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Reactive Skin Decontamination Lotion (RSDL) -
Medical Countermeasures Database

1. Name of Chemical Defense therapeutic agent/device

Reactive Skin Decontamination Lotion (RSDL)

2. Chemical Defense therapeutic area(s)

    — including key possible uses

RSDL is used as a medical device for the decontamination of skin exposed to chemical warfare agents such as sulfur mustard, VX, VR and certain biological toxins.

3. Evidence-based medicine for Chemical Defense

    — including efficacy and safety

A. Summary

Mechanism of action

  • RSDL contains Dekon 139 and a small amount of 2,3-butanedione monoxime (DAM). These compounds are dissolved in a solvent composed of polyethylene glycol monomethyl ether (MPEG) and water. This solvent system is particularly important as it promotes the decontamination reaction by actively desorbing, retaining and sequestering the chemical agent, while the active ingredient (Dekon 139) chemically reacts with, and rapidly neutralizes the vesicant chemical or the organophophosphorous nerve agent. This reaction starts immediately and neutralization is usually complete within two minutes.

RSDL

Summary of clinical and non-clinical studies

The skin is the first line of defense against chemical warfare agents (CWAs) including nerve agents (VX, Russian VX [VR], and soman [GD]) and toxic industrial chemicals (TICs), providing a possible barrier or delay to systemic distribution. However, some chemicals act directly on the skin including the vesicants sulfur mustard (HD) and lewisite (L), and corrosive compounds such as strong acids or bases, and do not have to gain access to systemic circulation to cause extensive damage dermally (Schwartz et al., 2012). Thus, early and rapid skin decontamination is extremely important following exposure to CWAs and TICs because it decreases serious systemic or dermal damage not only to patients, but also the potential secondary toxic exposure to health care personnel. In 2003, the Food and Drug Administration (FDA) approved Reactive Skin Decontamination Lotion (RSDL) for decontamination of CWAs and T-2 fungal toxins. It actively partitions, sequesters, and retains agents and, through active oxime ingredients neutralizes any organophosphorus CWAs present. It has been demonstrated to be more efficacious than several other means of skin decontamination. In domestic swine treated with HD and VX, both RSDL/sponge system and Fuller's earth (FE) completely prevented cholinesterase (ChE) inhibition by VX poisoning, which indirectly indicates a prevention of toxic absorption through the skin (Taysse et al., 2007). RSDL/sponge system and FE also both had a beneficial effect on the intensity of skin lesions (erythemas) observed 3 days after VX exposure in comparison to sponge treatment alone, but only the RSDL/sponge system significantly prevented the formation of perinuclear vacuoles (p=0.003) and significantly decreased the infiltration of neutrophils into the dermis (p=0.003). RSDL and FE were also effective in increasing survival to 100% when administered 45 minutes after 5x LD50 VX exposure, although 50% of FE decontaminated animals exhibited serious signs of VX poisoning (Bjarnason et al., 2008). Following VR exposure, survival was also 100% when RSDL was administered 15 minutes after, but dropped to 50% when administered 30 minutes afer VR exposure (Mikler et al., 2011). Decontamination of VX-treated animals with 0.5% hypochlorite was less effective but also increased survival, whereas soapy water was ineffective in preventing lethality. In the hairless mouse screening model, both RSDL/sponge system and FE were able to reduce blisters 3 days after HD (2 μL) subcutaneous exposure, but only the RSDL/sponge system was able to reduce the necrosis of the epidermis and erosion (Taysse et al., 2011). RSDL was not, however, able to sufficiently prevent the inhibition of plasma ChE following VX (50 μg/kg) exposure at any ratio of decontaminant to toxicant used (sponge + RSDL 10, 20, and 50, whereas FE was able to significantly reduce the inhibition of ChE (p<0.001) in this model. When testing the effects following 5 times the median lethal dose (5x LD50) VR exposure in the domestic swine model, decontamination with RSDL was effective in protecting against the toxic effects of cutaneous exposure and preventing death when performed 15 minutes after VR exposure; however, when animals were decontaminated 30 minutes after exposure, the survival rate dropped to 50% (Mikler et al., 2011). Immobilizing the agent within the dermal reservoir by cooling of the VR or VX exposure sites for 2 or 6 hours prevented signs of OP poisoning and death during the cooling period, but these animals died ~1 hour following cessation of cooling unless they were decontaminated with RSDL or treated with oxime (HI-6 or pralidoxime) (Mikler et al., 2011; Sawyer et al., 2011). Analyses of blood VX levels showed that cooling exposure sites with ice packs acted to slow or prevent the entry of VX into the bloodstream from the skin (Sawyer et al., 2011). RSDL was also the most effective decontamination product tested in standard 2-minute GD decontamination experiments in the haired guinea pig model (Braue et al., 2011). The protective ratio (PR; the LD50 of the treatment group divided by the LD50 of the positive control animals) for the decontaminants RSDL, 0.5% bleach, 1% soapy water, and M291 skin decontamination kit (SDK) were 14, 2.7, 2.2, and 2.6, respectively. Since only RSDL provided good protection (PR>5), it was the only decontamination product evaluated for delayed-decontamination experiments. The delayed-decontamination time at which 50% of animals die in the test population following a 5x LD50 challenge (LT50) for RSDL was 4.0 minutes, meaning that RSDL must be administered within approximately 3 minutes in order to afford significant protection against GD. In a 2013 study, RSDL was tested at different times in hairless guinea pigs percutaneously challenged with 4x LD50 VX in IPA. The results showed that RSDL decontamination at 15 min after exposure could not prevent progressive blood cholinesterase inhibition and therefore would still require additional treatment. In the same 2013 study, a similar decontamination regimen with RSDL at 90 min showed that it still might effectively increase the time window of opportunity for treatment. Evidence of the efficacy of RSDL in animals models against a broad spectrum of CWAs and vesicants suggests it may have a role in mass human exposure chemical decontamination, that may be useful in both the military and civilian populations.

