ClearSpray Information

Giarratana N et al. (2021). A sprayable Acid-Oxidizing solution containing hypochlorous acid (AOS2020) efficiently and safely inactivates SARS-Cov-2: a new potential solution for upper respiratory tract hygiene, 11: 1-5, Eur Arch Otorhinolaryngol.

Pure and stable hypochlorous acid is effective against the COVID-19 virus and is non-irritant to humans.

Introduction:

To eliminate the COVID-19 pandemic, the transmission of the virus SARS-CoV-2 among the population needs to be blocked and/or at least reduced. Upper respiratory tract viral loads are highest in the early stages of the disease, and high loads are associated with higher mortality rates. This study aims to evaluate the virucidal efficacy of AOS2020, a novel sprayable Acid-Oxidizing solution containing pure and stable hypochlorous acid (HClO), on human coronavirus SARS-Cov-2 in vitro, and the tolerability profile on nasal and oral mucosa suggesting to be a potential solution for upper respiratory hygiene.

Method:

Virucidal assays and intranasal and oral irritation tests were undertaken in accordance with relevant national and international guidance and methods.

Results:

In pre-clinical tests, the AOS2020, showed>99.8% virucidal efficacy in<1 data-preserve-html-node="true" min against SARS-Cov-2. The safety profile testing on both the nasal and oral mucosa indicates that AOS2020 is non-irritant.

Conclusion:

These initial results indicate that this product has the potential treatment to reduce viral load in the upper respiratory tract.

Miyaoka Y et al. (2021). Virucidal activity of slightly acidic hypochlorous acid water toward influenza virus and coronavirus with tests simulating practical usage, 297:198383, Virus Res.

Virucidal activity of slightly acidic hypochlorous acid water (SAHW) was evaluated. Avian influenza virus and avian coronavirus were used as test viruses. SAHW was evaluated in suspension and carrier (with non-porous and porous) tests. Sprayed SAHW inactivated viruses on rayon sheets to undetectable level.

Slightly acidic hypochlorous acid waters (SAHWs) with pH of 5.2-5.8 containing different concentrations of free available chlorine - 62, 119, 220, 300, and 540 ppm (SAHW-62, -119, -220, -300, and -540, respectively) - were evaluated for their virucidal activity toward a low pathogenic H7N1 avian influenza virus (AIV) and an infectious bronchitis virus (IBV) in suspension, abiotic carrier, and direct spray tests, with the presence of organic materials. In the carrier test, the dropping and wiping techniques were performed toward viruses on carriers. In the suspension test, SAHW-62 could decrease the viral titer of both AIV and IBV by more than 1000 times within 30 s. With the dropping technique, IBV on carriers showed high resistance to SAHW, while AIV on plastic carrier was inactivated to an effective level (≧3 log virus reduction) within 1 min. With the wiping technique, SAHW-62 could inactivate both AIV and IBV on wiped plastic carriers to an effective level within 30 s. However, SAHW-220 could not inactivate IBV in the wiping rayon sheet to an effective level. In the direct spray test, sprayed SAHW-300 within 10 min, and SAHW-540 within 20 min, inactivated AIV and IBV on the rayon sheets to undetectable level, respectively. Our study indicates that the usage of wipes with SAHW could remove viruses from plastic carriers, while viruses remained in the wipes. Besides, a small volume of sprayed SAHW was effective against the viruses on the rayon sheets for daily cleaning in the application area. The findings we obtained concerning IBV might basically be applicable in relation to SARS-CoV-2, given the resemblance between the two viruses.

Reynolds KA et al (2021). Impact of a Whole-Room Atomizing Disinfection System on Healthcare Surface Contamination, Pathogen Transfer, and Labor Efficiency, 3(2): e0340, Crit Care Explor.

Quantitative analysis shows that the addition of whole room HOCl atomized disinfection system formulated to release 850–1,000ppm of free chlorine at a pH of 6.0–6.5 to minimize corrosivity to existing terminal cleaning protocols lowered manual labor times, improved disinfection outcomes, and eliminated the transfer of bacterial tracers to previously uncontaminated surfaces within patient rooms.

