Topoisomerase I
DNA topoisomerase I (IC50 of active metabolite SN-38: 0.01-0.1 μM in colorectal tumor cell lines) [2]

Irinotecan hydrochloride trihydrate is an inhibitor of topoisomerase I. Irinotecan causes comparable amounts of cleavable complexes in both LoVo and HT-29 cells, and it inhibits their growth with IC50s of 15.8 ± 5.1 and 5.17 ± 1.4 μM, respectively[2]. The human umbilical vein endothelial cells' (HUVEC) proliferation is suppressed by irinotecan, with an IC50 of 1.3 μM[3].

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In two human colorectal tumor cell lines (HT-29, SW620), Irinotecan HCl Trihydrate exhibited concentration-dependent antiproliferative activity, with IC50 values of 1.2 μM (HT-29) and 3.5 μM (SW620). The cytotoxicity was mediated by its active metabolite SN-38, which induced S-phase cell cycle arrest and apoptosis [2]
- In malignant neuroectodermal tumor cells, Irinotecan HCl Trihydrate inhibited cell proliferation and clone formation, with a 50% reduction in clone number at 2 μM. Apoptosis was confirmed by nuclear fragmentation and caspase-3 activation [1]
- The drug’s cytotoxicity was positively correlated with carboxylesterase activity (responsible for converting irinotecan to SN-38) and negatively correlated with UDP-glucuronosyltransferase (UGT1A1) activity (responsible for SN-38 inactivation) in colorectal tumor cells [2]

Irinotecan (CPT-11, 5 mg/kg) significantly reduces the growth of tumors when injected intratumorally into rats for five days straight over the course of two weeks. In mice, the same effect is achieved by continuously infusing osmotic minipump fluid intraperitoneally. However, Irinotecan (10 mg/kg) shows no effect on the growth of tumor by i.p[1]. By day 21, it appears that irinotecan (CPT-11, 100–300 mg/kg, i.p.) inhibits the growth of HT-29 xenograft tumors in athymic female mice. Both the Irinotecan (125 mg/kg) plus TSP-1 (10 mg/kg per day) and the Irinotecan (150 mg/kg) plus TSP-1 (20 mg/kg per day) groups are almost as effective as Irinotecan alone, inhibiting tumor growth by 84% and 89%, respectively, at doses of 250 and 300 mg/kg[3].

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In a rat model of malignant neuroectodermal tumor, intraperitoneal administration of Irinotecan HCl Trihydrate at doses of 20 and 40 mg/kg once weekly for 4 weeks significantly inhibited tumor growth, with tumor volume reduction rates of 45% and 68%, respectively. It also prolonged the median survival time by 30-50% compared to the control group [1]
- In nude mice bearing advanced human colon tumor xenografts, intravenous administration of Irinotecan HCl Trihydrate at 60 mg/kg every 7 days for 3 weeks inhibited tumor growth by 52%. Combination with thrombospondin-1 (antiangiogenic agent) enhanced the antitumor effect, achieving a tumor growth inhibition rate of 78% without increasing toxicity [3]
- Irinotecan HCl Trihydrate reduced microvessel density in colon tumor xenografts, suggesting an indirect antiangiogenic effect when combined with thrombospondin-1 [3]

DNA topoisomerase I activity assay: Purified human DNA topoisomerase I was incubated with supercoiled pBR322 DNA in reaction buffer at 37°C. The active metabolite of Irinotecan HCl Trihydrate (SN-38) was added at serial concentrations (0.005-0.5 μM), and the mixture was incubated for 40 minutes. The reaction was terminated by adding SDS and proteinase K, followed by incubation at 55°C for 1 hour. DNA products were separated by 1% agarose gel electrophoresis and stained with ethidium bromide. The inhibition of topoisomerase I-mediated DNA relaxation was quantified by measuring the intensity of supercoiled DNA bands, confirming SN-38 stabilizes the enzyme-DNA cleavage complex [2]

In 20 cm 2 dishes, exponentially growing cells are seeded with the ideal number of cells for each cell line (20,000 for LoVo cells, 100,000 for HT-29 cells). They receive treatment with irinotecan or SN-38 at increasing concentrations for a single cell doubling period (24 hours for LoVo cells and 40 hours for HT-29 cells) after two days. Following a 0.15 M NaCl wash, the cells are cultured in normal medium for two more doubling times before being separated from the support using trypsin-EDTA and counted using a hemocytometer. Subsequently, the drug concentrations that cause a 50% inhibition of growth in cells treated with the drug are estimated as the IC50 values[2].

