Antimalaria; Plasmodium falciparum malaria

In vitro tests were conducted to evaluate the antimalarial efficacy of Artemotil against both chloroquine-susceptible and chloroquine-resistant Plasmodium falciparum parasites. Artemotil's 50% inhibitory concentration (IC50) ranges from 1.57 to 1.92 nM on average. Compared to artemisinin, artemotil is about 2.5 times as efficacious [1].

In addition to causing significant reductions in food consumption and body weight after day 2, the administration of 25 mg/kg of artemotil intravenously (i.v.) for seven days to male Sprague-Dawley rats demonstrated anorexigenic toxicity. The AUC on day 7 was five times higher than the AUC on day 1, and the elimination t1/2 of artemotil was also extended from 13.7 hours (day 1) to 31.2 hours (day 7) [2].

The antimalarial activity of beta-artemether and beta-arteether was compared in three test systems: in vitro against chloroquine-resistant and chloroquine-sensitive Plasmodium falciparum parasites, in mice infected with P. berghei, and in Aotus monkeys infected with chloroquine-resistant P. falciparum. In vitro, the mean 50% inhibitory concentration (IC50) for beta-artemether was 1.74 nM (range 1.34-1.81 nM), and this value for beta-arteether was 1.61 nM (range 1.57-1.92 nM). They were approximately 2.5-fold more potent than artemisinin, which had a mean IC50 of 4.11 nM (range 3.36-4.60 nM)[1].

Animal/Disease Models: SD (SD (Sprague-Dawley)) male rats (220-280g) [2]
Doses: 25 mg/kg; 1 mL/kg body weight
Route of Administration: intravenous (iv) (iv)injection; daily; continued for 7 days
Experimental Results: Anorexigenic toxicity was observed, leading to the first Food consumption and body weight were Dramatically diminished after 2 days.

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In the mouse model, the 50% curative doses (CD50) of beta-artemether and beta-arteether had a mean value of 55 mg/kg (32-78 mg/kg). The 50% effective curative doses (ED50) in the Aotus monkey were 7.1 mg/kg (95% confidence interval [CI] = 3.7-13.5) for beta-artemether and 11.8 mg/kg (95% CI = 6.5-21.3) for beta-arteether. Overall, the activities of the two drugs were comparable.[1]

Multiple doses of arteether (ARTE) at 25 mg/kg cause CNS and anorectic toxicities in rats. The same dose of ARTE was used to study the toxicokinetics (TK) after multiple injections and the pharmacokinetics (PK) following single administration. Animals were administered ARTE in sesame oil for 7 days, blood samples were collected using destructive sampling for up to 192 h after dosing and assayed by HPLC-ECD. Two other groups of rats were administered either a single 25 mg/kg i.v. or i.m. dose. In addition, the drug remaining in the i.m. injection site was measured. During the 7 day treatments, anorectic toxicity of ARTE was observed, and that caused significant reductions in food consumption and body weight after day 2. TK data on days 2-7 revealed marked changes compared to the PK parameters estimated on day 1. AUC (4367 ng x h/ml) on day 7 was 5-fold higher than AUC (905 ng x h/ml) on day 1. The volume of distribution at steady state (V(SS)) on day 7 (41.8 l) was 40% of the day 1 value of the V(SS) (104.3 l). Clearance (CL) was increased by 89% of the day 1 value, from 0.98 l/h to 1.85 l/h on day 7. The elimination t(1/2) of ARTE was also prolonged from 13.7 h (day 1) to 31.2 h (day 7). These data suggest that ARTE may have altered its distribution and elimination in rats as a result of the systemic toxicity. Analysis of the injection sites showed that 38% and 91% of the total amount of ARTE single dose remained in the muscles at 24 h (after first injection) and 168 h (at 24 h after 7 daily multiple doses), respectively. Fast and slow absorption phases from muscle were seen with t(1/2) of 0.97 h and 26.3 h, respectively. The apparent elimination t(1/2) of ARTE after i.m. injection (13.7 h) was much longer than that after i.v. dosing (0.67 h) due to the prolonged muscle absorption phase. Acute toxicity data of artemisinin drugs demonstrated that animals receiving a high single ARTE dose in sesame oil died between days 5-11, similar to artemether. When animals received dihydroartemisinin formulated in 50% DMAC/oil, or artesunic acid and artelinic acid in 0.9% saline vehicle, they died between days 1 and 2. This suggests that delayed onset toxicity and death in the ARTE rats may also be due to slow absorption and prolonged drug exposure. Therefore multiple i.m. administrations cause anorexia and drug accumulation, possibly affecting the toxicokinetics and efficacy of the drug.[2]

[1]. Comparison of beta-artemether and beta-arteether against malaria parasites in vitro and in vivo. Am J Trop Med Hyg. 1993 Mar;48(3):377-84.

[2]. Arteether toxicokinetics and pharmacokinetics in rats after 25 mg/kg/day single and multiple doses. Eur J Drug Metab Pharmacokinet. 1999 Jul-Sep;24(3):213-23.

Artemotil is an artemisinin derivative.
Artemotil, also known as β-arteether, is a semi-synthetic derivative of artemisinin and a fast acting blood schizonticide specifically indicated for the treatment of chloroquine-resistant Plasmodium falciparum malaria and cerebral malaria cases.

312.193

C, 65.36; H, 9.03; O, 25.61

75887-54-6

75887-54-6; 109716-83-8;

3000469

White to off-white solid powder

1.2±0.1 g/cm3

372.4±42.0 °C at 760 mmHg

80-820ºC

146.0±27.8 °C

0.0±0.8 mmHg at 25°C

1.516

3.6

0

5

2

22

443

8

O1[C@@]23[C@]4([H])O[C@@]([H])([C@]([H])(C([H])([H])[H])[C@]2([H])C([H])([H])C([H])([H])[C@@]([H])(C([H])([H])[H])[C@]3([H])C([H])([H])C([H])([H])C(C([H])([H])[H])(O1)O4)OC([H])([H])C([H])([H])[H]

NLYNIRQVMRLPIQ-XQLAAWPRSA-N

InChI=1S/C17H28O5/c1-5-18-14-11(3)13-7-6-10(2)12-8-9-16(4)20-15(19-14)17(12,13)22-21-16/h10-15H,5-9H2,1-4H3/t10-,11-,12+,13+,14+,15-,16-,17-/m1/s1

(1R,4S,5R,8S,9R,10S,12R,13R)-10-ethoxy-1,5,9-trimethyl-11,14,15,16-tetraoxatetracyclo[10.3.1.04,13.08,13]hexadecane

Arteether; Arteether; Artemotil; 75887-54-6; Beta-Arteether; SM-227; Artemotilum; .beta.-arteether; Artemotil [INN]; Artemotil Dihydroartemisinin ethyl ether beta-Arteether NSC 665971 SM 227beta-Dihydroartemisinin ethyl ether

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 : ~50 mg/mL (~160.05 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (6.66 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 20.8 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: 2.08 mg/mL (6.66 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 20.8 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: ≥ 2.08 mg/mL (6.66 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 20.8 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.)