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Hermann Feldmeier - One of the best experts on this subject based on the ideXlab platform.
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efficacy and safety of Dimeticones in the treatment of epidermal parasitic skin diseases with special emphasis on tungiasis an evidence based critical review
Brazilian Journal of Infectious Diseases, 2020Co-Authors: Hollman Miller, Julian Trujillotrujillo, Francis Mutebi, Hermann FeldmeierAbstract:Abstract Epidermal parasitic skin diseases encompass scabies, pediculosis, cutaneous larva migrans, myiasis, and tungiasis. Tungiasis is probably the most neglected of all Neglected Tropical Diseases (NTD). It occurs in South America, the Caribbean and Sub-Saharan Africa and affects marginalized populations where people live in extreme poverty. In endemic communities the prevalence can be up to 30% in general population and 85% in children. Over time, chronic pathology develops characterized by hyperkeratosis, edema around the nail rim, fissures, ulcers, deformation and loss of nails. This leads to a pattern of disabilities, eventually resulting in impairment of mobility. Dimeticones are a family of silicon oils with a potential to kill parasites located on top or inside the epidermis by a physical mode of action. They are considered the treatment of choice for pediculosis capitis and pediculosis pubis. With regard to tungiasis, the so called rear abdominal cone of the parasites has been identified as a target for treatment with Dimeticones. NYDA®, a mixture of two Dimeticones with different viscosity, is the only Dimeticone product for which data on the mode of action, efficacy and safety with regard to tungiasis exists. The product has been shown highly effective against embedded sand fleas, even in very intense infection with more than 500 parasites situated on top of each other. A randomized controlled trial showed that seven days after a targeted application of NYDA® 97% (95% CI 94–99%) of the embedded sand fleas had lost all signs of viability. Comprehensive toxicological investigations on the Dimeticones contained in NYDA® showed that there is practically no risk of embryotoxicity, fetotoxicity, teratogenicity, and other toxicity. The safety of Dimeticones was also demonstrated in clinical trials with a total of 106 participants with tungiasis, in which not a single adverse event was observed.
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Treatment of tungiasis with a two-component Dimeticone: a comparison between moistening the whole foot and directly targeting the embedded sand fleas
Tropical Medicine and Health, 2017Co-Authors: Per Nordin, Marlene Thielecke, Nicholas Ngomi, George Mukone Mudanga, Ingela Krantz, Hermann FeldmeierAbstract:Background Tungiasis (sand flea disease) is caused by the penetration of female sand fleas ( Tunga penetrans , Siphonaptera) into the skin. It belongs to the neglected tropical diseases and is prevalent in South America, the Caribbean and sub-Saharan Africa. Tungiasis predominantly affects marginalized populations and resource-poor communities in both urban and rural areas. In the endemic areas, patients do not have access to an effective and safe treatment. A proof-of-principle study in rural Kenya has shown that the application of a two-component Dimeticone (NYDA®) which is a mixture of two low viscosity silicone oils caused almost 80% of the embedded sand fleas to lose their viability within 7 days. Methods In this study we compared the efficacy of two distinct modes of application of NYDA®; one targeted application to the area where the parasite protrudes through the skin and one comprehensive application to the whole foot. Results Independent of the two modes of application, the Dimeticone caused more than 95% of embedded sand fleas to lose all signs of viability within 7 days. The targeted application killed embedded sand fleas more rapidly compared to when the whole foot was covered. The proportion of viable lesions at day two were 7.0 versus 23.4% ( p < 0.01) and at day five 3.9 versus 12.5% ( p < 0.02). Conclusions Our findings suggest that the Dimeticone could provide a safe and effective treatment for tungiasis in areas with difficult access to health care. Trial registration ISRCTN ISRCTN74306878
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treatment of tungiasis with a two component Dimeticone a comparison between moistening the whole foot and directly targeting the embedded sand fleas