B. Link to clinical studies

Clinical reviews

  • Rapid decontamination of the skin is the single most important action to prevent dermal absorption of chemical contaminants in persons exposed to chemical warfare agents (CWA) and toxic industrial chemicals (TICs) as a result of accidental or intentional release. Chemicals on the skin may be removed by mechanical means through the use of dry sorbents or water. Recent interest in decontamination systems which both partition contaminants away from the skin and actively neutralize the chemical has led to the development of several reactive decontamination solutions. This article will review the recently FDA-approved Reactive Skin Decontamination Lotion (RSDL) and will summarize the toxicity and efficacy studies conducted to date. Evidence of RSDL's superior performance against vesicant and organophosphorus chemical warfare agents compared to water, bleach, and dry sorbents, suggests that RSDL may have a role in mass human exposure chemical decontamination in both the military and civilian arenas (Class IV).

Schwartz MD, Hurst CG, Kirk MA, Reedy SJ, Braue EH. Reactive Skin Decontamination Lotion (RSDL) for the Decontamination of Chemical Warfare Agent (CWA) Dermal Exposure. Curr Pharm Biotechnol. 2012 Aug 1;13(10):1971-9. [PubMed Citation]

C. Link to non-clinical (e.g. animal) studies

Adult animal studies

  • The organophosphate (OP) nerve agent VX is a weaponized chemical warfare agent that has also been used by terrorists against civilians. This contact poison produces characteristic signs of OP poisoning, including miosis, salivation, mastication, dysrhythmias and respiratory distress prior to death. Although successful treatment of OP poisoning can be obtained through decontamination and/or oxime reactivation of agent-inhibited cholinesterase, medical countermeasures that increase the therapeutic window for these measures would be of benefit. An anaesthetized swine model was utilized to examine the effects of lethal VX exposure to the skin, followed by cooling the exposure site prior to decontamination or treatment. The cooling was simply accomplished by using crushed ice in grip-seal plastic bags applied to the exposure sites. Cooling of skin exposed to lethal doses of VX significantly increased the window of opportunity for successful decontamination using the Reactive Skin Decontaminant Lotion® (RSDL®) or treatment with the oxime antidotes HI-6 and 2PAM. Analyses of blood VX levels showed that cooling acted to slow or prevent the entry of VX into the bloodstream from the skin. If the exposure site is known, the simple and non-invasive application of cooling provides a safe means with which to dramatically increase the therapeutic window in which decontamination and/or antidote treatment against VX are life-saving.

Sawyer TW, Mikler J, Worek F, Reiter G, Thiermann H, Tenn C, Weatherby K, Bohnert S. The therapeutic use of localized cooling in the treatment of VX poisoning. Toxicol Lett. 2011 Jul 4;204(1):52-6. [PubMed Citation]

  • Low volatile organophosphorous nerve agents such as VX, will most likely enter the body via the skin. The pharmacokinetics of drugs such as oximes, atropine and diazepam, are not aligned with the variable and persistent toxicokinetics of the agent. Repeated administration of these drugs showed to improve treatment efficacy compared to a single injection treatment. Because of the effectiveness of continuous treatment, it was investigated to what extent a subchronic pretreatment with carbamate (pyridostigmine or physostigmine combined with either procyclidine or scopolamine) would protect against percutaneous VX exposure. Inclusion of scopolamine in the pretreatment prevented seizures in all animals, but none of the pretreatments affected survival time or the onset time of cholinergic signs. These results indicate that percutaneous poisoning with VX requires additional conventional treatment in addition to the current pretreatment regimen. Decontamination of VX-exposed skin is one of the most important countermeasures to mitigate the effects of the exposure. To evaluate the window of opportunity for decontamination, the fielded skin decontaminant Reactive Skin Decontaminant Lotion (RSDL) was tested at different times in hairless guinea pigs percutaneously challenged with 4x LD50 VX in IPA. The results showed that RSDL decontamination at 15 min after exposure could not prevent progressive blood cholinesterase inhibition and therefore would still require additional treatment. A similar decontamination regimen with RSDL at 90 min showed that it still might effectively increase the time window of opportunity for treatment. In conclusion, the delay in absorption presents a window of opportunity for decontamination and treatment. The continuous release of VX from the skin presents a significant challenge for efficacious therapy, which should ideally consist of thorough decontamination and continuous treatment.