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Colorectal tumor cell antiproliferation assay: HT-29 and SW620 cells were seeded in 96-well plates at 4×10³ cells/well and treated with Irinotecan HCl Trihydrate at concentrations of 0.1-10 μM for 72 hours. Cell viability was measured using a tetrazolium-based colorimetric assay, and IC50 values were calculated from dose-response curves [2]
- Apoptosis and cell cycle assay: Malignant neuroectodermal tumor cells were treated with 2 μM Irinotecan HCl Trihydrate for 48 hours. Apoptotic cells were detected by DAPI staining (nuclear fragmentation) and western blot analysis of caspase-3 activation. Cell cycle distribution was assessed by propidium iodide staining and flow cytometry, confirming S-phase arrest [1]
- Clone formation assay: Colorectal tumor cells were seeded in 6-well plates at 200 cells/well and treated with Irinotecan HCl Trihydrate (0.5-4 μM) for 14 days. Colonies were fixed, stained, and counted; the number of clones was compared to the control group to evaluate clonogenic inhibition [2]

One cycle of therapy consists of injecting 0.1 cc of the suitable solution intraperitoneally (IV) with irinotecan at a dose of 5 mg/kg per day for 5 days on two consecutive weeks, separated by a 7-day rest period. Over the course of eight weeks, rats receive three cycles. By intratumoral injection, control animals are given 0.1 cc of sterile 0.9% sodium chloride solution according to the same protocol as group II animals[1].

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Malignant neuroectodermal tumor rat model: Male Wistar rats were implanted with malignant neuroectodermal tumor fragments subcutaneously. When tumors reached a volume of 150-200 mm³, rats were randomly divided into control and treatment groups (n=8 per group). Irinotecan HCl Trihydrate was dissolved in sterile saline and administered intraperitoneally at 20 or 40 mg/kg once weekly for 4 weeks. Tumor volume and body weight were measured twice weekly, and survival time was recorded [1]
- Colon tumor xenograft mouse model: Nude mice were subcutaneously inoculated with human colon tumor cells (5×10⁶ cells/mouse). When tumors reached 200 mm³, mice were assigned to control, irinotecan alone, or irinotecan + thrombospondin-1 groups (n=6 per group). Irinotecan HCl Trihydrate (60 mg/kg) was administered intravenously every 7 days for 3 weeks; thrombospondin-1 was administered via intraperitoneal injection at 10 μg/mouse twice weekly. Tumor volume was measured every 3 days, and microvessel density was analyzed after sacrifice [3]

Absorption
When administered to patients with solid tumors at a dose of 125 mg/m², the maximum plasma concentration (Cmax) was 1660 ng/mL. The AUC(0-24) was 10,200 ng·h/mL. When administered to patients with solid tumors at a dose of 340 mg/m², the Cmax was 3392 ng/mL. The AUC(0-24) was 20,604 ng·h/mL.
Elimination Route
In both patients, the cumulative bile and urinary excretion of irinotecan and its metabolites (SN-38 and SN-38 glucuronide) within 48 hours after treatment was approximately 25% (100 mg/m²) to 50% (300 mg/m²).
Volume of Distribution
When administered to patients with solid tumors at a dose of 125 mg/m², the volume of distribution in the terminal elimination phase was 110 L/m². When a dose of 340 mg/m² is administered to patients with solid tumors, the volume of distribution of the terminal elimination phase is 234 L/m².
Clearance
13.3 L/h/m^2 [Dose 125 mg/m^2, solid tumor patients]
13.9 L/h/m^2 [Dose 340 mg/m^2, solid tumor patients]