Tropical Medicine and Health, 2017Co-Authors: Per Nordin, Marlene Thielecke, Nicholas Ngomi, George Mukone Mudanga, Ingela Krantz, Hermann FeldmeierAbstract:Tungiasis (sand flea disease) is caused by the penetration of female sand fleas (Tunga penetrans, Siphonaptera) into the skin. It belongs to the neglected tropical diseases and is prevalent in South America, the Caribbean and sub-Saharan Africa. Tungiasis predominantly affects marginalized populations and resource-poor communities in both urban and rural areas. In the endemic areas, patients do not have access to an effective and safe treatment. A proof-of-principle study in rural Kenya has shown that the application of a two-component Dimeticone (NYDA®) which is a mixture of two low viscosity silicone oils caused almost 80% of the embedded sand fleas to lose their viability within 7 days. In this study we compared the efficacy of two distinct modes of application of NYDA®; one targeted application to the area where the parasite protrudes through the skin and one comprehensive application to the whole foot. Independent of the two modes of application, the Dimeticone caused more than 95% of embedded sand fleas to lose all signs of viability within 7 days. The targeted application killed embedded sand fleas more rapidly compared to when the whole foot was covered. The proportion of viable lesions at day two were 7.0 versus 23.4% (p < 0.01) and at day five 3.9 versus 12.5% (p < 0.02). Our findings suggest that the Dimeticone could provide a safe and effective treatment for tungiasis in areas with difficult access to health care. ISRCTN ISRCTN74306878
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Treatment of Tungiasis with Dimeticone: A Proof-of- Principle Study in Rural Kenya
2016Co-Authors: Marlene Thielecke, Per Nordin, Nicholas Ngomi, Hermann FeldmeierAbstract:Tungiasis (sand flea disease) is a neglected tropical disease, prevalent in resource-poor communities in South America and sub-Saharan Africa. It is caused by an inflammatory response against penetrated female sand fleas (Tunga penetrans) embedded in the skin of the host. Although associated with debilitating acute and chronic morbidity, there is no proven effective drug treatment. By consequence patients attempt to remove embedded sand fleas with non-sterile sharp instruments, such as safety pins, a procedure that represents a health threat by itself. In this proof-of-principle study we compared the topical application of a mixture of two Dimeticones of low viscosity (NYDA) to the topical application of a 0.05 % solution of KMnO4 in 47 school children in an endemic area in rural Kenya. The efficacy of the treatment was assessed during a follow up period of seven days using viability signs of the embedded parasites, alterations in the natural development of lesion morphology and the degree of local inflammation as outcome measures. Seven days after treatment, in the Dimeticone group 78 % (95 % CI 67–86%) of the parasites had lost all signs of viability as compared to 39 % (95 % CI 28– 52%) in the KMnO4 group (p,0.001). In the Dimeticone group 90 % (95 % CI 80–95%) of the penetrated sand fleas showed an abnormal development already after 5 days, compared to 53 % (95 % CI 40–66%; p,0.001) in the KMnO4 group. Seven days after treatment, signs of local skin inflammation had significantly decreased in the Dimeticone group (p,0.001). This study identified the topical application of Dimeticones of low viscosity (NYDA) as an effective means to kill embedded san
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Treatment of Tungiasis with Dimeticone: A Proof-of-Principle Study in Rural Kenya
2014Co-Authors: Marlene Thielecke, Per Nordin, Nicholas Ngomi, Hermann FeldmeierAbstract:Tungiasis (sand flea disease) is a neglected tropical disease, prevalent in resource-poor communities in South America and sub-Saharan Africa. It is caused by an inflammatory response against penetrated female sand fleas (Tunga penetrans) embedded in the skin of the host. Although associated with debilitating acute and chronic morbidity, there is no proven effective drug treatment. By consequence patients attempt to remove embedded sand fleas with non-sterile sharp instruments, such as safety pins, a procedure that represents a health threat by itself. In this proof-of-principle study we compared the topical application of a mixture of two Dimeticones of low viscosity (NYDA) to the topical application of a 0.05% solution of KMnO4 in 47 school children in an endemic area in rural Kenya. The efficacy of the treatment was assessed during a follow up period of seven days using viability signs of the embedded parasites, alterations in the natural development of lesion morphology and the degree of local inflammation as outcome measures. Seven days after treatment, in the Dimeticone group 78% (95% CI 67–86%) of the parasites had lost all signs of viability as compared to 39% (95% CI 28–52%) in the KMnO4 group (p
Ian F Burgess - One of the best experts on this subject based on the ideXlab platform.