Objectives:
Healthcare surfaces contribute to nosocomial disease transmission. Studies show that despite standard guidelines and practices for cleaning and disinfection, secondary infection spread among healthcare workers and patients is common in ICUs. Manual terminal cleaning practices in healthcare are subject to highly variable results due to differences in training, compliance, and other inherent complexities. Standard cleaning practices combined with no-touch disinfecting technologies, however, may significantly lower nosocomial infection rates. The objective of this study was to evaluate the efficacy of a whole-room, no-touch disinfection intervention to reduce the concentration and cross-contamination of surface bacteria when used in tandem with manual cleaning protocols.

Design:
ClO permeation measurements through protein membranes were performed and the time delay of ClO transport due to reaction and diffusion was determined. To calculate ClO₂ penetration depths and estimate bacterial killing times, approximate solutions of the reaction diffusion equation were derived. In these calculations evaporation rates of ClO₂ were also measured and taken into account.

Subjects and intervention:
Environmental service personnel cleaning efficacy was evaluated pre and post application of manual terminal cleaning protocols alone and in tandem with a whole-room atomization system with an United States Environmental Protection Agency-registered hospital-grade hypochlorous acid disinfectant.

Setting:
The study was conducted in an unoccupied patient room at Banner University Medical Center in Tucson, AZ. The room was located in a newly constructed ICU suite.

Measurements and main results:
Manual terminal cleaning averaged a 2.4 log10 reduction in seeded bacterial counts compared with a 4.9 average and up to a 6 log10 reduction with tandem cleaning. Cross-contamination among surfaces following terminal cleaning alone was documented in 50% of the samples compared with 0% with tandem cleaning, with the latter achieving a 64% improvement in manual labor efficiency.

Conclusion
The use of whole-room atomized disinfection with terminal cleaning protocols lowered manual labor times, improved disinfection outcomes, and eliminated the transfer of bacterial pathogens in healthcare environments.

Block MS, Rowan BG, (2020). Hypochlorous Acid: A Review, 78(9): 1461-1466. J Oral Maxillofac Surg.

A review of the literature indicates that HOCl is nontoxic and a practical disinfectant in its ability to sanitize against COVID-19 virus. It was shown in oral-maxillofacial clinic facility to work especially when used on a daily basis.

The surgeon needs to have an inexpensive, available, nontoxic, and practical disinfectant that is effective in sanitizing against the COVID-19 (Coronavirus Disease 2019) virus. The purpose of this article was to review the evidence for using hypochlorous acid in the office setting on a daily basis. The method used to assemble recommendations was a review of the literature including evidence for this solution when used in different locations and industries other than the oral-maxillofacial clinic facility. The results indicate that this material can be used with a high predictability for disinfecting against the COVID-19 (Coronavirus Disease 2019) virus.

Gold MH et al (2020). Topical stabilized hypochlorous acid: The future gold standard for wound care and scar management in dermatologic and plastic surgery procedures, 19(2): 270-277, J Cosmet Dermatol.

Stabilized Hypochlorous (HOCl) acid is an effective topical antiseptic agent. Applied as a topical treatment HOCl provides an optimal wound healing environment and when combined with a silicone gel may reduce scarring.

Background:
Hypochlorous acid (HOCl), a naturally occurring molecule produced by the immune system, is highly active against bacterial, viral, and fungal microorganisms. Moreover, HOCl is active against biofilm and increases oxygenation of the wound site to improve healing. Natural HOCl is unstable; through technology, it can be stabilized into an effective topical antiseptic agent.

Aim:
This paper focuses on the use of topical stabilized HOCl in wound and scar management for pre-, peri-, and postprocedures-including its ability to reduce the occurrence hypertrophic scars and keloids. The role of the product in other skin conditions is beyond the scope of this article.

Methods:
A panel comprising clinicians with experience in cosmetic and surgical procedures met late 2018 to discuss literature search results and their own current clinical experience regarding topical stabilized HOCl. The panel of key opinion leaders in dermatology and plastic surgery defined key insights and consensus statements on the direction of use for the product.