Joosen MJ, van der Schans MJ, Kuijpers WC, van Helden HP, Noort D. Timing of decontamination and treatment in case of percutaneous VX poisoning: a mini review. Chem Biol Interact. 2013 Mar 25;203(1):149-53. [PubMed Citation]

  • Research in skin decontamination and therapy of chemical warfare agents has been a difficult problem due to the simultaneous requirement of rapid action and nonaggressive behaviour. The aim of this study was to compare the performance of two decontaminating systems: the Canadian Reactive Skin Decontaminant Lotion (RSDL) and the Fuller's Earth (FE). The experiment was conducted with domestic swine, as a good model for extrapolation to human skin. RSDL and FE were tested against sulphur mustard (SM), a powerful vesicant, and VX, a potent and persistent cholinesterase inhibitor. When used 5 min after contamination, the results clearly showed that both systems were active against SM (10.1 mg/cm2) and VX (0.06 mg/cm2). The potency of the RSDL/sponge was statistically better than FE against skin injury induced by SM, observed 3 days post-exposure. RSDL was rather more efficient than FE in reducing the formation of perinuclear vacuoles and inflammation processes in the epidermis and dermis. Against a severe inhibition (67%) of plasmatic cholinesterases induced by VX poisoning, the potencies of the RSDL/sponge and FE were similar. Both systems completely prevented cholinesterase inhibition, which indirectly indicates a prevention of toxic absorption through the skin.

Taysse L, Daulon S, Delamanche S, Bellier B and Breton P. Skin decontamination of mustards and organophosphates: comparative efficiency of RSDL and Fuller's earth in domestic swine. Hum Exp Toxicol. 2007 Feb;26(2):135-41. [PubMed Citation]

  • The chemical weapon nerve agent known as Russian VX (VR) is a potent organophosphorus (OP) compound that is much less studied than its VX analogue with respect to toxicity, as well as to the effectiveness of several known countermeasures against it. An anaesthetized domestic swine model was utilized to assess several approaches in mitigating its toxicity, including the utility of cooling VR treated skin to increase the therapeutic window for treatment. The 6 h LD50 for VR topically applied on the ear was determined. Treatment of VR exposed animals (5x LD50) with pralidoxime (2PAM) very poorly regenerated inhibited blood cholinesterase activity, but was partially effective in preventing signs of OP poisoning and increasing survival. In contrast, treatment with the Hagedorn oxime HI-6 reactivated cholinesterase, eliminated all signs of poisoning and prevented death. Decontamination with the Reactive Skin Decontaminant Lotion (RSDL) 15 min after VR exposure was completely effective in preventing death. Cooling of the VR exposure sites for 2 or 6 h prevented signs of OP poisoning and death during the cooling period. However, these animals died very quickly after the cessation of cooling, unless they were treated with oxime or decontaminated with RSDL. Blood analyses showed that cooling of agent exposure sites delayed the entry of VR into the bloodstream. Medical treatment with HI-6 and to a lesser extent 2PAM, or decontamination with RSDL are effective in protecting against the toxic effects of cutaneous exposure to VR. Immobilizing this agent (and related compounds) within the dermal reservoir by cooling the exposure sites, dramatically increases the therapeutic window in which these medical countermeasures are effective.

Mikler J, Tenn C, Worek F, Reiter G, Thiermann H, Garrett M, Bohnert S, Sawyer TW. Immobilization of Russian VX skin depots by localized cooling: Implications for decontamination and medical countermeasures. Toxicol Lett. 2011 Sep 25;206(1):47-53. [PubMed Citation]

  • An anesthetized domestic swine model was used to compare the efficacy and cross-contamination potential of selected skin decontaminant products and regimens against the chemical warfare agent, VX. Animals topically exposed to 2x, 3x or 5x LD50 VX showed typical signs of organophosphate nerve agent poisoning, including miosis, salivation, mastication, dysrhythmias, and respiratory distress prior to death. Animals were exposed to 5x LD50 VX and then decontaminated 45 min later with the reactive skin decontamination lotion (RSDL®), Fuller's earth (FE), 0.5% hypochlorite, or soapy water. Survival was 100% when the reactive skin decontamination lotion or FE was utilized, although 50% of Fuller's earth decontaminated animals exhibited serious signs of VX poisoning. Decontamination of VX-treated animals with 0.5% hypochlorite was less effective but also increased survival. Soapy water was ineffective in preventing lethality. Blood cholinesterase levels were not predictive of clinical outcome in decontaminated animals. The potential of "decontaminated" VX in open wounds to cause poisoning was assessed by vigorously mixing 5x LD50 VX with the test decontaminants for 5 min and then placing the mixture onto a full-thickness skin wound. Soapy water was ineffective in preventing lethality. Although treatment with dry Fuller's earth prevented death and all signs of organophosphate poisoning, a significant proportion of treated animals decontaminated with Fuller's earth in aqueous suspension exhibited serious signs of organophosphate poisoning, suggesting that live agent may be desorbed from Fuller's earth when it is exposed to a liquid environment. Animals treated with reactive skin decontamination lotion or 0.5% hypochlorite-VX mixtures showed no signs of organophosphate poisoning during the 6- h test period.