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Randomised, Controlled, Assessor Blind Trial Comparing 4 % Dimeticone Lotion with 0.5 % Malathion Liquid for Head
2016Co-Authors: Louse Infestation, Ian F Burgess, Peter N. Lee, Geraldine MatlockAbstract:Background. Malathion 0.5 % has been the most prescribed pediculicide in the United Kingdom for around 10 years, and is widely used in Europe and North America. Anecdotal reports suggest malathion treatments are less effective than formerly, but this has not been confirmed clinically. This study was designed to determine whether malathion is still effective and if 4% Dimeticone lotion is a more effective treatment for head louse infestation. Methodology/Principal Findings. We designed this study as an assessor blinded, randomised, controlled, parallel group trial involving 58 children and 15 adults with active head louse infestation. Each participant received two applications 7 days apart of either 4 % Dimeticone lotion, applied for 8 hours or overnight, or 0.5 % malathion liquid applied for 12 hours or overnight. All treatment and check-up visits were conducted in participants ’ homes. Cure of infestation was defined as no evidence of head lice after the second treatment. Some people were found free from lice but later reinfested. Worst case, intention to treat, analysis found Dimeticone was significantly more effective than malathion, with 30/43 (69.8%) participants cured using Dimeticone compared with 10/30 (33.3%) using malathion (p,0.01, difference 36.4%, 95 % confidence interval 14.7 % to 58.2%). Per protocol analysis showed cure rates of 30/39 (76.9%) and 10/29 (34.5%) respectively. Irritant reactions were observed in only two participants, both treated with malathion. Conclusions/Significance. We concluded that, although malathion liquid is still effective for some people, Dimeticone lotion offers a significantly more effective alternative treatment for most people. Trial Registration
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ral ssBioMed CentBMC Pharmacology Open AcceResearch article The mode of action of Dimeticone 4 % lotion against head lice,
2016Co-Authors: Ian F BurgessAbstract:Background: Treatment of head lice using physically acting preparations based on silicones is currently replacing insecticide use due to widespread resistance to neurotoxic agents. It has been postulated that some products act by asphyxiation, although the limited experimental evidence and the anatomy of the louse respiratory system suggest this is unlikely. Results: Observation over several hours of lice treated using 4 % high molecular weight Dimeticone in a volatile silicone base showed that, although rapidly immobilised initially, the insects still exhibited small movements of extremities and death was delayed. One common effect of treatment is inhibition of the louse's ability to excrete water by transpiration through the spiracles. Inability to excrete water that is ingested as part of the louse blood meal appears to subject the louse gut to osmotic stress resulting in rupture. Scanning electron microscopy coupled with X-ray microanalysis to detect silicon showed Dimeticone lotion is deposited in the spiracles and distal region of the tracheae of lice and in some cases blocks the lumen or opening entirely. Conclusion: This work raises doubts that lice treated using Dimeticone preparations die from anoxia despite blockage of the outer respiratory tract because movements can be observed fo
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Letters to the editor Re: Treatment of Parasitic Skin Diseases with Dimeticones A New Family of Compounds with a Purely Physical Mode of Action
2016Co-Authors: Ian F BurgessAbstract:Abstract: The article on use of Dimeticone for treatment of epidermal parasitic skin diseases is potentially confusing and misleading because, in a practical sense, only head louse infestation can be treated with this material. Scabies mites are unaffected by silicones and use of Dimeticone against other ectoparasites may have unwanted side effects such as anaphylactiform reactions or increased risk of pathogen transmission
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Re: Treatment of Parasitic Skin Diseases with Dimeticones A New Family of Compounds with a Purely Physical Mode of Action
Tropical Medicine and Health, 2015Co-Authors: Ian F BurgessAbstract:The article on use of Dimeticone for treatment of epidermal parasitic skin diseases is potentially confusing and misleading because, in a practical sense, only head louse infestation can be treated with this material. Scabies mites are unaffected by silicones and use of Dimeticone against other ectoparasites may have unwanted side effects such as anaphylactiform reactions or increased risk of pathogen transmission.
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0.4% Dimeticone spray, a novel physically acting household treatment for control of cat fleas.