Results:
Topical stabilized HOCl provides an optimal wound healing environment and, when combined with silicone, may be ideal for reducing scarring. Additionally, in contrast to chlorhexidine, HOCl, used as an antiseptic skin preparation, raises no concerns of ocular- or ototoxicity.

Conclusions
For wound care and scar management, topical stabilized HOCl conveys powerful microbicidal and antibiofilm properties, in addition to potency as a topical wound healing agent. It may offer physicians an alternative to other less desirable wound care measures.

Herruzo R, Herruzo I (2020). Antimicrobial efficacy of a very stable hypochlorous acid formula compared with other antiseptics used in treating wounds: in-vitro study on micro-organisms with or without biofilm, 105(2): 289-294, J Hosp Infect.

Stable Hypochlorous acid compares very favorably with other antiseptics in treating wounds. It is effective against biofilms if applied at higher acceptable concentrations.

Background:

Many antiseptics have been used to treat wounds.

Aim:

To compare the microbicidal efficacy of ClHO (Clortech®) with other antiseptics used on wounds, healthy skin and mucous membranes.

Methods:
The microbicidal efficacy of 13 antiseptic products on eight micro-organisms (three Gram-positive; three Gram-negative; two yeasts) inoculated on organic germ-carriers was studied. In addition, the loss of efficacy against Staphylococcus aureus and Pseudomonas aeruginosa with biofilm was assessed with the six best-performing products.

Findings:

Chlorhexidine (1%) had the highest microbicidal effect at 1 min. At 5 min, 500 and 1500 mg/L ClHO showed similar, or better, activity than the other antiseptics studied. The ClHO concentration of 300 mg/L achieved this same efficacy at 10 min. The product that lost the most efficacy due to biofilm was 1% chlorhexidine, while 1% PVP-I and ClHO at either 300 or 500 mg/L were moderately affected by biofilm. The most effective in the presence of biofilm was ClHO at 1500 mg/L.

Conclusions:

ClHO at medium-low concentrations (300 or 500 mg/L) is a good antiseptic that can be used on wounds and mucous membranes for 5-10 min. Lower concentrations of ClHO, as well as of the other antiseptics studied, were less effective or more altered by the biofilm. ClHO at a concentration of 1500 mg/L is very effective in the presence or absence of biofilm that can be used on healthy skin for 5 min.

Lu M-C et al. (2020). Disinfection efficiency of hospital infectious disease wards with chlorine dioxide and hypochlorous acid, 5: 1-10, Aerobiologia (Bologna).

In a test of chlorine dioxide versus a weak solution of hypochlorous acid, chloride dioxide showed that it was a more effective disinfectant. However, disinfection efficiencies between the two were similar. One thing to note was the hypochlorous acid strength tested was at least half the normal strength typically used. The weaker level of strength was used in an attempt to match the two disinfectants due to fact that ClO2 can be destructive at higher levels while HOCl is not. EPA approved solution strength is 500 ppm and it can be used at higher levels.

The disinfection efficiencies of two chemical disinfectants, chlorine dioxide and weak acid hypochlorous water (WAHW), were examined in the soiled room and dishwashing room of a hospital infectious disease ward in Taiwan. The investigations were conducted in two seasons, namely winter and summer, in order to examine the correlation between the bioaerosol concentration and the environmental factors. In addition, a single-daily disinfection mode (SM) and a twice-daily disinfection mode (TM) were applied in this study. The results showed that the bacteria and fungi colony counts were strongly correlated with the temperature. Both disinfectants reduced the bacteria and fungi concentrations in the considered rooms. However, of the two disinfectants, the ClO2 showed a stronger disinfection effect than the WAHW. It means that when using ClO2 as the disinfectant, the disinfection efficiency of the TM treatment mode is significantly better than that of the SM treatment mode. But, when using WAHW as the disinfectant, no significant difference is found between the disinfection efficiencies of the two methods. Overall, the results showed that the application of ClO2 twice daily provided the most effective means of satisfying the Taiwan EPA guidelines for the indoor air quality of hospital medical wards.