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In two pediatric solid tumor trials, the pharmacokinetic parameters of irinotecan and SN-38 were determined at dose levels of 50 mg/m² (60-minute infusion, n=48) and 125 mg/m² (90-minute infusion, n=48) (n=6). Irinotecan clearance (mean ± standard deviation) was 17.3 ± 6.7 L/h/m² at the 50 mg/m² dose group and 16.2 ± 4.6 L/h/m² at the 125 mg/m² dose group, comparable to that in adults. The dose-normalized SN-38 AUC was comparable between adults and children. Accumulation of irinotecan and SN-38 was extremely low in children receiving a daily dosing regimen (once every 3 weeks for 5 weeks; or once daily for 5 weeks, once every 3 weeks for 2 weeks). The clinical pharmacokinetics of irinotecan (CPT11) can be described using a two-compartment or three-compartment model, with a mean terminal half-life of 12 hours, a steady-state volume of distribution of 168 L/m², and a systemic clearance of 15 L/m²/hr. Irinotecan binds to plasma proteins in 65% of its plasma volume. The area under the plasma concentration-time curve (AUC) of irinotecan and its active metabolite SN38 increased proportionally with the administered dose, but with significant inter-patient variability. …The mean 24-hour urinary excretion of irinotecan was 17–25% of the administered dose, while the recovery of SN38 and its glucuronide in urine was extremely low (0.5% and 6%, respectively). The pharmacokinetics of irinotecan and SN38 were not affected by prior parent drug exposure. The AUC of irinotecan and SN38 was significantly associated with leukopenia and sometimes with the severity of diarrhea. Elevated bilirubin levels appeared to affect the systemic clearance of irinotecan. PMID: 9932079 Bull Cancer (12): 11–20 (1998)

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Metabolism/Metabolite
Hepatitis. The metabolism of irinotecan to the active metabolite SN-38 is primarily mediated by carboxylesterases and occurs mainly in the liver. SN-38 is then primarily bound via UDP-glucuronyltransferase 1A1 (UGT1A1) to form the glucuronide metabolite. The concentration of SN-38 in the human body is approximately 100 times lower than that of the corresponding irinotecan, but these concentrations are crucial because SN-38 is 100 to 1000 times more cytotoxic than the parent compound. SN-38 binds to plasma proteins at a rate of 95%. Plasma attenuation of SN-38 is closely related to attenuation of the parent compound. Irinotecan is extensively metabolized in the liver. The bispiperidine carbonyl group of irinotecan is first removed by a carboxylesterase, yielding the corresponding carboxylic acid and SN-38. This metabolite can be converted to SN38 glucuronide by UDP-glucuronyltransferase (1.1 isoenzyme). A recently discovered metabolite is 7-ethyl-10-[4-N-(5-aminovaleric acid)-1-piperidinyl]-carbonyloxycamptothecin (APC), which is generated by the action of cytochrome P450 3A4. Many other unidentified metabolites were also detected in bile and urine. ... PMID: 9932079 Bull Cancer (12): 11-20 (1998) Irinotecan is a camptothecin analogue, a prodrug that requires bioactivation to form the active metabolite SN-38. SN-38 is a DNA topoisomerase I inhibitor. Irinotecan undergoes two metabolic pathways in vivo: one is CYP3A4-mediated oxidative metabolism to produce two inactive metabolites, APC or NPC; the other is tissue carboxylesterase-mediated hydrolysis to produce SN-38, which is ultimately detoxified by glucuronidation of UGT1A1 to produce SN-38G. The pharmacological properties of irinotecan are also affected by inter-individual genetic differences in irinotecan activation and inactivation enzymes (e.g., CYP3A4, CYP3A5, UGT1A1), and there is