Veterinary parasitology, 2013Co-Authors: Ian M Jones, Elizabeth R Brunton, Ian F BurgessAbstract:The cat flea, Ctenocephalides felis, is the most important ectoparasite of cats and dogs worldwide as a cause of irritation and health problems. Most products to control these pests in the household environment rely upon a combination of neurotoxic insecticides and insect growth regulators to inhibit development of flea eggs and larvae into adults. However, some of these are affected by problems of insecticide resistance as well as public concerns about their potential for toxicity in domestic use. Heavy synthetic oils, like the siloxane Dimeticone, are currently widely used to treat human ectoparasite infestations, acting by a physical mode of action, and have been used in a variety of presentations for killing all life stages of fleas. We have investigated the activity of low concentrations of high molecular weight Dimeticone in a volatile silicone base for ability to immobilise flea life stages without asphyxiating them. We found that cat flea adults and larvae were immobilised by a surface film of Dimeticone that inhibited movement of cuticular joints, apparently forming an effective sticky trap. When cocoons were treated the fleas continued to develop within the pupae but failed to emerge. An aerosol spray incorporating 0.4% concentration of Dimeticone, for use as a residual household treatment, showed no significant difference in knock down capability compared with that of a widely used pyriproxifen/permethrin spray in a repeat challenge test, with effects persisting to inhibit adult flea emergence in the test arena area for more than 3 weeks after application.
Nazma A Burgess - One of the best experts on this subject based on the ideXlab platform.
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single application of 4 Dimeticone liquid gel versus two applications of 1 permethrin creme rinse for treatment of head louse infestation a randomised controlled trial
BMC Dermatology, 2013Co-Authors: Elizabeth R Brunton, Nazma A BurgessAbstract:Background A previous study indicated that a single application of 4% Dimeticone liquid gel was effective in treating head louse infestation. This study was designed to confirm this in comparison with two applications of 1% permethrin.
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Single application of 4% Dimeticone liquid gel versus two applications of 1% permethrin creme rinse for treatment of head louse infestation: a randomised controlled trial
BMC Dermatology, 2013Co-Authors: Elizabeth R Brunton, Nazma A BurgessAbstract:Background A previous study indicated that a single application of 4% Dimeticone liquid gel was effective in treating head louse infestation. This study was designed to confirm this in comparison with two applications of 1% permethrin. Methods We have performed a single centre parallel group, randomised, controlled, open label, community based trial, with domiciliary visits, in Cambridgeshire, UK. Treatments were allocated through sealed instructions derived from a computer generated list. We enrolled 90 children and adults with confirmed head louse infestation analysed by intention to treat (80 per-protocol after 4 drop outs and 6 non-compliant). The comparison was between 4% Dimeticone liquid gel applied once for 15 minutes and 1% permethrin creme rinse applied for 10 minutes, repeated after 7 days as per manufacturer’s directions. Evaluated by elimination of louse infestation after completion of treatment application regimen. Results Intention to treat comparison of a single Dimeticone liquid gel treatment with two of permethrin gave success for 30/43 (69.8%) of the Dimeticone liquid gel group and 7/47 (14.9%) of the permethrin creme rinse group (OR 13.19, 95% CI 4.69 to 37.07) (p
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single application of 4 Dimeticone liquid gel versus two applications of 1 permethrin creme rinse for treatment of head louse infestation a randomised controlled trial
BMC Dermatology, 2013Co-Authors: Ian F Burgess, Elizabeth R Brunton, Nazma A BurgessAbstract:A previous study indicated that a single application of 4% Dimeticone liquid gel was effective in treating head louse infestation. This study was designed to confirm this in comparison with two applications of 1% permethrin. We have performed a single centre parallel group, randomised, controlled, open label, community based trial, with domiciliary visits, in Cambridgeshire, UK. Treatments were allocated through sealed instructions derived from a computer generated list. We enrolled 90 children and adults with confirmed head louse infestation analysed by intention to treat (80 per-protocol after 4 drop outs and 6 non-compliant). The comparison was between 4% Dimeticone liquid gel applied once for 15 minutes and 1% permethrin creme rinse applied for 10 minutes, repeated after 7 days as per manufacturer’s directions. Evaluated by elimination of louse infestation after completion of treatment application regimen. Intention to treat comparison of a single Dimeticone liquid gel treatment with two of permethrin gave success for 30/43 (69.8%) of the Dimeticone liquid gel group and 7/47 (14.9%) of the permethrin creme rinse group (OR 13.19, 95% CI 4.69 to 37.07) (p < 0.001). Per protocol results were similar with 27/35 (77.1%) success for Dimeticone versus 7/45 (15.6%) for permethrin. Analyses by household gave essentially similar outcomes. The study showed one 15 minute application of 4% Dimeticone liquid gel was superior to two applications of 1% permethrin creme rinse (p < 0.001). The low efficacy of permethrin suggests it should be withdrawn. Current Controlled Trials ISRCTN88144046 .