McMahon NZ et al. (2020) Efficacy of Wound Cleansers on Wound-Specific Organisms Using In Vitro and Ex Vivo Biofilm Models, 66(11):31-42, Wound Manag Prev.

Hypochlorous acid (HOCl) along with the other commercial cleansers were tested against several biofilm generating organisms in models of injury. HOCl was successful against immature organisms but weak solutions were not successful after only 10 minutes of application. The HOCl solutions tested were about 33 ppm and 330 ppm. The EPA suggests that 500 ppm is the minimum strength that should be used to disinfect biofilm forming bacteria and higher levels can be applied without out harm.

It should be noted, most effective antiseptic, polyhexamethylene biguanide (PHMB), has been classified as carcinogenic category 2 by the European Chemical Agency (ECHA). Products containing concentrations of 1% PHMB and more must be declared as “suspected of causing cancer” and concentrations of 0.1% or above have to be noted in safety datasheets. PHMB is allowed as a part of cosmetic products (max. 0.1%) if exposure by inhalation is impossible. On April 20, 2018, the ECHA decided to ban preservative uses of PHMB PT9. It is still allowed for uses as disinfectants PT2 (Disinfectants and algaecides not intended for direct application to humans or animals).

Biofilms are believed to be a source of chronic inflammation in non-healing wounds. PURPOSE: In this study, the pre-clinical anti-biofilm efficacy of several wound cleansers was examined using the Calgary minimum biofilm eradication concentration (MBEC) and ex vivo porcine dermal explant (PDE) models on Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans biofilms. METHODS: A surfactant-based cleanser and antimicrobial-based cleansers containing ionic silver, hypochlorous acid (HOCl), sodium hypochlorite (NaOCl), and polyhexamethylene biguanide (PHMB) were tested on the MBEC model biofilms with a 10-minute application time. Select cleansers were then tested on the mature PDE biofilms with 10-minute applications followed by the application of cleanser-soaked gauze. The PDE model was further expanded to include single and daily applications of the cleansers to mimic daily and 72-hour dressing changes. RESULTS: In the MBEC model, PHMB- and HOCl-based cleansers reduced immature MRSA, C albicans, and P aeruginosa biofilm regrowth by > 3× when compared with silver, surfactant, and saline cleansers. The major differences could be elucidated in the PDE model in which, after daily application, 1 PHMB-based cleanser showed a statistically significant reduction (3–8 CFU/mL log reduction) in all mature biofilms tested, while a NaOCl-based cleanser showed significant reduction in 2 microorganisms (3–5 CFU/mL log reduction, P aeruginosa and MRSA). The other PHMB-based cleanser showed a statistically significant 3 log CFU/mL reduction in P aeruginosa. The remaining cleansers showed no statistically significant difference from the saline control. CONCLUSION: Results confirm that there are model-dependent differences in the outcomes of these studies, suggesting the importance of model selection for product screening. The results indicate that 1 PHMB-based cleanser was effective in reducing mature P aeruginosa, MRSA, and C albicans biofilms and that sustained antimicrobial presence was necessary to reduce or eliminate these mature biofilms.

Scarano A et al (Oct 2020). Environmental Disinfection of a Dental Clinic during the Covid-19 Pandemic: A Narrative Insight, 2020: 1-15. Biomed Res Int.

This review was conducted to evaluate the scientific literature on the no-touch disinfection procedures in dental clinics aiming to limit disease transmission via airborne particles or fomites. Using a no-touch procedures for environmental decontamination technique that best suits the needs of the dental clinic hypochlorous solution was shown to be effective against COVID-19.

Background:

The control of biological hazard risk in health care and dental clinic environments represents a critical point in relation to the Covid-19 infection outbreak and international public health emergency. The purpose of the present review was to evaluate the scientific literature on the no-touch disinfection procedures in dental clinics aiming to limit transmission via airborne particles or fomites using no-touch procedures for environmental decontamination of dental clinics.

Methods:

An electronic database literature search was performed to retrieve research papers about Covid-19 and no-touch disinfection topics including full-length articles, editorials, commentaries, and outbreak studies. A total of 86 papers were retrieved by the electronic research.