Bjarnason S, Mikler J, Hill I, Tenn C, Garrett M, Caddy N and Sawyer TW. Comparison of selected skin decontaminant products and regimens against VX in domestic swine. Hum Exp Toxicol. 2008 Mar;27(3):253-61. [PubMed Citation]

  • Using the hairless mouse screening model presented in the companion paper the aim of this study was to assess two skin decontaminating systems: Fuller's earth (FE) and Reactive Skin Decontamination Lotion (RSDL)against two extremely toxic chemical warfare agents that represent a special percutaneous hazard, sulphur mustard (SM) and O-ethyl-S-(2[di-isopropylamino]ethyl)methyl-phosphonothioate (VX). Five minutes after being exposed on the back to either 2 mL of neat sulphur mustard or 50 mg/kg of diluted VX, mice were decontaminated. Both systems were able to reduce blisters 3 days after SM exposure. However, RSDL was found to be more efficient than FE in reducing the necrosis of the epidermis and erosion. In the case of VX exposure, RSDL, whatever the ratio of decontaminant to toxicant used (RSDL 10, 20, 50), was not able to sufficiently prevent the inhibition of plasma cholinesterases taken as a surrogate marker of exposure and toxicity. Only FE reduced significantly the ChE inhibition. Some of these observations are different from our previous results obtained in domestic swine and these changes are thus discussed in the perspective of using SKH-1 hairless mice for the initial in vivo screening of decontaminants.

Taysse L, Dorandeu F, Daulon S, Foquin A, Perrier N, Lallement G and Breton P. Cutaneous challenge with chemical warfare agents in the SKH-1 hairless mouse (II): Effects of some currently used skin decontaminants (RSDL and Fuller's earth) against liquid sulphur mustard and VX exposure. Hum Exp Toxicol. 2011 Jun;30(6):491-8. [PubMed Citation]

  • There have been numerous studies of the central nervous system (CNS) involvement in organophosphate (OP) poisoning showing status epilepticus and/or 'electrographic seizures'. Brain damage has been demonstrated as 'neuronal necrosis' primarily in the cortex, thalamus and hippocampus. To the authors' knowledge there have been no reports of partial/total paralysis following close upon OP exposure although delayed paralysis has been reported. This report summarizes the immediate, OP induced paralytic events recorded in guinea pigs during development of the Canadian reactive skin decontaminant lotion (RSDL®). As part of the development work, supra-lethal cutaneous doses of OP were applied to large numbers of guinea pigs followed by decontamination with the RSDL® or predecessor lotions and solvents. Soman (pinacolyl methylphosphonofluoridate; GD) challenges were applied to 1277 animals and S-(2-diisopropyl-aminoethyl) methylphosphorothiolate (VX) challenges to 108. The classic sequence of clinical signs - ptyalism, tremors, fasciculations, convulsions, apnea and flaccid paralysis before death - was seen in the 658 animals that died and in many of the survivors. Eighty-four of 688 survivors of GD and 4 of 39 survivors of VX showed random paralysis of various distal regions following recovery from an insult which produced convulsions and/or flaccid paralysis. Because the experiments were designed to assess the decontamination procedures, there were no apparent relationships between the amounts of OP applied and the sequellae recorded. The observations of paralysis were also incidental to the prime focus of the experiments. Because of this, only ten animals paralysed following GD exposure were examined for histological effects. The pathologist diagnosed 'encephalomalacia' and 'focal necrotic lesions' in the cerebral cortex and 'focal necrotic lesions' in one spinal cord. Of the 84 guinea pigs paralysed after GD challenge, one was not decontaminated and the decontaminants used on the remainder were sufficiently varied that there appeared to be no relationship between the type of decontaminant and the resulting paralysis.

Bide RW, Schofield L and Risk DJ. Immediate post-dosing paralysis following severe Soman and VX toxicosis in guinea pigs. J Appl Toxicol. 2005 Sep-Oct;25(5):410-7. [PubMed Citation]

  • Objective: This report, the second in a series of five, directly compares the efficacy of Reactive Skin Decontamination Lotion (RSDL), the M291 Skin Decontamination Kit (SDK), 0.5% bleach (sodium or calcium hypochlorite solution), 1% soapy water, and Skin Exposure Reduction Paste Against Chemical Warfare Agents (SERPACWA) in the haired guinea pig model following exposure to soman (GD). Methods: In all experiments, guinea pigs were close-clipped and given anesthesia. In the decontamination experiments, the animals were challenged with GD and decontaminated after a 2-minute delay for the standard procedure or at longer times for the delayed-decontamination experiments. Positive control animals were challenged with GD in the same manner as the treated animals, except that they received no treatment. All animals were observed during the first 4 hours and again at 24 hours after exposure for signs of toxicity and death. The protective ratio (PR, defined as the median lethal dose [LD50] of the treatment group divided by the LD50 of the untreated positive control animals) was calculated from the derived probit dose-response curves established for each treatment group and nontreated control animals. SERPACWA was applied as a thin coating (0.1 mm thick), allowed to dry for 15 minutes, and challenged with GD. After a 2-hour challenge, any remaining GD was blotted off the animal, but no additional decontamination was done. Significance in this report is defined as p <.05. Neat (undiluted) GD was used to challenge all animals in these studies. Results: In the standard 2-minute GD decontamination experiments, the calculated PRs for RSDL, 0.5% bleach, 1% soapy water, and M291 SDK were 14, 2.7, 2.2, and 2.6, respectively. RSDL was by far the most effective decontamination product tested and significantly better than any of the other products. Bleach, soapy water, and the M291 SDK provided equivalent and modest protection. Since only RSDL provided at least good protection (PR > 5), it was the only decontamination product evaluated for delayed decontamination. In the GD delayed decontamination experiments, the calculated LT50 (the delayed-decontamination time at which 50% of the animals die in the test population following a 5-LD50 challenge) value for RSDL was only 4.0 minutes. Conclusions: Several conclusions can be drawn from this study: 1) Reactive Skin Decontamination Lotion provided superior protection against GD compared with the other products tested; 2) The 0.5% bleach solution, the 1% soapy water solution, and the M291 SDK were less effective than RSDL, but still provided modest (2 < PR < 5) protection against GD; 3) Reactive Skin Decontamination Lotion, the best product tested, did not provide significant protection against GD when decontamination was delayed for more than 3 minutes; 4) Skin Exposure Reduction Paste Against Chemical Warfare Agents provided significant, but modest, protection against GD; 5) There was good correlation between using the rabbit model and the guinea pig model for decontamination efficacy evaluations; and 6) Soman (GD) is an agent of real concern because it is very difficult to decontaminate and the effects of exposure are difficult to treat.