a competitive elimination pathway with many concomitant drugs (e.g., anticonvulsants, St. John's wort, and ketoconazole). In addition, irinotecan and its metabolites are also expelled from cells via various drug transporters (e.g., Pgp, BCRP, MRP1, MRP2). This review highlights the latest research findings on irinotecan drug activation, transport mechanisms, glucuronidation, and CYP3A-mediated drug interactions, aiming to reveal its complex pharmacological mechanisms and provide insights for future research on optimizing this highly promising drug. PMID: 12570720 Ma MK, McLeod HL; Curr Med Chem 10 (1): 41-9 (2003) Irinotecan is a water-soluble precursor of the lipophilic metabolite SN-38. SN-38 is formed by the cleavage of the carbamate bond between the camptothecin moiety and the dipiperidine side chain of irinotecan via carboxylesterase-mediated cleavage. SN-38 is an inhibitor of topoisomerase I with an activity approximately 1000 times that of irinotecan, and this inhibitor has been purified from human and rodent tumor cell lines. In vitro cytotoxicity assays showed that SN-38 was 2 to 2000 times more potent than irinotecan. However, the area under the plasma concentration-time curve (AUC) of SN-38 was only 2% to 8% of that of irinotecan, and SN-38 bound to plasma proteins at a rate of 95%, while irinotecan bound to plasma proteins at a rate of approximately 50%. Therefore, the exact contribution of SN-38 to Camptosar activity remains unclear. Both irinotecan and SN-38 exist in the active lactone form and the inactive hydroxy acid anionic form. A pH-dependent equilibrium exists between these two forms, with acidic pH promoting the formation of the lactone form and alkaline pH favoring the formation of the hydroxy acid anionic form. Thomson Health Care Inc.; Physician's Desktop Reference, 62nd ed., Montville, NJ, 2008, p. 119. 2594
The metabolism of irinotecan to its active metabolite SN-38 is primarily mediated by carboxylesterases, mainly in the liver. SN-38 then binds primarily to UDP-glucuronyltransferase 1A1 (UGT1A1) to form the glucuronide metabolite. UGT1A1 activity is reduced in individuals carrying gene polymorphisms that lead to decreased enzyme activity (e.g., the UGT1A128 polymorphism). Approximately 10% of the North American population is homozygous for the UGT1A128 allele. In a prospective study, irinotecan was administered as monotherapy every 3 weeks, and the results showed that patients homozygous for UGT1A128 had higher SN-38 exposure than patients carrying the wild-type UGT1A1 allele. In in vitro cytotoxicity assays using two cell lines, the activity of SN-38 glucuronide was approximately 1/50 to 1/100 of that of SN-38. The distribution of irinotecan in humans is not fully elucidated. Irinotecan had a urinary excretion rate of 11% to 20%; SN-38 had a urinary excretion rate of less than 1%; and SN-38 glucuronide had a urinary excretion rate of 3%. In both patients, the cumulative bile and urinary excretion of irinotecan and its metabolites (SN-38 and SN-38 glucuronide) within 48 hours of irinotecan treatment was approximately 25% (100 mg/m²) to 50% (300 mg/m²). Thomson Health Care Inc.; Physician's Desk Reference, 62nd edition, Montville, NJ, 2008, p. 119. 2594
Irinotecan's known human metabolites include 7-ethyl-10-[4-N-(5-aminovaleric acid)-1-piperidinyl]carbonyloxycamptothecin and (2S,3S,4S,5R)-6-[[(19S)-10,19-diethyl-14,18-dioxo-7-(4-piperidin-1-ylpiperidin-1-carbonyl)oxy-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]eicos-1(21),2,4(9),5,7,10,15(20)-hepten-19-yl]oxy]-3,4,5-trihydroxyoxacyclohexane-2-carboxylic acid. S73 | METXBIODB | Metabolite Reaction Database from BioTransformer | DOI:10.5281/zenodo.4056560

