Radiolabeled selamectin was found to be a P-glycoprotein (P-gp) substrate with a secretion/absorption ratio of 4.7 when it was transported across the Caco-2 monolayer. In peripheral blood lymphocytes (PBL), selamectin inhibits Rh-123 efflux at a dose that is comparable to verapamil's inhibitory effect [2].

B can be successfully avoided with topical selamectin 6 mg/kg once every two months. infection in cats with malayi. Twice a year, topical selamectin can stop microfilariae from circulating [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.
Selamectin is a topical parasiticide and antihelminthic used on dogs and cats to treat and prevent infections of heartworms, fleas, ear mites, sarcoptic mange, and certain types of ticks in dogs as well as prevent heartworms, fleas, ear mites, hookworms, and roundworms in cats. It also removes 2 types of lungworm in cats and one type of lungworm in dogs. It is distributed by Zoetis, a former Pfizer subsidiary. It is structurally related to ivermectin and milbemycin. Selamectin is not approved for human use.
See also: Sarolaner; Selamectin (component of).

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Drug Indication
Cats and dogs: Treatment and prevention of flea infestations caused by Ctenocephalides spp. for one month following a single administration. This is as a result of the adulticidal, larvicidal and ovicidal properties of the product. The product is ovicidal for 3 weeks after administration. Through a reduction in the flea population, monthly treatment of pregnant and lactating animals will also aid in the prevention of flea infestations in the litter up to seven weeks of age. The product can be used as part of a treatment strategy for flea allergy dermatitis and through its ovicidal and larvicidal action may aid in the control of existing environmental flea infestations in areas to which the animal has access. Prevention of heartworm disease caused by Dirofilaria immitis with monthly administration. The product may be safely administered to animals infected with adult heartworms, however, it is recommended, in accordance with good veterinary practice, that all animals 6 months of age or more living in countries where a vector exists should be tested for existing adult heartworm infections before beginning medication with the product. It is also recommended that dogs should be tested periodically for adult heartworm infections, as an integral part of a heartworm prevention strategy, even when the product has been administered monthly. This product is not effective against adult D. immitis. Treatment of ear mites (Otodectes cynotis). Cats: Treatment of biting lice infestations (Felicola subrostratus)Treatment of adult roundworms (Toxocara cati)Treatment of adult intestinal hookworms (Ancylostoma tubaeforme)Treatment of biting lice infestations (Trichodectes canis)Treatment of sarcoptic mange (caused by Sarcoptes scabiei)
Treatment and prevention of flea infestations caused by Ctenocephalides spp. for one month following a single administration. This is as a result of the adulticidal, larvicidal and ovicidal properties of the product. The product is ovicidal for 3 weeks after administration. Through a reduction in the flea population, monthly treatment of pregnant and lactating animals will also aid in the prevention of flea infestations in the litter up to seven week of age. The product can be used as part of a treatment strategy for flea allergy dermatitis and through its ovicidal and larvicidal action may aid in the control of existing environmental flea infestations in area to which the animal has access. Prevention of heartworm disease caused by Dirofilaria immitis with monthly administration. The product may be safely administered to animals infected with adult heartworms, however, it is recommended, in accordance with good veterinary practice, that all animals 6 months of age or more living in countries where a vector exists should be tested for existing adult heartworm infections before beginning medication with the product. It is also recommended that dogs should be tested periodically for adult heartworm infections, as an integral part of a heartworm prevention strategy, even when the product has been administered monthly. This product is not effective against adult D. immitis. Treatment of ear mites (Otodectes cynotis). Cats: Treatment of biting lice infestations (Felicola subrostratus)Treatment of adult roundworms (Toxocara cati)Treatment of adult intestinal hookworms (Ancylostoma tubaeforme). Dogs: Treatment of biting lice infestations (Trichodectes canis)Treatment of sarcoptic mange (caused by Sarcoptes scabiei)Treatment of adult intestinal roundworms (Toxocara canis).
Cats and dogs: Treatment and prevention of flea infestations caused by Ctenocephalides spp. for one month following a single administration. This is as a result of the adulticidal, larvicidal and ovicidal properties of the product. The product is ovicidal for 3 weeks after administration. Through a reduction in the flea population, monthly treatment of pregnant and lactating animals will also aid in the prevention of flea infestations in the litter up to seven weeks of age. The product can be used as part of a treatment strategy for flea allergy dermatitis and through its ovicidal and larvicidal action may aid in the control of existing environmental flea infestations in areas to which the animal has access. Prevention of heartworm disease caused by Dirofilaria immitis with monthly administration. Stronghold may be safely administered to animals infected with adult heartworms, however, it is recommended, in accordance with good veterinary practice, that all animals 6 months of age or more living in countries where a vector exists should be tested for existing adult heartworm infections before beginning medication with Stronghold. It is also recommended that dogs should be tested periodically for adult heartworm infections, as an integral part of a heartworm prevention strategy, even when Stronghold has been administered monthly. This product is not effective against adult D. immitis. Treatment of ear mites (Otodectes cynotis). Cats: Treatment of biting lice infestations (Felicola subrostratusTreatment of adult roundworms (Toxocara cati)Treatment of adult intestinal hookworms (Ancylostoma tubaeforme). Dogs: Treatment of biting lice infestations (Trichodectes canis)Treatment of sarcoptic mange (caused by Sarcoptes scabiei)Treatment of adult intestinal roundworms (Toxocara canis).

C43H63NO11

769.96000

769.44

220119-17-5

220119-17-5

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

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)

DMSO : ≥ 100 mg/mL (~129.88 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (3.25 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: 2.5 mg/mL (3.25 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
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.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (3.25 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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