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Dimeticone 4% liquid gel found to kill all lice and eggs with a single 15 minute application.
BMC research notes, 2011Co-Authors: Ian F Burgess, Nazma A BurgessAbstract:Background: Dimeticone 4% lotion is an effective and widely accepted treatment for head louse infestation. However, it is a highly mobile fluid that some people find difficult to apply and is mainly left on the hair for 8 hours or overnight. User preference is for a more manageable and viscous product that can be used with a short application time. Findings: This proof of concept study in 41 people investigated Dimeticone 4% liquid gel, a product that is easier to apply than the lotion, applied for 15 minutes on two occasions a week apart. We found that head lice were eliminated from all participants following the first application of product. We did not find lice of any stage on any participant during four post treatment assessments and particularly, unlike other treatments, no young nymphs on days 1 and 6 prior to the second treatment, indicating ovicidal as well as pediculicidal activity. Conclusions: Dimeticone 4% liquid gel has demonstrated efficacy greater than other similar products and the evidence obtained indicates elimination of head louse infestation with a single 15 minute application.
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Dimeticone 4% liquid gel found to kill all lice and eggs with a single 15 minute application
BMC Research Notes, 2011Co-Authors: Ian F Burgess, Nazma A BurgessAbstract:Background Dimeticone 4% lotion is an effective and widely accepted treatment for head louse infestation. However, it is a highly mobile fluid that some people find difficult to apply and is mainly left on the hair for 8 hours or overnight. User preference is for a more manageable and viscous product that can be used with a short application time. Findings This proof of concept study in 41 people investigated Dimeticone 4% liquid gel, a product that is easier to apply than the lotion, applied for 15 minutes on two occasions a week apart. We found that head lice were eliminated from all participants following the first application of product. We did not find lice of any stage on any participant during four post treatment assessments and particularly, unlike other treatments, no young nymphs on days 1 and 6 prior to the second treatment, indicating ovicidal as well as pediculicidal activity. Conclusions Dimeticone 4% liquid gel has demonstrated efficacy greater than other similar products and the evidence obtained indicates elimination of head louse infestation with a single 15 minute application. Trial registration Current Controlled Trials ISRCTN59227204
Jorg Heukelbach - One of the best experts on this subject based on the ideXlab platform.
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high efficacy of a Dimeticone based pediculicide following a brief application in vitro assays and randomized controlled investigator blinded clinical trial
BMC Dermatology, 2019Co-Authors: Jorg Heukelbach, Doerte Wolf, John Marshall Clark, Hans Dautel, Kristina RoeschmannAbstract:Increasing resistance of head lice against neurotoxic agents and safety concerns have led to the search for treatment alternatives. Dimeticones with a physical mode of action are safe, and bear a reduced risk for the development of resistance. We performed in vitro bioassays to assess pediculicidal and ovicidal activities of a new Dimeticone-based product, and a randomized controlled clinical trial to assess efficacy, following 10 min application. Of 153 individuals screened, 100 participants with active head louse infestations were randomly assigned to treatment with either a Dimeticone-based test product, or a 0.5% permethrin-based reference product (50 participants per group). Participants received two topical applications of either the test (10 min) or reference products (45 min) at days 0 and 7 or 8. Outcome measures included the efficacies of treatment and their safety, as well as global and local tolerability at baseline, and days 1, 7, and 10. After 10 min exposure, all lice treated with the Dimeticone test product were classified as non-viable in the in vitro assay. Ovicidal activity after treatment of eggs with the Dimeticone test product was 96.8%. In the clinical trial, 96 patients completed all study visits. In the full analysis set (FAS) population, on day 1 after one application, 98% of patients were cured in the test group, as compared to 84% cured in the reference group. All participants in both groups were free of head lice on day 10, following two applications (100% cure rate). In total, 42 adverse events (AEs) in 23 patients of both treatment groups were recorded, with the majority of AEs classified as mild. We have shown a high level of pediculicidal and ovicidal activity, and clinical efficacy and safety, of a brief application of a new Dimeticone-based product. The short application time and reduced risk for the development of resistance are key drivers for improved patients’ compliance. EU Clinical Trials Register EudraCT 2016–004635-20 . Registered 14 November 2016.
