and the characteristic was determined. The result has shown that the keratin protein is maintained in the wound healing spray after mixing with an antimicrobial agent according to the formulation from the FTIR result. The wound healing spray does not contain heavy metals like cadmium and lead. Still, copper, iron and zinc were present within the maximum daily level of vitamins and minerals for adults allowed in health supplements by the National Pharmaceutical Regulatory Division of Malaysia. The pH of the keratin wound healing spray was maintained at a pH of around 5.5. The density and the viscosity of the keratin wound healing spray were higher than the deionized water. In conclusion, the Keratin wound healing spray was synthesized, and it is safe for the consumer. The wound healing ability of the keratin wound healing spray needs to carry out the in vivo clinical test for future study.
... We also observe that PA-OCT released significantly more drug than PA 4020 . A possible explanation could be the ability of humectants such as caprylyl glycols (octanediol) to enhance antimicrobial efficacy of formulations [47,48]. Further study is warranted to fully elucidate the activity enhancing mechanism of FTP formulations. ...
The delivery of antimicrobial agents to surface wounds has been shown to be of central importance to the wound healing process. In this work, we prepared film forming wound care formulations containing 3 polymers (FTP) that provide broad-spectrum antimicrobial protection for prolonged periods. FTP formulations comprises of a smart gel matrix comprising of pH-degradable and temperature responsive polyacetals (smart polymer) which allow for the FTP films to be hydrophobic at room temperature, preventing accidental rubbing off, and hydrophilic at lower temperatures, allowing for easy removal. Two FTP smart-antimicrobial films were evaluated in this work: FTP-AgSD (Silver sulfadiazine actives), and FTP-NP (Neosporin actives). The in vitro and ex vivo antimicrobial efficacy studies show that FTP-AgSD films are significantly more effective for longer durations against Staphylococcus aureus (3 days), Candida albicans (9 days) and Pseudomonas aeruginosa (4 days) when compared to the cream formulations containing antimicrobials. FTP-NP films showed significantly improved antimicrobial activity for a minimum of 3 days for all pathogens tested. Moreover, when tested ex vivo in porcine skin, FTP-AgSD and FTP-NP showed average improvements of 0.89 log10 and 1.66 log10 respectively over standard cream counterparts. Dermal toxicity studies were carried out in a rat skin excision model which showed a similar wound healing pattern to that in rats treated with standard cream formulations as represented by reduction in wound size, and increase in wound healing markers.
... Additionally, it has been shown that chelating agents with different doses (0.1 and 0.2%) may have an additional boosting effect on 0.75% Euxyl® PE 9010 and reduce the quantity of preservatives required to adequately protect cosmetic formulations [57]. It was also showed that 1% mixture of ethylhexylglycerin and caprylyl glycol (3:1 ratio) inhibited growth of bacteria and fungi in cosmetic emulsion [53]. The combination of ethylhexylglycerin with caprylyl glycol is available on the market as Sensiva® SC 10 (Schülke Inc.) and offers new options for keeping cosmetic products microbiologically stable [56]. ...
This review reports cosmetic ingredients with antimicrobial activity including synthetic and natural (plant and microbial) origin as alternative for preservatives used in cosmetics as well described mechanism of their action.
... In addition, Nair et al. [30] reported that caprylic acid and monocaprylin could inactivate common mastitis pathogens, including S. agalactiae, S. dysgalactiae, S. uberis, S. aureus, and E. coli and potential as alternatives or adjuncts to antibiotics as intra-mammary infusion to treat bovine mastitis. Caprylic compound, such as caprylic glycol has been known about its antimicrobial activity against S. aureus, E. coli, P. aeruginosa, and C. albicans [31] . Pubmed [32] reported that lauric acid itself had no antibacterial activity, but its combination with gentamicin or imipenem was synergistic against methicillin-resistant S. aureus (MRSA). ...