Braue EH Jr, Smith KH, Doxzon BF, Lumpkin HL, Clarkson ED. Efficacy studies of Reactive Skin Decontamination Lotion, M291 Skin Decontamination Kit, 0.5% bleach, 1% soapy water, and Skin Exposure Reduction Paste Against Chemical Warfare Agents, Part 2: Guinea pigs challenged with soman. Cutan Ocul Toxicol. 2011 Mar;30(1):29-37. [PubMed Citation]

  • Reactive skin decontamination lotion (RSDL) is a proposed replacement for the existing skin and equipment decontamination kit. Because RSDL may need to be used to decontaminate wounded personnel, we conducted an assessment of the effect of this agent on wound healing. A skin incision model using male Sprague Dawley rats (n = 19 rats/group) was used. A 7.0-cm incision was made through the skin, and RSDL was (experimental group) or was not (control group) applied to the open wound; the wound edges were then approximated with sutures. Seven days later, animals were euthanized and wound samples were taken. Healing was assessed by measuring mechanical strength, collagen content, and histological appearance. RSDL-treated wounds had 23% lower tensile strength (p < 0.05) and 11% lower collagen content (p < 0.05) than did the untreated control wounds. Histological assessments did not differ significantly between groups. The results of this investigation demonstrate that the application of RSDL directly to an open wound impairs wound strength and decreases collagen content in the early phases of wound healing. This may have clinical implications for the treatment and outcomes of chemical casualty combat trauma.

Walters TJ, Kauvar DS, Reeder J, Baer DG. Effect of Reactive Skin Decontamination Lotion on Skin Wound Healing in Laboratory Rats. Mil Med. 2007 Mar;172(3):318-21. [PubMed Citation]

  • This report, first in a series of five, directly compares the efficacy of 4 decontamination products and Skin Exposure Reduction Paste Against Chemical Warfare Agents (SERPACWA) in the haired guinea pig model following exposure to VX. In all experiments, guinea pigs were close-clipped and given anesthesia. In the decontamination experiments, the animals were challenged with VX and decontaminated after a 2-minute delay for the standard procedure or at longer times for the delayed-decontamination experiments. Skin Exposure Reduction Paste Against Chemical Warfare Agents was applied as a thin coating (0.1 mm thick), allowed to dry for 15 minutes, and challenged with VX. After a 2-hour challenge, any remaining VX was blotted off the animal, but no additional decontamination was done. Positive control animals were challenged with VX in the same manner as the treated animals, except that they received no treatment. In addition, the positive control animals were always challenged with 5% VX in isopropyl alcohol (IPA) solution, whereas the treatment animals received either neat (undiluted) VX or 5% VX in IPA solution. All animals were observed during the first 4 hours and again at 24 hours after exposure for signs of toxicity and death. The protective ratio (PR, defined as the median lethal dose [LD(50)] of the treatment group divided by the LD(50) of the untreated positive control animals) was calculated from the probit dose-response curves established for each treatment group and nontreated control animals. Significance in this report was defined as p < .05. In the standard 2-minute neat VX decontamination experiments, the calculated PRs for Reactive Skin Decontamination Lotion (RSDL), 0.5% bleach, 1% soapy water, and the M291 Skin Decontamination Kit (SDK) were 66, 17, 16, and 1.1, respectively. Reactive Skin Decontamination Lotion was by far the most effective decontamination product tested and was significantly better than any of the other products. Bleach and soapy water provided equivalent and good (PR > 5) protection. They were both significantly better than the M291 SDK. The M291 SDK did not provide significant protection compared with positive controls. In the neat VX delayed-decontamination experiments, the calculated LT(50) (the delayed-decontamination time at which 50% of the animals died in the test population following a 5-LD(50) challenge) values for RSDL, 0.5% bleach, and 1% soapy water were 31, 48, and 26 minutes, respectively. The results showed that SERPACWA provided significant, but modest (PR < 5), protection against neat VX, with a PR of 2.1. Several conclusions can be drawn from this study: 1) RSDL provided superior protection against VX compared with the other products tested; 2) 0.5% bleach and 1% soapy water were less effective than RSDL, but still provided good protection against VX; 3) the M291 SDK was the least effective decontamination product and did not provide significant protection against VX; 4) the agent was observed to streak when using the M291 SDK, and efficacy may improve if the agent is first blotted, followed by wiping with a new or clean part of the M291 SDK pad; 5) RSDL, 0.5% bleach, and 1% soapy water provided significant protection against a 5-LD(50) challenge of VX, even when decontamination was delayed for up to about 30 minutes; and 6) SERPACWA provided significant, but modest, protection against VX.