Results:

No clinical article about the decontamination of a dental clinic during the Covid-19 pandemic was detected. About the topic of hospital decontamination, we found different no-touch disinfection procedures used in hospital against highly resistant organisms, but no data were found in the search for such procedures with respect to SARS-CoV-2: (1) aerosolized hydrogen peroxide, (2) H2O2 vapor, (3) ultraviolet C light, (4) pulsed xenon, and (5) gaseous ozone. One paper was retrieved concerning SARS-CoV-2; 32 documents focused on SARS and MERS. The cleaning and disinfection protocol of health care and dental clinic environment surfaces are essential elements of infection prevention programs, especially during the SARS-CoV-2 pandemic.

Conclusion:

The decontamination technique that best suits the needs of the dental clinic is peroxide and hypochlorous which can be sprayed via a device at high turbine speed with the ability of producing small aerosol particles, recommendable also for their low cost.

Tran AQ, et al. (2020). Comparison of Skin Antiseptic Agents and the Role of 0.01% Hypochlorous Acid, SJAA322. Aesthet Surg J.

A weak 0.01% (100 ppm) hypochlorous (HA) solution was tested for antiseptic properties against other agents and was found to reduce bacterial growth even at this very low concentration and was still effective after only 1 minute of application. Other antiseptic agents such as CHG were more effective. However, HA is usually applied at 500 ppm and for longer time to achieve its full effects. The study does show that even a weak solution and a short application time has a positive effect.

Background:

Hypochlorous acid has both anti-microbial and wound healing properties with a growing role for use in pre-procedural care on the face.

Objectives:

To compare the antiseptic property of 0.01% hypochlorous solution (HA), 5% povidone iodine (PI), 4% chlorhexidine (CHG) and 70% isopropyl alcohol (IPA) antiseptic on facial skin.

Methods:

A prospective single-center clinical trial.

Results:

A total of 21 participants were recruited. Bacterial growth was seen in CHG (10%), IPA (71%), PI (81%) and HA (95%) of specimens (p < 0.001). CHG had less growth when compared to HA (p = <0.001), data-preserve-html-node="true" IPA (p = <0.001) data-preserve-html-node="true" and PI (p = <0.001). data-preserve-html-node="true" No difference in bacterial growth was seen between HA and IPA (p = 0.063) or HA and PI (p = 0.25). Significant differences in mono-microbial and poly-microbial growth was seen between HA and IPA (p = 0.046) and HA and CHG (p= < 0.001). Staphylococcus epidermidis grew less frequently in CHG (10%), followed by IPA (29%), PI (71%) and HA (71%). Staphylococcus capitis grew less frequently in CHG (0%), followed by PI (14%), HA (24%) and IPA (29%).

Conclusions:

CHG reduced the bacterial growth compared to HA, PI, and IPA. However, HA, PI and IPA had insignificant differences in bactericidal effects. Our study provides a supporting role of HA to be considered as an antiseptic.

Wongkietkachorn A et al. (2020). The Use of Hypochlorous Acid Lavage to Treat Infected Cavity Wounds, 8(1): e2604. Plast Reconstr Surg Glob Open.

Hypochlorous acid used to irrigate a wound lead to a subsiding of a fever and the reduction of infecting microorganisms. Other treatments were not successful.

Managing cavity wounds that cannot be cleaned using standard irrigating solution is challenging. An immunocompromised patient with a horseshoe perianal abscess was selected to represent a heavy infection in cavity wounds. Diluted povidone-iodine was initially used to lavage the wounds, but the fever persisted and the irrigation was painful. Hypochlorous acid was then used to irrigate the wound. One day after administration of the hypochlorous acid, the fever began to subside, suggesting that this solution was able to adequately destroy the infecting microorganisms. The patient rated his pain during this procedure as 2/10. The infection had cleared within 2 weeks, and a swab culture found no microbial growth. The wound volume was reduced by more than 90% after 5 weeks, and final wound closure was achieved after 6 weeks. By comparison, another patient with a horseshoe perianal abscess who underwent traditional irrigation with diluted povidone-iodine and wet-to-dry dressing faced similar problems, but the fever in this case did not subside, and the wound became more complicated. He complained of pain during the irrigation with diluted povidone-iodine, giving the procedure a pain score of 10/10. Wound care was also difficult due to fecal contamination. As a result, the patient had to undergo colostomy to divert feces to the abdomen, thus preventing it from contaminating the wound. Time to final wound closure was 10 weeks. These cases illustrate the effectiveness of hypochlorous acid in dealing with infection in wound cavities.