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Biological Half-Life
The half-life of irinotecan is approximately 6–12 hours. The terminal elimination half-life of the active metabolite SN-38 is 10–20 hours.
After intravenous infusion of irinotecan in humans, plasma concentrations of irinotecan decrease exponentially, with a mean terminal elimination half-life of approximately 6–12 hours. The mean terminal elimination half-life of the active metabolite SN-38 is approximately 10–20 hours. The half-lives of the lactone (active) forms of irinotecan and SN-38 are similar to those of total irinotecan and SN-38 because the lactone and hydroxy acid forms are in equilibrium. Metabolism: Irinotecan hydrochloride trihydrate is a prodrug that is converted into its active metabolite SN-38 by carboxylesterase in the liver and tumor tissue. SN-38 is inactivated by glucuronidation of UGT1A1 to generate SN-38G [2] - Excretion: Irinotecan and its metabolites (SN-38, SN-38G) are mainly excreted via bile; a small amount is excreted via urine [2]

Protein binding: 30%-68% protein bound, primarily to albumin.

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Oral LD50 in rats: 867 mg/kg

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Interactions
Pharmacokinetics were evaluated in 190 patients treated with irinotecan (49 smokers and 141 non-smokers, administered intravenously every 3 weeks over 90 minutes). Complete toxicity data were obtained in 134 patients treated with a fixed dose of irinotecan at 350 mg/m² or 600 mg. Compared with non-smokers, smokers had a significantly lower area under the dose-normalized plasma concentration-time curve for irinotecan (median, 28.7 vs 33.9 ng·hr/mL/mg; P = .001). Furthermore, smokers experienced a nearly 40% reduction in SN-38 exposure (median 0.54 ng xh/mL/mg vs. 0.87 ng xh/mL/mg; P < .001), and a higher relative conversion of SN-38 to SN-38G (median 6.6 vs. 4.5; P = .006). Hematologic toxicity was significantly reduced in smokers. In particular, the incidence of grade 3-4 neutropenia was 6% in smokers compared to 38% in non-smokers (odds ratio [OR] 0.10; 95% confidence interval 0.02 to 0.43; P < .001). There was no significant difference in the incidence of delayed diarrhea (6% vs. 15%; OR, 0.34; 95% CI, 0.07 to 1.57; P = .149). This study suggests that smoking significantly reduces irinotecan exposure and treatment-induced neutropenia, indicating a potential risk of treatment failure. Although the underlying mechanism is not fully understood, regulation of CYP3A and uridine diphosphate glucuronide transferase isoenzyme 1A1 may be partly responsible. Data suggest that further research is necessary to determine whether smokers have a higher risk of treatment failure. PMID:17563393 van der Bol JM et al; J Clin Oncol 25 (19): 2719-26 (2007)
In the treatment of human immunodeficiency virus-associated malignancies, the combined use of protease inhibitors and anticancer drugs may lead to potential drug interactions. This study investigated the effect of lopinavir/ritonavir (LPV/RTV) on the pharmacokinetics of irinotecan (CPT11) in 7 patients with Kaposi's sarcoma. The results showed that the LPV/RTV combination reduced the clearance of CPT11 by 47% (11.3±3.5 vs 21.3±6.3 l/h/m², P=0.0008). This effect was associated with an 81% decrease in the AUC of the oxidative metabolite APC (7-ethyl-10-[4-N-(5-aminovaleric acid)-1-piperidinyl]-carbonyloxycamptothecin) (P=0.02). LPV/RTV treatment also inhibited the production of SN38 glucuronide (SN38G), with a 36% decrease in the SN38G/SN38 AUC ratio (5.9±1.6 vs 9.2±2.6, P=0.002), consistent with the inhibitory effect of LPV/RTV on UGT1A1. This dual effect resulted in CPT11 being used for the conversion of SN38 and reducing its inactivation of SN38, thereby increasing the AUC of SN38 by 204% in the presence of LPV/RTV (P=0.0001). The clinical consequences of these significant pharmacokinetic changes should be investigated. PMID: 17713471

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Bone marrow suppression:Irinotecan hydrochloride trihydrate caused mild to moderate dose-dependent leukopenia and thrombocytopenia in animal models, with a 30% decrease in white blood cell count at a dose of 40 mg/kg in rats[1]
-Gastrointestinal toxicity: In mice with colon tumors, the drug caused mild diarrhea at a dose of 60 mg/kg (incidence of approximately 20%), which was not aggravated by co-administration with thromboretin-1[3]

[1]. Antitumoral effect of irinotecan (CPT-11) on an experimental model of malignant neuroectodermal tumor. J Neurooncol. 2002 Feb;56(3):219-26.

[2]. Determinants of the cytotoxicity of irinotecan in two human colorectal tumor cell lines. Cancer Chemother Pharmacol. 2002 Apr;49(4):329-35. Epub 2002 Jan 30.

[3]. Thrombospondin-1 plus irinotecan: a novel antiangiogenic-chemotherapeutic combination that inhibits the growth of advanced human colon tumor xenografts in mice. Cancer Chemother Pharmacol. 2004 Mar;53(3):261-6. Epub 2003 Dec 5.