Braue EH Jr, Smith KH, Doxzon BF, Lumpkin HL, Clarkson ED. Efficacy studies of Reactive Skin Decontamination Lotion, M291 Skin Decontamination Kit, 0.5% bleach, 1% soapy water, and Skin Exposure Reduction Paste Against Chemical Warfare Agents, part 1: guinea pigs challenged with VX. Cutan Ocul Toxicol. 2011 Mar;30(1):15-28. [PubMed Citation]

Pregnant animal studies

  • DAM has been shown to cross the placental barrier but teratogenicity studies have not been performed ; thus RSDL should only be used during pregnancy when absolutely necessary. RSDL has been shown to be non-mutagenic and inhalation and reproductive studies in rats have shown RSDL not to cause any ill effects

RSDL

Other non-clinical studies

Comparative human and animal in vitro studies
  • The chemical warfare agents such as VX represent a threat for both military and civilians, which involves an immediate need of effective decontamination systems. Since human scalp is usually unprotected compared to other body regions covered with clothes, it could be a preferential site of exposure in case of terrorist acts. The purpose of this study was to determine if skin decontamination could be efficient when performed more than 1h after exposure. In addition, the impact of hairs in skin contamination was investigated. By using in vitro skin models, we demonstrated that about 75% of the applied quantity of VX was recovered on the skin surface 2h after skin exposition, which means that it is worth decontaminating even if contamination occurred 2h before. The stratum corneum reservoir for VX was quickly established and persistent. In addition, the presence of hairs modified the percutaneous penetration of the nerve agent by binding of VX to hairs. Hair shaft has thus to be taken into account in the decontamination process. Reactive Skin Decontamination Lotion (RSDL) and Fuller's Earth (FE) were active in the skin decontamination 45min post-exposure, but RSDL was more efficient in reducing the amount of VX either in the skin or in the hair.

Rolland P, Bolzinger MA, Cruz C, Josse D, Briançon S. Hairy skin exposure to VX in vitro: effectiveness of delayed decontamination. Toxicol In Vitro. 2013 Feb;27(1):358-66. [PubMed Citation]

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4. Pharmacokinetic and toxicokinetics data

    — including children-, pregnancy-, geriatric-, and obesity-related data

Pregnancy

  • DAM has been shown to cross the placental barrier but teratogenicity studies have not been performed ; thus RSDL should only be used during pregnancy when absolutely necessary. RSDL has been shown to be non-mutagenic and inhalation and reproductive studies in rats have shown RSDL not to cause any ill effects

RSDL

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5. Current FDA/EUA approved indications and dosing

    — including children-, pregnancy-, geriatric-, and obesity-related data, and Emergency Use Authorization (EUA)

Adults (FDA)

  • Usage:
    The full strength solution is applied on body surfaces after exposure to chemical warfare agents (RSDL should not be used before exposure since its effectiveness following prophylactic use has not been evaluated). Generally, one 21 mL packet is sufficient to decontaminate hands, neck, and face. The packaging and sponge should be discarded after single use.

  • How Supplied:
    The FDA has cleared the use of RSDL in 21 and 42 mL packets. Each ml of solution contains 1.25 M or 173 mg of Dekon 139 and 35-43 mg of DAM in an MPEG and water solvent.

RSDL

Pregnancy (FDA)

  • DAM has been shown to cross the placental barrier but teratogenicity studies have not been performed ; thus RSDL should only be used during pregnancy when absolutely necessary. RSDL has been shown to be non-mutagenic and inhalation and reproductive studies in rats have shown RSDL not to cause any ill effects

RSDL

Emergency Use Authorization (FDA/CDC)

  • No Emergency Use Authorization for RSDL has been issued from the Food and Drug Administration under section 564 of the Federal Food, Drug and Cosmetic Act (FD&C Act) (21 U.S.C. 360bbb-3), amended by the Project Bioshield Act of 2004 (public Law 108-276).

[DHHS/FDA; Emergency Preparedness and Response-Counterterrorism and Emerging Threats (12/01/2011)]

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6. Current available formulations/shelf life

Formulation

  • Usage:
    The full strength solution is applied on body surfaces after exposure to chemical warfare agents (RSDL should not be used before exposure since its effectiveness following prophylactic use has not been evaluated). Generally, one 21 mL packet is sufficient to decontaminate hands, neck, and face. The packaging and sponge should be discarded after single use.

