The transport of the antiparasitic agents, ivermectin, selamectin and moxidectin was studied in human intestinal epithelial cell monolayers (Caco-2) and canine peripheral blood lymphocytes (PBL). Both models expressed the mdr1-coded 170 kDa ATP-binding cassette (ABC) transporter P-glycoprotein (P-gp). Fluxes of the P-gp substrate rhodamine-123 (Rh-123) across Caco-2 monolayers showed that ivermectin and selamectin acted as potent P-gp inhibitors with IC50 values of 0.1 microm. The transport of radiolabelled ivermectin, selamectin and moxidectin through Caco-2 monolayers showed that ivermectin, selamectin and moxidectin were P-gp substrates with secretory/absorptive ratios of 7.5, 4.7 and 2.6 respectively. Secretory transport of [3H]-ivermectin and [3H]-selamectin was blocked by the P-gp inhibitor, verapamil. Ivermectin and selamectin inhibited the efflux of Rh-123 from PBL and the concentration of inhibition was similar to that of verapamil. In contrast, moxidectin did not have a significant effect on Rh-123 efflux from PBL. The data suggest that ivermectin and selamectin are potent P-gp substrates, while moxidectin is a weak one.[2]

The transport of the antiparasitic agents, ivermectin, selamectin and moxidectin was studied in human intestinal epithelial cell monolayers (Caco-2) and canine peripheral blood lymphocytes (PBL). Both models expressed the mdr1-coded 170 kDa ATP-binding cassette (ABC) transporter P-glycoprotein (P-gp). Fluxes of the P-gp substrate rhodamine-123 (Rh-123) across Caco-2 monolayers showed that ivermectin and selamectin acted as potent P-gp inhibitors with IC50 values of 0.1 microm. The transport of radiolabelled ivermectin, selamectin and moxidectin through Caco-2 monolayers showed that ivermectin, selamectin and moxidectin were P-gp substrates with secretory/absorptive ratios of 7.5, 4.7 and 2.6 respectively. Secretory transport of [3H]-ivermectin and [3H]-selamectin was blocked by the P-gp inhibitor, verapamil. Ivermectin and selamectin inhibited the efflux of Rh-123 from PBL and the concentration of inhibition was similar to that of verapamil. In contrast, moxidectin did not have a significant effect on Rh-123 efflux from PBL. The data suggest that ivermectin and selamectin are potent P-gp substrates, while moxidectin is a weak one.[2]

To assess chemotherapeutic efficacy of topical selamectin, eight Brugia malayi and six Brugia pahangi microfilaremic cats were treated with a single administration of topical selamectin. For chemoprophylactic efficacy assessment, a single application of topical selamectin was administrated to 9 healthy, uninfected cats. The cats in both groups were subjected to a monthly blood testing for microfilariae and filarial DNA for 1 year. Topical selamectin treatment in B. malayi and B. pahangi microfilaremic cats showed 100% effectivity in eradicating microfilaremia but only 78.5% effectivity in eliminating filarial DNA. In the chemoprophylactic group, selamectin demonstrated 66.7% efficacy in preventing B. malayi infection. Our findings suggest that a single administration of 6 mg/kg topical selamectin given every two months could effectively prevent B. malayi infection. Application of topical selamectin twice a year could block circulating microfilariae. [1]

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Chemotherapeutic Efficacy: A single topical administration of 6 mg/kg selamectin on days 1, 15, 30, and 45 showed 100% efficacy in eliminating circulating microfilariae in cats naturally infected with Brugia malayi (n=8) and Brugia pahangi (n=6). However, the efficacy in eliminating filarial DNA (indicative of adult worm presence) was 78.5%. Microfilarial levels at 1 month post-treatment were significantly lower than pre-treatment levels (P = 0.009). [1]
Chemoprophylactic Efficacy: A single topical dose of 6 mg/kg selamectin demonstrated 66.7% efficacy (6 out of 9 cats remained negative) in preventing B. malayi infection (negative for both microfilariae and DNA) in healthy, uninfected cats over a 12-month observation period under field conditions. One cat became DNA positive at 2 months and microfilariae positive at 8 months post-prophylaxis. [1]

The provided literature does not contain detailed descriptions of enzyme activity assays (e.g., kinase activity, SPR, ITC) or target binding experiments for selamectin. [1]