Petung bamboo (Dendrocalamus asper) is one of the abundant bamboos in Indonesia. Its shoot is nutritious and its wood is used for housing. Meanwhile, the leaves have been used as traditional medicine for remedy diarrhea in animals. Therefore, this research was conducted to compare the antibacterial activity of leaf extracts against diarrheagenic Escherichia coli. The extracts were prepared using methanol, ethanol, and the mixture thereof at the ratio 1:1, followed by solvent evaporation, to obtain methanolic, ethanolic, and methanol-ethanolic extracts, respectively. The antibacterial activity of all extracts was assayed by well, disc diffusions and micro-dilution and their effect were compared to tetracycline as positive control. The well and disc diffusion results were not obvious, but micro-dilution assay showed that ethanolic extract of D. asper leaves with yield of 28.47±3.76% (w/w) was the most effective to inhibit all tested E. coli strains. The chemical identification using pyrolisis-GC/MS showed that fatty acids, together with esters, long chain alcohols, and aldehydes were the major compounds in ethanolic extract of D. asper leaves. Further research to improve the effectivity of ethanolic extract as antidiarrheal agent is necessary. Application of the semi pure extract to animal models is also important.-GC/MS, fatty acids. INTRODUCTION Bamboo, a group of large woody grasses belonging to the family Poaceae and subfamily Bambusoideae, is one of forest plants which has been used extensively, especially its shoot and wood. The shoot can be processed into various health foods and medicines [1,2] , while the wood contributes mainly to housing and furniture [3] . Using the wood in a big amount yields leaves in a big amount too. Utilization of bamboo leaves was reported by some previous research. The ash of bamboo leaves is potential for stabilizing lateritic soils in highway construction [4] Bioactive compounds are normally accumulated in all parts of plants, but their concentration varies according to the part of plants. The bark and leaves of neem (Azadirachta indica L.) and the leaves of Tulsi (Ocimum sanctum L.) possessed antibacterial activity against Bacillus subtilis and Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli .
... In addition, Nair et al. [30] reported that caprylic acid and monocaprylin could inactivate common mastitis pathogens, including S. agalactiae, S. dysgalactiae, S. uberis, S. aureus, and E. coli and potential as alternatives or adjuncts to antibiotics as intra-mammary infusion to treat bovine mastitis. Caprylic compound, such as caprylic glycol has been known about its antimicrobial activity against S. aureus, E. coli, P. aeruginosa, and C. albicans [31] . Pubmed [32] reported that lauric acid itself had no antibacterial activity, but its combination with gentamicin or imipenem was synergistic against methicillin-resistant S. aureus (MRSA). ...
Objectives
Mouthwashes, a cornerstone of oral and dental hygiene, play a pivotal role in combating the formation of dental plaque, a leading cause of periodontal disease and dental caries. This study aimed to review the composition of mouthwashes found on retail shelves in Turkey and evaluate their prevalence and side effects, if any.
Methods
The mouthwashes examined were sourced from the 5 largest chain stores in each district of Istanbul. A comprehensive list of the constituents was meticulously recorded. The research was supported by an extensive compilation of references from scholarly databases such as Google Scholar, PubMed, and ScienceDirect. Through rigorous analysis, the relative proportions of mouthwash ingredients and components were determined.
Results
A total of 45 distinctive variations of mouthwashes, representing 17 prominent brands, were identified. Amongst the 116 ingredients discovered, 70 were evaluated for potential adverse effects and undesirable side effects. The aroma of the mouthwash (n = 45; 100%), as welll as their sodium fluoride (n = 28; 62.22%), sodium saccharin (n = 29; 64.44%), sorbitol (n = 21; 46.6%), and propylene glycol (n = 28; 62.22%) content were the main undesireable features.
Conclusions
The limited array of mouthwashes found on store shelves poses a concern for both oral and public health. Furthermore, the intricate composition of these products, consisting of numerous ingredients with the potential for adverse effects, warrants serious attention. Both clinicians and patients should acknowledge the importance and unwarranted side effects of the compnents of the mouthwashes.
Objectives
Snow fungus or snow mushroom or white jelly mushroom (Tremella fuciformis ), the edible mushroom, was formulated into hand sanitizer in form of moisturizing alcohol‐based hand rubs (ABHR) gel.
Methods
The stable base ABHRs were developed. The preferred bases were incorporated with various concentrations of snow mushroom extract. The stable and preferred snow mushroom ABHR was moisturizing and sanitizing efficacies evaluated in 20 human volunteers in a comparison with its placebo.
Results
The stable hand sanitizer gel bases containing 66.5% of ethanol and 0.3% triclosan were developed and incorporated with the extract of snow mushroom polysaccharide. Of which, the preparations containing 10% of snow mushroom and 0.3% of gelling agent gained the highest preferences as assessed in 20 Thai volunteers. The snow mushroom hand sanitizer was proved to be none irritated in the same group of the volunteers as was the placebo. The snow mushroom gel significantly (P < 0.05) moist the skin better than the placebo at all time of the interval assessment until the end of the study at 180 min. The hand sanitizers were confirmed on their anti‐septic, at which the efficacies of the active and placebo ABHR were comparable (P = 0.90).