  • How Supplied:
    The FDA has cleared the use of RSDL in 21 and 42 mL packets. Each ml of solution contains 1.25 M or 173 mg of Dekon 139 and 35-43 mg of DAM in an MPEG and water solvent.

RSDL

Shelf life

Stability

  • The RSDL vehicle (MPEG) when combined with some commonly used decontamination materials, i.e., solid powdered HTH (calcium hypochlorite) or solid powdered Super Tropical Bleach causes spontaneous combustion. Should RSDL be used on the same decontamination line as either of these products, care must be taken to keep them apart.

  • Do not discard RSDL packaging and sponge into containers that contain or have contained HTH or Super Tropical Bleach.

E-Z-EM Canada Inc. Material Safety Data Sheet for Reactive Skin Decontamination Lotion, Date of Issue: 10/23/2006.

Storage

  • The RSDL vehicle (MPEG) when combined with some commonly used decontamination materials, i.e., solid powdered HTH (calcium hypochlorite) or solid powdered Super Tropical Bleach causes spontaneous combustion. Should RSDL be used on the same decontamination line as either of these products, care must be taken to keep them apart.

  • Do not discard RSDL packaging and sponge into containers that contain or have contained HTH or Super Tropical Bleach.

E-Z-EM Canada Inc. Material Safety Data Sheet for Reactive Skin Decontamination Lotion, Date of Issue: 10/23/2006.

 

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7. Current off label utilization and dosing

    — including children-, pregnancy-, geriatric-, and obesity-related data
  • No data available at this time.

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8. Route of Administration/Monitoring

  • Avoid extended contact with the skin. In emergency conditions, does not require immediate removal from the skin and can be left on under protective clothing, but should be rinsed as soon as it is safe to do so. One of the ingredients (DAM) is absorbed through the skin. RSDL has not been tested in humans using amounts required for decontamination. Intravenous injections of DAM have been shown to cause serious systemic toxicity up to and including a transient comatose state (unconsciousness). There have been no instances of death. Topical adverse effects are not expected to be nearly as severe as with intravenous administration. Pending further studies, do not use RSDL for whole body decontamination or use excessive quantities.

RSDL

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9. Adverse effects

  • One of the ingredients 2,3 butanedione monoxime (DAM) is absorbed through the skin. RSDL has not been tested in humans using amounts required for decontamination. Intravenous injections of DAM have been shown to cause serious systemic toxicity up to and including a transient comatose state (unconsciousness). There have been no instances of death. Topical adverse effects are not expected to be nearly as severe as with intravenous administration. Pending further studies, do not use RSDL for whole body decontamination or use excessive quantities.

RSDL

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10. Contraindication(s)

  • RSDL should not be used for wound decontamination because its effects on wounds and effects resulting from its absorption through the wound have not been studied.

RSDL

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11. Clinical studies in progress

    — including relevant ones and any others highlighting possible adverse effects and other effects/issues
  • No data available at this time.

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12. Non-clinical studies in progress

    — including relevant ones and any others highlighting possible adverse effects and other effects/issues
  • No data available at this time.

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13. Needed studies for Chemical Defense clinical indication

    — including pharmacokinetics, safety, efficacy, pregnancy, breastfeeding, and review panel recommendations
  • The Nerve Agents Subgroup recommended that (1) the requirements for use of RSDL to treat children in a mass casualty situation be determined and (2) RSDL be made available to treat children if it is safe and effective.

Biodefense Meeting. Best Pharmaceuticals for Children Act. Eunice Kennedy Shriver National Institute of Child Health and Human Development, September 8-9, 2008, Rockville, MD (NICHD)

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14. Needed studies for non Chemical Defense clinical indications

    — including review panel recommendations
  • The Nerve Agents Subgroup recommended that (1) the requirements for use of RSDL to treat children in a mass casualty situation be determined and (2) RSDL be made available to treat children if it is safe and effective.

Biodefense Meeting. Best Pharmaceuticals for Children Act. Eunice Kennedy Shriver National Institute of Child Health and Human Development, September 8-9, 2008, Rockville, MD (NICHD)

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15. Study-related ethical concerns

    — including review panel recommendations
  • No data available at this time.

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16. Global regulatory status

U.S.

The Food and Drug Administration (FDA) has cleared for use by the U.S. military a liquid decontamination lotion intended to remove or neutralize chemical warfare agents and T-2 fungal toxin from the skin. The lotion, called Reactive Skin Decontamination Lotion (RSDL), must be applied to exposed skin as soon as possible after exposure to a chemical agent.

FDA Drugs: FDA Clears Skin Lotion for Military to Protect Against Chemical Burns. March 28, 2003 (FDA)

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17. Other potentially useful information

  • Reactive Skin Decontamination Lotion (RSDL) is a patented, broad-spectrum liquid decontamination lotion intended to remove or neutralize chemical warfare agents or T-2 fungal toxin from the skin. It is FDA-approved for use by U.S. military and prehospital health care personnel. RSDL must be applied to exposed skin as soon as possible after exposure to a chemical agent. When exposed to chemical warfare agents, the user wipes the exposed skin with the lotion. The lotion removes the agents or the T-2 toxin and reacts with the chemical agents, rapidly neutralizing them so they are nontoxic. FDA cleared the lotion for use based on studies conducted by the U.S. Department of the Army that showed it is safe and effective. The Army tested the product's safety by conducting skin irritation, sensitization and photo irritation studies in more than 300 people. It tested its effectiveness by using it to treat animals that had been exposed to chemical agents.