Chemotherapeutic Study: Fourteen cats naturally infected with either Brugia malayi (n=8) or Brugia pahangi (n=6) were treated with a topical application of selamectin at a dosage of 6 mg/kg. The drug was applied to the skin at the base of the neck on days 1, 15, 30, and 45. Cats were observed at 1, 2, 4, and 6 hours after each treatment for adverse events. Blood samples were collected monthly for 12 months for microfilariae detection via Giemsa-stained thick blood smear and filarial DNA detection via high-resolution melting real-time PCR. [1]
Chemoprophylactic Study:Nine healthy, uninfected cats received a single topical dose of 6 mg/kg selamectin at the beginning of the study. Cats were observed for adverse events at 1, 2, 4, and 6 hours post-treatment. Monthly blood collection and testing (thick blood smear and PCR) were performed for 12 months to monitor for infection. [1]
General Protocol: The study was conducted under field conditions. Drug administration and animal care were performed by the cat owners at their households after being trained. Clinical examinations were performed at the beginning and during the study. Pregnant, lactating, or systemically ill cats were excluded. [1]

Selamectin cannot cross the blood-brain barrier in mammals. It can achieve large-volume distribution, tissue penetration, and accumulation in sebaceous glands, thus acting as a drug reservoir. [1]

Selamectin is considered safe for cats. It is a modified version of other macrolide drugs, such as ivermectin, to improve its safety. Topical application has been reported to be less toxic than oral or injectable ivermectin. In this study, researchers observed adverse reactions in cats at 1, 2, 4, and 6 hours after treatment (mydriasis, salivation, depression, anorexia, vomiting, diarrhea, unsteady gait, ocular discharge, strabismus, abnormal breathing, muscle tremors, pruritus). [1]

[1]. First study of topical selamectin efficacy for treating cats naturally infected with Brugia malayi and Brugia pahangi under field conditions. Parasitol Res. 2019 Apr;118(4):1289-1297.

[2]. Selamectin is a potent substrate and inhibitor of human and canine P-glycoprotein. J Vet Pharmacol Ther. 2005 Jun;28(3):257-65.

Selamectin is a milbemycin class of drugs. Selamectin is a topical anthelmintic used to treat and prevent heartworm, flea, ear mite, scabies, and certain tick infections in dogs and cats, and to prevent heartworm, flea, ear mite, hookworm, and roundworm infections in cats. It can also eliminate two lungworms in cats and one in dogs. This drug is distributed by Zoetis, a former subsidiary of Pfizer. Its structure is related to ivermectin and milbemycin. Selamectin is not approved for human use. See also: Salorana; Selamectin (ingredients). Indications: Cats and dogs: For the treatment and prevention of flea infestations caused by the genus Ctenocephalides after a single dose, with effects lasting one month. This is due to the product's adult, larval, and ovicidal properties. The product retains its ovicidal effect for up to 3 weeks after administration. By reducing flea populations, monthly treatment of pregnant and lactating animals also helps prevent flea infestation in puppies before 7 weeks of age. This product can be used as part of a flea allergy dermatitis treatment regimen; its ovicidal and larval-killing effects help control existing environmental flea infestations in areas accessible to the animal. Monthly administration can prevent canine heartworm disease caused by Dirofilaria immitis. This product is safe for use in animals already infected with adult worms; however, according to good veterinary practice, it is recommended that all animals aged 6 months and older living in countries with vectors be tested for adult Dirofilaria immitis infection before starting this product. Even with monthly use of this product, regular testing for adult Dirofilaria immitis infection in dogs is recommended as an important part of a heartworm prevention strategy. This product is ineffective against adult Dirofilaria immitis. Used to treat ear mites (Otodectes cynotis). Cats: Used to treat cat fleas (Felicola subrostratus), adult roundworms (Toxocara cati), adult hookworms (Ancylostoma tubaeforme), cat fleas (Trichodectes canis), and scabies (caused by Sarcoptes scabiei). A single dose can treat and prevent flea infestations caused by Ctenocephalides spp., with effects lasting up to one month. This is due to the product's adult, larval, and ovicidal properties. The product retains its ovicidal effect for up to three weeks after administration. Monthly treatment of pregnant and lactating animals by reducing flea populations also helps prevent flea infestations in pups before seven weeks of age. This product can be used as part of a flea allergy dermatitis treatment regimen; its ovicidal and larval-killing effects help control existing environmental flea infestations in the animal's living area. Monthly administration can prevent canine heartworm disease caused by Dirofilaria immitis. This product is safe for use in animals already infected with adult canine heartworms. However, according to good veterinary practice, it is recommended that all animals aged 6 months and older living in countries with vectors be tested for adult canine heartworm infection before starting this product. Even with monthly administration, regular testing for adult canine heartworm infection in dogs is recommended as an important part of a canine heartworm prevention strategy. This product is ineffective against adult canine heartworms. It is used to treat ear mites (Otodectes cynotis). Cats: Treatment of feline fleas (Felicola subrostratus); treatment of adult feline toxocara cati; treatment of adult canine hookworm (Ancylostoma tubaeforme). Dogs: Treatment of canine fleas (Trichodectes canis); treatment of scabies (caused by Sarcoptes scabiei); treatment of adult canine toxocara canis.
Cats and Dogs: A single dose can treat and prevent flea infestations caused by Ctenocephalides spp., with effects lasting up to one month. This is due to the product's adult, larval, and ovicidal properties. Ovicidal activity persists for up to 3 weeks after administration. Monthly treatment of pregnant and lactating animals by reducing flea populations also helps prevent flea infestations in pups before 7 weeks of age. This product can be used as part of a flea allergy dermatitis treatment regimen; its ovicidal and larval-killing effects help control existing environmental flea infestations in areas accessible to the animal. Monthly administration can prevent canine heartworm disease caused by Dirofilaria immitis. Stronghold is safe for use in animals already infected with adult Dirofilaria immitis; however, according to good veterinary practice, it is recommended that all animals aged 6 months and older living in countries with vectors be tested for adult Dirofilaria immitis infection before initiating treatment with Stronghold. Even with monthly Stronghold administration, regular testing for adult canine heartworm infection in dogs is recommended as an important part of the canine heartworm prevention strategy. This product is ineffective against adult canine heartworm. Used to treat ear mites (Otodectes cynotis). Cats: Treatment of felice (Felicola subrostratus) infection; treatment of adult Toxocara cati; treatment of adult Ancylostoma tubaeforme. Dogs: Treatment of canine lice (Trichodectes canis) infection; treatment of scabies (caused by Sarcoptes scabiei); treatment of adult Toxocara canis.