Conclusions
Snow mushroom ABHR gel with its confirmed moisturizing and sanitizing efficacies is presented. It is meetings with the recommendation on hand hygienic improvement to combat the infections of diseases spreading. The preparation can be frequency applied with its proved skin hydrating efficacy co‐contributes in a good condition of hand hygiene.
Abstract The aim of this work is to develop, optimize and characterize cold process emulsions that are stable at acidic pH. The main surfactant was selected according to the hydrophilic lipophilic balance (HLB) concept and surface tension, whereas polymers were selected by viscoelastic measurements and analytical centrifugation. It was showed that the inclusion of methyl vinyl ether/maleic anhydride copolymer crosslinked with decadiene (PVM/MA) increased the storage modulus (G') of the gels (23.9-42.1 Pa) two-fold and the droplet migration decreased from 3.66% to 0.95%/h. Cetrimide was selected as a preservative based on its microbiological results and additional contribution to the stability of the emulsions. Four emulsions were developed that differed by the co-emulsifier used (PEG-20 glyceril laurate and polyglyceryl-4-isostearate) and the glycol (2-methyl-2,4-pentanediol and ethoxydiglycol). Viscoelastic measurements and droplet size/microscopic analysis showed that the structure of PEG-20 glyceril laurate emulsion (η' = 76.0 Pa.s at 0.01 Hz and 32.9 ± 3.7 µm, respectively) was stronger compared to polyglyceryl-4-isostearate (η' = 37.4 Pa.s at 0.01 Hz and 37.8 ± 15.7 µm, respectively). Differential scanning calorimetry (DSC) results were in accordance with the latter and showed that PEG-20 glyceril laurate with 2-methyl-2,4-pentanediol corresponded to the strongest structure (|224.4| W °C g(-1)). This cold process allowed a total production savings of more than 17% when compared to the traditional hot process.
To study the potential for delayed Type IV dermal sensitivity of a new preservative system containing 1,2-hexanediol and caprylyl glycol, 200-subject repeat insult patch tests were performed with a 15% mixture of 1,2-hexanediol and caprylyl glycol (equal parts of the 2 ingredients) in carbomer gel and a cosmetic formulation at an actual use concentration. No delayed Type IV hypersensitivity reactions were observed.
Healthcare workers are required to disinfect the hands several times a day using hand disinfectants, which leads to chronic hand exposure to high levels of antimicrobials contained in the disinfectants, which could compromise the skin integrity. This problem may be addressed by developing hand disinfectants containing synergistic combinations of small amounts of antimicrobials and other agents. The synergistic effect of farnesol and essential oils with several antimicrobials was studied in vitro to select an effective antimicrobial system in preservative concentration for use in healthcare hand rub. Farnesol and lemon oil showed synergistic activity against S. aureus, in combination with benzalkonium chloride and benzethonium chloride, but not with other antimicrobials studied. All essential oils studied showed synergy with benzethonium chloride against Staphylococcus aureus and Escherichia coli. An alcohol-based healthcare hand rub (ZBF hand rub) containing this unique synergistic combination of farnesol and benzethonium chloride was then developed and its efficacy as a healthcare hand rub was evaluated in human volunteers according to the US FDA-TFM protocol using Serratia marcescens as a marker organism. The ZBF hand rub showed a 3.22 log(10) reduction in the microbial count after the first application and a 5.49 log(10) reduction after the tenth application in vivo and exceeds the US FDA-TFM criteria for healthcare hand rub. The ZBF hand rub did not irritate the hands when tested on human volunteers when applied 10 times everyday for five consecutive days. The ZBF hand rub exhibits more than 5.5 log(10) reduction in the microbial count within 15s and more than 2.8 log(10) reduction in the two types of viruses tested within 30s in vitro. When evaluated in an in vitro pig skin model, the ZBF hand rub shows better prolonged activity (20-35 min post-application) against transient bacteria (S. aureus and E. coli) compared to other alcohol-based hand rubs. These findings suggest that the use of the ZBF hand rub amongst health care workers may lower the risk of chronic hand exposure to high levels of antimicrobials without compromising the efficacy.
Preservativefree and self-preserving cosmetics and drugs: principles and practice
- J J Kabara
- D S Orth
Kabara JJ, Orth DS, editors. 1997. Preservativefree and self-preserving cosmetics and drugs:
principles and practice. New York: Mercel Dekker;