Anagnostopoulos AG et al. (2018). 0.01% Hypochlorous Acid as an Alternative Skin Antiseptic: An In Vitro Comparison, 44(12):1489-1493. Dermatol Surg.

Hypochlorous acid even at a weak 100 ppm had immediate bactericidal effects against all bacteria tested. At the EPA minimum of 500 ppm one can expect even better positive effects.

Objective:

Compare the in vitro efficacy of hypochlorous acid 0.01% (HA), povidone iodine 5% (PI), chlorhexidine gluconate 4% (CHG), and isopropyl alcohol 70% (IPA) against common skin microorganisms.

Materials and methods:

Time-kill studies were conducted against methicillin-susceptible Staphylococcus aureus (MSSA) and Staphylococcus epidermidis (MSSE), methicillin-resistant S. aureus (MRSA) and S. epidermidis (MRSE), Candida albicans, Corynebacterium species (striatum and amycolatum), Propionibacterium acnes, Pseudomonas aeruginosa, Streptococcus pyogenes, Staphylococcus capitis, and Staphylococcus xylosus.

Results:

Methicillin-resistant S. aureus: Bactericidal effect was immediate for HA and IPA. For PI and CHG, the effect occurred at 1 and 10 minutes, respectively. Methicillin-resistant S. epidermidis: Hypochlorous acid, IPA, and PI had immediate bactericidal effects, whereas CHG required 1 minute. Methicillin-susceptible Staphylococcus aureus: All agents had bactericidal effects at 1 minute. C. species, S. pyogenes, P. aeruginosa, and P. acnes: All antiseptics demonstrated immediate bactericidal effects. Methicillin-susceptible Staphylococcus epidermidis and S. capitis: Hypochlorous acid and IPA had immediate effect, whereas PI and CHG required 1 minute. C. albicans: Hypochlorous acid, IPA, and PI were immediately bactericidal, whereas CHG required 1 minute. S. xylosus: Hypochlorous acid and CHG were immediately bactericidal, whereas IPA and PI required 1 and 2 minutes, respectively.

Conclusion:
In vitro studies of HA 0.01% were observed to have equal or more efficacious antiseptic properties compared with IPA, CHG, and PI. Future studies will be needed to investigate its role in periocular use.

Gold MH et al. (2017). Hypochlorous acid gel technology-Its impact on postprocedure treatment and scar prevention, 16(2):162-167. J Cosmet Dermatol.

The use of hypochlorous acid to prevent infection, reduction of inflammation and scarring risk when combined with silicon oil showed optimal outcomes which includes reducing the risk of scarring.

Background:

A pre-and postprocedure regime aimed at prevention of infection, reduction of inflammation and risk of scarring, is to enable optimal outcomes.

Objectives:

The role of a hypochlorous acid containing spray and translucent scar gel formulation that combines modified silicon oil with hypochlorous acid, was explored for pre- and postprocedure treatment and scar management. Methods: For this purpose a literature review was conducted to explore the value of the technology used in pre-and postprocedural regimes. A panel of dermatologists and plastic surgeons who practice in the United States discussed the summarized search results, taking into account their current clinical practice. A nominal group process for consensus was used, followed by online reviews of the manuscript.

Results:

Based on panel discussions, consensus was reached regarding clinical recommendations given for postprocedure treatment and scar management. The hypochlorous acid products are produced with electrolysis and are classified among biocidal substances. The technology has demonstrated efficacy and safety for pre-and postprocedure use. The safety of hypochlorous solution use demonstrated to be comparable to that of standard local antiseptics. Small studies demonstrated better results with the scar gel compared to silicone gel regarding the appearance of hypertrophic and keloid scars, relief of associated pruritus and pain.