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High efficacy of a Dimeticone-based pediculicide following a brief application: in vitro assays and randomized controlled investigator-blinded clinical trial
BMC Dermatology, 2019Co-Authors: Jorg Heukelbach, Doerte Wolf, John Marshall Clark, Hans Dautel, Kristina RoeschmannAbstract:Background Increasing resistance of head lice against neurotoxic agents and safety concerns have led to the search for treatment alternatives. Dimeticones with a physical mode of action are safe, and bear a reduced risk for the development of resistance. Methods We performed in vitro bioassays to assess pediculicidal and ovicidal activities of a new Dimeticone-based product, and a randomized controlled clinical trial to assess efficacy, following 10 min application. Of 153 individuals screened, 100 participants with active head louse infestations were randomly assigned to treatment with either a Dimeticone-based test product, or a 0.5% permethrin-based reference product (50 participants per group). Participants received two topical applications of either the test (10 min) or reference products (45 min) at days 0 and 7 or 8. Outcome measures included the efficacies of treatment and their safety, as well as global and local tolerability at baseline, and days 1, 7, and 10. Results After 10 min exposure, all lice treated with the Dimeticone test product were classified as non-viable in the in vitro assay. Ovicidal activity after treatment of eggs with the Dimeticone test product was 96.8%. In the clinical trial, 96 patients completed all study visits. In the full analysis set (FAS) population, on day 1 after one application, 98% of patients were cured in the test group, as compared to 84% cured in the reference group. All participants in both groups were free of head lice on day 10, following two applications (100% cure rate). In total, 42 adverse events (AEs) in 23 patients of both treatment groups were recorded, with the majority of AEs classified as mild. Conclusions We have shown a high level of pediculicidal and ovicidal activity, and clinical efficacy and safety, of a brief application of a new Dimeticone-based product. The short application time and reduced risk for the development of resistance are key drivers for improved patients’ compliance. Trial registration EU Clinical Trials Register EudraCT 2016–004635-20 . Registered 14 November 2016.
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1874-3722/10 2010 Bentham Open Open Access Dimeticone-Based Pediculicides: A Physical Approach to Eradicate Head Lice
2016Co-Authors: Jorg Heukelbach, Fabíola A Oliveira, Joachim Richter, Dieter HäussingerAbstract:Abstract: Resistance of head lice to insecticides with a neurotoxic mode of action, such as permethrin and malathion, is increasing in incidence and geographic extent. As a consequence, physically acting pediculicidal products have emerged. Dimeticones are synthetic silicone oils of low surface tension and can therefore coat most surfaces, thus also killing head lice (Pediculus humanus capitis) by physical means. Considering this mode of action, the development of head lice resistance in the future is very unlikely. In this review, ex vivo and clinical evidence on the efficacy of Dimeticones against head lice is presented. Besides the high adulticidal and excellent ovicidal ex vivo efficacy, clinical efficacy of high concentrated Dimeticone has been shown. We conclude that Dimeticone-based products are a safe and effective option for those patients who prefer not to use pediculicides with a neurotoxic mode of action, especially in areas where resistances of head lice against permethrin and malathion-based products have been reported, or are suspected
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Ovicidal efficacy of high concentration Dimeticone: a new era of head lice treatment.
Journal of the American Academy of Dermatology, 2011Co-Authors: Jorg Heukelbach, Richard Speare, Susanne Sonnberg, Heiko Becher, Iana L. Araujo De Melo, Fabiola Araujo OliveiraAbstract:[Extract] Nontoxic compounds that kill head lice, such as the silicone oil Dimeticone, are promising approaches for control. Here we present ovicidal efficacy of high concentration Dimeticones in a comparative bioassay.