Biodefense Meeting. Best Pharmaceuticals for Children Act. Eunice Kennedy Shriver National Institute of Child Health and Human Development, September 8-9, 2008, Rockville, MD (NICHD)

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18. Publications

Bide RW, Schofield L and Risk DJ. Immediate post-dosing paralysis following severe Soman and VX toxicosis in guinea pigs. J Appl Toxicol. 2005 Sep-Oct;25(5):410-7. [PubMed Citation]

Biodefense Meeting. Best Pharmaceuticals for Children Act. Eunice Kennedy Shriver National Institute of Child Health and Human Development, September 8-9, 2008, Rockville, MD (NICHD)

Bjarnason S, Mikler J, Hill I, Tenn C, Garrett M, Caddy N and Sawyer TW. Comparison of selected skin decontaminant products and regimens against VX in domestic swine. Hum Exp Toxicol. 2008 Mar;27(3):253-61. [PubMed Citation]

E-Z-EM Canada Inc. Material Safety Data Sheet for Reactive Skin Decontamination Lotion, Date of Issue: 10/23/2006.

Braue EH Jr, Smith KH, Doxzon BF, Lumpkin HL, Clarkson ED. Efficacy studies of Reactive Skin Decontamination Lotion, M291 Skin Decontamination Kit, 0.5% bleach, 1% soapy water, and Skin Exposure Reduction Paste Against Chemical Warfare Agents, part 1: guinea pigs challenged with VX. Cutan Ocul Toxicol. 2011 Mar;30(1):15-28 [PubMed Citation]

Braue EH Jr, Smith KH, Doxzon BF, Lumpkin HL, Clarkson ED. Efficacy studies of Reactive Skin Decontamination Lotion, M291 Skin Decontamination Kit, 0.5% bleach, 1% soapy water, and Skin Exposure Reduction Paste Against Chemical Warfare Agents, Part 2: Guinea pigs challenged with soman. Cutan Ocul Toxicol. 2011 Mar;30(1):29-37. [PubMed Citation]

[DHHS/FDA; Emergency Preparedness and Response-Counterterrorism and Emerging Threats (12/01/2011)]

E-Z-EM Canada Inc. Material Safety Data Sheet for Reactive Skin Decontamination Lotion, Date of Issue: 10/23/2006.

FDA Drugs: FDA Clears Skin Lotion for Military to Protect Against Chemical Burns. March 28, 2003 (FDA)

Joosen MJ, van der Schans MJ, Kuijpers WC, van Helden HP, Noort D. Timing of decontamination and treatment in case of percutaneous VX poisoning: a mini review. Chem Biol Interact. 2013 Mar 25;203(1):149-53. [PubMed Citation]

Mikler J, Tenn C, Worek F, Reiter G, Thiermann H, Garrett M, Bohnert S, Sawyer TW. Immobilization of Russian VX skin depots by localized cooling: Implications for decontamination and medical countermeasures. Toxicol Lett. 2011 Sep 25;206(1):47-53. [PubMed Citation]

Rolland P, Bolzinger MA, Cruz C, Josse D, Briançon S. Hairy skin exposure to VX in vitro: effectiveness of delayed decontamination. Toxicol In Vitro. 2013 Feb;27(1):358-66. [PubMed Citation]

Sawyer TW, Mikler J, Worek F, Reiter G, Thiermann H, Tenn C, Weatherby K, Bohnert S. The therapeutic use of localized cooling in the treatment of VX poisoning. Toxicol Lett. 2011 Jul 4;204(1):52-6. [PubMed Citation]

Schwartz MD, Hurst CG, Kirk MA, Reedy SJ, Braue EH. Reactive Skin Decontamination Lotion (RSDL) for the Decontamination of Chemical Warfare Agent (CWA) Dermal Exposure. Curr Pharm Biotechnol. 2012 Aug 1;13(10):1971-9. [PubMed Citation]

Taysse L, Daulon S, Delamanche S, Bellier B and Breton P. Skin decontamination of mustards and organophosphates: comparative efficiency of RSDL and Fuller's earth in domestic swine. Hum Exp Toxicol. 2007 Feb;26(2):135-41. [PubMed Citation]

Taysse L, Dorandeu F, Daulon S, Foquin A, Perrier N, Lallement G and Breton P. Cutaneous challenge with chemical warfare agents in the SKH-1 hairless mouse (II): Effects of some currently used skin decontaminants (RSDL and Fuller's earth) against liquid sulphur mustard and VX exposure. Hum Exp Toxicol. 2011 Jun;30(6):491-8. [PubMed Citation]

Walters TJ, Kauvar DS, Reeder J, Baer DG. Effect of Reactive Skin Decontamination Lotion on Skin Wound Healing in Laboratory Rats. Mil Med. 2007 Mar;172(3):318-21. [PubMed Citation]

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19. Web sites

RSDL

NIH CounterACT Program (HHS/NIH)



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Record last updated 9/3/2017