Conclusions:

A postprocedure regime using this technology, aimed at preventing infection, reducing inflammation, and promoting healing is proposed to have benefits over current regimes as it appears to be effective, safe, and well tolerated.

Ishihara M et al. (2017). Stability of Weakly Acidic Hypochlorous Acid Solution with Microbicidal Activity, 22(4):223-227. Biocontrol Sci.

Hypochlorous acid solution, when produced from pure water with very low concentrations of various compounds and ions was stable especially when stored in dark, cool conditions.

Hypochlorous acid (HOCl) solution (200 ppm, pH 6) was prepared and evaluated for their stabilities and microbicidal activities. We demonstrated that HOCl is unstable against ultraviolet (UV) light, sunshine, contact with air, and elevated temperature (≧25℃). Furthermore, in the HOCl solution, the presence of excess NH2- or CHO-containing organic compounds such as proteins and carbohydrates, or of inorganic ions such as NO2-, SO3-, PO3-, Fe2+, Cu2+, and CuS, resulted in the rapid consumption of HOCl by oxidation reactions, and significantly decreased the microbicidal activity of the HOCl solution against coliform bacteria and total viable cell count. Thus, production of stable HOCl solution requires formulation in pure water harboring concentrations as low as possible of various compounds and ions, as well as storage in dark and cool conditions (<10℃) data-preserve-html-node="true" to maintain the concentration of HOCl molecules and microbicidal activity.

Sakarya S et al. (2014). Hypochlorous Acid: An Ideal Wound Care Agent With Powerful Microbicidal, Antibiofilm, and Wound Healing Potency, 26(12):342-350. WOUNDS.

Stable hypochlorous acid solution was shown to be an ideal wound care solution with a powerful and rapid killing effect on different types of microorganisms, antibiofilms, and microbicidal effect within the biofilm. Foremost, it has dose-dependent favorable effects on fibroblast and keratinocyte migration. These features suggests stabilized HOCl solution is an ideal wound care agent.

Introduction. Chronic wounds and the infections associated with them are responsible for a considerable escalation in morbidity and the cost of health care. Infection and cellular activation and the relation between cells are 2 critical factors in wound healing. Since chronic wounds offer ideal conditions for infection and biofilm production, good wound care strategies are critical for wound healing. Topical antiseptics in chronic wounds remain in widespread use today. These antiseptics are successful in microbial eradication, but their cytotoxcity is a controversial issue in wound healing. Objective. The aim of this study was to investigate the effect of stabilized hypochlorous acid solution (HOCl) on killing rate, biofilm formation, antimicrobial activity within biofilm against frequently isolated microorganisms and migration rate of wounded fibroblasts and keratinocytes. Materials and Methods. Minimal bactericidal concentration of stabilized HOCl solution for all standard microorganisms was 1/64 dilution and for clinical isolates it ranged from 1/32 to 1/64 dilutions. Results. All microorganisms were killed within 0 minutes and accurate killing time was 12 seconds. The effective dose for biofilm impairment for standard microorganisms and clinical isolates ranged from 1/32 to 1/16. Microbicidal effects within the biofilm and antibiofilm concentration was the same for each microorganism. Conclusion. The stabilized HOCl solution had dose-dependent favorable effects on fibroblast and keratinocyte migration compared to povidone iodine and media alone. These features lead to a stabilized HOCl solution as an ideal wound care agent.

Ono T et al. (2012). Microbicidal effect of weak acid hypochlorous solution on various microorganisms, 17(3):129-33. Biocontrol Sci.

Most of the bacterial strains used in this study were those involved in nosocomial infections and some of them had acquired drug resistance. The use of even a weak hypochlorous solution was practical because it showed microbicidal effects at low concentrations and short contact time. This would allow the reduction of antibiotics, environmental improvements for control of nosocomial hospital infections.

We investigated the microbicidal effect of weak acid hypochlorous solutions of pH 5.0 - 6.0, produced by mixing NaClO and HCl in water, against various bacteria, fungi, and virus in vitro. The weak acid hypochlorous solution had excellent microbicidal effect against a broad microbicidal spectrum of standard strains and clinical isolates in a short time. The microbicidal effects of hypochlorous solutions did not depend on the available chlorine concentration but on the HClO concentration. These results show that the weak acid hypochlorous solution has practical applicability in such places as hospitals and establishments related to the food industry.