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Dimeticone-based pediculicides: a physical approach to eradicate head lice
The Open Dermatology Journal, 2010Co-Authors: Jorg Heukelbach, Fabiola Araujo Oliveira, Joachim Richter, Dieter HäussingerAbstract:Resistance of head lice to insecticides with a neurotoxic mode of action, such as permethrin and malathion, is increasing in incidence and geographic extent. As a consequence, physically acting pediculicidal products have emerged. Dimeticones are synthetic silicone oils of low surface tension and can therefore coat most surfaces, thus also killing head lice (Pediculus humanus capitis) by physical means. Considering this mode of action, the development of head lice resistance in the future is very unlikely. In this review, ex vivo and clinical evidence on the efficacy of Dimeticones against head lice is presented. Besides the high adulticidal and excellent ovicidal ex vivo efficacy, clinical efficacy of high concentrated Dimeticone has been shown. We conclude that Dimeticone-based products are a safe and effective option for those patients who prefer not to use pediculicides with a neurotoxic mode of action, especially in areas where resistances of head lice against permethrin and malathion-based products have been reported, or are suspected.
Krystyna Mojsiewiczpienkowska - One of the best experts on this subject based on the ideXlab platform.
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size exclusion chromatography with evaporative light scattering detection as a method for speciation analysis of polydimethylsiloxanes iii identification and determination of Dimeticone and simeticone in pharmaceutical formulations
Journal of Pharmaceutical and Biomedical Analysis, 2012Co-Authors: Krystyna MojsiewiczpienkowskaAbstract:Abstract The pharmaceutical industry is one of the more important sectors for the use of polydimethylsiloxanes (PDMS), which belong to the organosilicon polymers. In drugs for internal use, they are used as an active pharmaceutical ingredient (API) called Dimeticone or simeticone. Due to their specific chemical nature, PDMS can have different degrees of polymerization, which determine the molecular weight and viscosity. The Pharmacopoeial monographs for Dimeticone and simeticone, only give the permitted polymerization and viscosity range. It is, however, essential to know also the degree of polymerization or the specific molecular weight of PDMS that are present in pharmaceutical formulations. In the literature there is information about the impact of particle size, and thus molecular weight, on the toxicity, absorption and migration in living organisms. This study focused on the use of a developed method – the exclusion chromatography with evaporative light scattering detector (SEC-ELSD) – for identification and determination of Dimeticone and simeticone in various pharmaceutical formulations. The method had a high degree of specificity and was suitable for speciation analysis of these polymers. So far the developed method has not been used in the control of medicinal products containing Dimeticone or simeticone.
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size exclusion chromatography with evaporative light scattering detection as a method for speciation analysis of polydimethylsiloxanes ii validation of the method for analysis of pharmaceutical formulations
Journal of Pharmaceutical and Biomedical Analysis, 2011Co-Authors: Krystyna MojsiewiczpienkowskaAbstract:The aim of this study was to demonstrate the usefulness of the size exclusion chromatography with evaporative light scattering detection (SEC-ELSD) method in the identification and quantitative analysis of polydimethylsiloxanes (PDMS). The process of validation for the method was conducted, and the values obtained were compared with the acceptance criteria. Particularly important was the conclusion that SEC-ELSD method showed a high specificity for PDMS. PDMS is an organosilicon polymer and for this reason, it does not exist as a concrete chemical species. Depending on the length of the chain, PDMS can be toxic for organism. So far, the SEC-ELSD method has not been applied for the control of pharmaceutical products containing such PDMS as Dimeticone or simeticone. The safety of use and effectiveness of such pharmaceutical products relies on the control of their quality. Therefore, the analytical methods and procedures that meet acceptance criteria for qualitative and quantitative analysis of the PDMS should be used. In the case of the analysis of pharmaceutical products, the acceptance criteria are established and recommended by, for example, the Pharmacopoeias, the U.S. Food and Drug Administration (FDA), the International Conference on Harmonisation (ICH) and the World Health Organization (WHO). The progress of knowledge, however, requires the development of new analytical tools which are able to solve incoming problems. In the case of pharmaceutical formulations containing PDMS, which are used not only by adults but also by children, it is necessary to use analytical methods which are characterized by a high specificity.