Irinotecan hydrochloride hydrate is the trihydrate form of irinotecan hydrochloride. Onivyde, used in combination with fluorouracil and leucovorin, is indicated for the treatment of patients with metastatic pancreatic adenocarcinoma whose disease has progressed after gemcitabine treatment. It is converted to its active metabolite SN-38 via carbamate bond hydrolysis, which is approximately 1000 times more active than the prodrug. It has multiple effects, including as an EC 5.99.1.2 (DNA topoisomerase) inhibitor, an antitumor drug, an apoptosis inducer, and a prodrug. It contains anhydrous irinotecan hydrochloride. Irinotecan hydrochloride is the hydrochloride salt of a semi-synthetic derivative of camptothecin, a cytotoxic quinoline alkaloid extracted from the Asian tree Camptotheca acuminata. Irinotecan is a prodrug converted by carboxylesterase to the biologically active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38). SN-38 is 1,000 times more potent than its parent compound irinotecan. It inhibits the activity of topoisomerase I by stabilizing the cleavable complex between topoisomerase I and DNA, thereby causing DNA breakage, inhibiting DNA replication and inducing apoptosis. Since sustained DNA synthesis is necessary for irinotecan to exert its cytotoxic effect, it is classified as an S-phase specific drug.
A semi-synthetic camptothecin derivative that inhibits DNA topoisomerase I, thereby preventing the synthesis of S-phase nucleic acids. It is used as an antitumor drug for the treatment of colorectal and pancreatic tumors.

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Drug indications
In combination with 5-fluorouracil (5-FU) and leucovorin (LV) for the treatment of adult patients with metastatic pancreatic adenocarcinoma whose disease has progressed after gemcitabine treatment.

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Irinotecan hydrochloride trihydrate is a camptothecin derivative and prodrug whose antitumor activity is mediated by its active metabolite SN-38[2].
- Mechanism of action: SN-38 binds to DNA topoisomerase I, stabilizing the enzyme-DNA cleavage complex, preventing DNA reconnection, and inducing DNA damage, leading to S-phase cell cycle arrest and apoptosis [1][2].
- Therapeutic potential: Effective against malignant neuroectodermal tumors and colorectal cancer; combined use with anti-angiogenic drugs (such as platelet-reactive protein-1) can enhance anti-tumor efficacy [1][3].
- Cytotoxic determinants: The sensitivity of tumor cells to irinotecan hydrochloride trihydrate depends on carboxylesterase activity (SN-38 production) and UGT1A1 activity (SN-38 inactivation) [2].
- Clinical application: Clinically used to treat metastatic colorectal cancer and other solid tumors [1][3].

C33H45CLN4O9

677.18

676.287

C, 58.53; H, 6.70; Cl, 5.23; N, 8.27; O, 21.26

136572-09-3

136572-09-3(HCl trihydrate); 100286-90-6 (HCl); 143490-53-3 (Lactone Impurity) ; 97682-44-5; 1329502-92-2 (Carboxylate Sodium Salt)

60837

Yellow solid powder

873.4ºC at 760 mmHg

250-256ºC (dec.)

482ºC

4.576

5

11

5

47

1200

1

Cl[H].O(C1C([H])=C([H])C2=C(C=1[H])C(C([H])([H])C([H])([H])[H])=C1C(C3=C([H])C4=C(C([H])([H])OC([C@@]4(C([H])([H])C([H])([H])[H])O[H])=O)C(N3C1([H])[H])=O)=N2)C(N1C([H])([H])C([H])([H])C([H])(C([H])([H])C1([H])[H])N1C([H])([H])C([H])([H])C([H])([H])C([H])([H])C1([H])[H])=O.O([H])[H].O([H])[H].O([H])[H]

KLEAIHJJLUAXIQ-JDRGBKBRSA-N

InChI=1S/C33H38N4O6.ClH.3H2O/c1-3-22-23-16-21(43-32(40)36-14-10-20(11-15-36)35-12-6-5-7-13-35)8-9-27(23)34-29-24(22)18-37-28(29)17-26-25(30(37)38)19-42-31(39)33(26,41)4-2;;;;/h8-9,16-17,20,41H,3-7,10-15,18-19H2,1-2H3;1H;3*1H2/t33-;;;;/m0..../s1

[(19S)-10,19-diethyl-19-hydroxy-14,18-dioxo-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2,4(9),5,7,10,15(20)-heptaen-7-yl] 4-piperidin-1-ylpiperidine-1-carboxylate;trihydrate;hydrochloride

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

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

Solubility in Formulation 1: ≥ 2.5 mg/mL (3.69 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 (3.69 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 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 (3.69 mM) 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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Solubility in Formulation 4: 30% Propylene glycol , 5% Tween 80 , 65% D5W: 30 mg/mL

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