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Selamectin is a semi-synthetic macrolide drug widely used for the prevention of canine heartworm (Dirofilaria immitis) infection. [1]
This drug can rapidly clear microfilariae and inhibit the number of microfilariae for months by inducing long-term infertility in female adults through the inhibition of the secretion of immunomodulatory molecules. [1]
This study is the first to explore the efficacy of topical selamectin in treating feline lymphatic filariasis (Malayan filariasis and Pasteurella multocida). [1]
The results showed that topical application of selamectin every two months effectively prevented Malayan filariasis infection, and twice-yearly application blocked the circulation of microfilariae in cats. This helps guide the treatment of brucellosis in cats (as viral hosts), for which there were previously no treatment guidelines. [1]
In endemic areas, cats are natural hosts of zoonotic Malayan filariasis and potential Pasteurella multocida, therefore controlling infection in these animals is crucial to reducing the risk of human transmission. [1]

C43H63NO11

769.97

769.44

165108-07-6

9578507

White to off-white solid powder

1.4±0.1 g/cm3

917.0±65.0 °C at 760 mmHg

508.4±34.3 °C

0.0±0.6 mmHg at 25°C

1.618

6.83

3

12

4

55

1550

14

C[C@H]1CC[C@]2(C[C@@H]3C[C@H](O2)C/C=C(/[C@H]([C@H](/C=C/C=C/4\CO[C@H]\5[C@@]4([C@@H](C=C(/C5=N/O)C)C(=O)O3)O)C)O[C@H]6C[C@@H]([C@H]([C@@H](O6)C)O)OC)\C)O[C@@H]1C7CCCCC7

AFJYYKSVHJGXSN-XHKIUTQPSA-N

InChI=1S/C43H63NO11/c1-24-11-10-14-30-23-50-40-36(44-48)27(4)19-33(43(30,40)47)41(46)52-32-20-31(16-15-25(2)38(24)53-35-21-34(49-6)37(45)28(5)51-35)54-42(22-32)18-17-26(3)39(55-42)29-12-8-7-9-13-29/h10-11,14-15,19,24,26,28-29,31-35,37-40,45,47-48H,7-9,12-13,16-18,20-23H2,1-6H3/b11-10+,25-15+,30-14+,44-36-/t24-,26-,28-,31+,32-,33-,34-,35-,37-,38-,39-,40+,42+,43+/m0/s1

(1R,4S,5'S,6R,6'S,8R,10E,12S,13S,14E,16E,20R,21Z,24S)-6'-cyclohexyl-24-hydroxy-21-hydroxyimino-12-[(2R,4S,5S,6S)-5-hydroxy-4-methoxy-6-methyloxan-2-yl]oxy-5',11,13,22-tetramethylspiro[3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene-6,2'-oxane]-2-one

Selamectin , UK-124114 UNII-A2669OWX9N ,

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)