Dukan S et al. (15 July 1999). Reactive Oxygen Species Are Partially Involved in the Bacteriocidal Action of Hypochlorous Acid, 367:311-316. Arch Biochem Biophys.

Hypochlorous acid, a widely used disinfectant has an important role in inflammation and human resistance to infection. Bacteria challenged aerobically with different HOCl concentrations exhibit higher ability to form colonies anaerobically than aerobically. Conversely, aerobic plating greatly increased lethality after an anaerobic HOCl challenge. Even a short transient exposure to air after anaerobic HOCl challenge reduced anaerobic survival, indicative of immediate deleterious effects of oxygen. Exposure to HOCl can cause lethal DNA damage to the bacteria.

Hypochlorous acid (HOCl) is probably the most widely used disinfectant worldwide and has an important role in inflammatory reaction and in human resistance to infection. However, the nature and mechanisms of its bactericidal activity are still poorly understood. Bacteria challenged aerobically with HOCl concentrations ranging from 9.5 to 76 microM exhibit higher ability to form colonies anaerobically than aerobically. Conversely, aerobic plating greatly increased lethality after an anaerobic HOCl challenge, although anaerobic survival did not depend on whether HOCl exposure was aerobic or anaerobic. Even a short transient exposure to air after anaerobic HOCl challenge reduced anaerobic survival, indicative of immediate deleterious effects of oxygen. Exposure to HOCl can cause lethal DNA damage as judged by the fact that recA sensitivity to HOCl was oxygen dependent. Antioxidant defenses such as reduced glutathione and glucose-6-phosphate dehydrogenase were depleted or inactivated at 10 microM HOCl, while other activities, such as superoxide dismutase, dropped only above 57 microM HOCl. Cumulative deficiencies in superoxide dismutase and glucose-6-phosphate dehydrogenase rendered strains hypersensitive to HOCl. This indicates that part of HOCl toxicity on Escherichia coli is mediated by reactive oxygen species during recovery.

Vissers MCM et al. (1999). Hypochlorous acid causes caspase activation and apoptosis or growth arrest in human endothelial cells, 344: 443-449. Biochem. J. (1999).

This study was performed on endothelial cells in culture. The generation of a potent oxidant like hypochlorous is not without risk to the host, and there is evidence that HOCl contributes to the tissue injury associated with inflammation. The biological reactivity of HOCl and detail knowledge about how it interacts with mammalian cells is still under investigation, but it is known that the outcome is exposure dependent. Endothelial cells are intimately involved in the recruitment of leucocytes and is exposed to stimulated neutrophils in many inflammatory conditions. The ability of HOCl to induce growth arrest or apoptosis in these cells would be advantageous in allowing the repair or removal of damaged cells in a way that did not exacerbate inflammation. The proposal that HOCl can initiate controlled responses also suggests that neutrophils could use their machinery for cell signaling.

We have investigated the effect of hypochlorous acid (HOCl) on cultured human umbilical-vein endothelial cells and shown that, whereas higher concentrations cause rapid necrosis, smaller amounts of this oxidant induce apoptosis or growth arrest. Exposure to 20-40 nmol of HOCl per 1.2x10(5) cells initiated apoptosis that was determined morphologically, by the identification of apoptotic nuclei with Hoechst 33342, and by detection of phosphatidylserine on the outer membrane. Degraded DNA was detected by flow cytometry. HOCl induced caspase activity; specific inhibition of caspases was shown to prevent apoptosis. No caspase activation could be detected with 50 nmol of HOCl per 1.2x10(5) cells, a dose that caused more extensive necrosis. Lower doses of HOCl, which did not cause cell death, resulted in a transient growth arrest that was apparent with as little as 5 nmol of HOCl per 1.2x10(5) cells. These results show that HOCl can modify cellular responses that are dependent on signal transduction pathways in a manner similar to that of other oxidants.