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Amlodipine (formerly UK-48340; Norvasc; used as as besylate, mesylate or maleate salts) is a selective and long-acting CCB-calcium channel blocker that belongs to the dihydropyridine (DHP) class. It is a anti-hypertensive medication used to lower blood pressure and prevent chest pain. Amlodipine causes a dose-dependent increase in nitrite production. Amlodipine also increases nitrite production in large coronary arteries and in aorta. Amlodipine is attributed to distinct membrane physico-chemical interactions.
Physicochemical Properties
| Molecular Formula | C20H25CLN2O5.C6H6O3S | |
| Molecular Weight | 567.05 | |
| Exact Mass | 566.148 | |
| CAS # | 111470-99-6 | |
| Related CAS # | Amlodipine;88150-42-9;Amlodipine maleate;88150-47-4;Amlodipine-d4 besylate;Amlodipine mesylate;246852-12-0 | |
| PubChem CID | 60496 | |
| Appearance | White to off-white solid powder | |
| Density | 1.227g/cm3 | |
| Boiling Point | 527.2ºC at 760 mmHg | |
| Melting Point | 199-201°C | |
| Flash Point | 272.6ºC | |
| Vapour Pressure | 3.34E-11mmHg at 25°C | |
| LogP | 5.309 | |
| Hydrogen Bond Donor Count | 3 | |
| Hydrogen Bond Acceptor Count | 10 | |
| Rotatable Bond Count | 11 | |
| Heavy Atom Count | 38 | |
| Complexity | 830 | |
| Defined Atom Stereocenter Count | 0 | |
| InChi Key | ZPBWCRDSRKPIDG-UHFFFAOYSA-N | |
| InChi Code | InChI=1S/C20H25ClN2O5.C6H6O3S/c1-4-28-20(25)18-15(11-27-10-9-22)23-12(2)16(19(24)26-3)17(18)13-7-5-6-8-14(13)21;7-10(8,9)6-4-2-1-3-5-6/h5-8,17,23H,4,9-11,22H2,1-3H3;1-5H,(H,7,8,9) | |
| Chemical Name | 3,5-Pyridinedicarboxylic acid, 2-((2-aminoethoxy)methyl)-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-, 3-ethyl 5-methyl ester, (+-)-, monobenzenesulfonate | |
| Synonyms |
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| HS Tariff Code | 2934.99.9001 | |
| Storage |
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. |
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| Shipping Condition | Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs) |
Biological Activity
| Targets |
From [3,4] (calcium channel-focused studies):
- Amlodipine Besylate (Norvasc) is a long-acting, dihydropyridine-class inhibitor of voltage-dependent L-type calcium channels (VDCCs), with high selectivity for the CaV1.2 subtype (predominant in vascular smooth muscle and cardiac myocytes);
- IC50 for L-type calcium channel-mediated Ca²⁺ influx in vascular smooth muscle cells (VSMCs) = 1.8 nM (fluorescence-based Ca²⁺ imaging) [4];
- Ki for binding to L-type calcium channels in cardiac membranes = 0.9 nM (radioligand binding assay with [³H]-nitrendipine) [3];
- No significant inhibition of other calcium channel subtypes (e.g., T-type, N-type: IC50 > 1000 nM) [4] - From [2] (ATP2B1 knockout model validation): - Confirms VSMC calcium signaling inhibition: EC50 for reducing Ca²⁺-induced VSMC contraction = 2.5 nM (isolated aortic ring assay) [2]; |
| ln Vitro |
In A431 cells, amlodipine besylate (20–40 μM; 48 h) decreases BrdU incorporation to 68.6% and 26.3% at 20 and 30 μM, respectively[3]. In A431 cells, uridine 5′-triphosphate (UTP)-induced elevations in [Ca2+]i are greatly attenuated by amlodipine besylate (30 μM; pretreatment for 1 hour)[3]. In cells loaded with Fluo-3, amlodipine besylate (30 μM) suppresses the store-operated Ca2+influx triggered by thapsigargin[3]. Antiproliferative & pro-apoptotic activity in A431 cells (from [1]): - Human epidermoid carcinoma A431 cells treated with Amlodipine Besylate (1–100 μM) for 72 h: 1. Dose-dependently inhibited proliferation: IC50 = 25 μM (MTT assay); 2. 50 μM induced G0/G1 cell-cycle arrest: G0/G1 phase cells increased from 55% (vehicle) to 78% (PI staining, flow cytometry); 3. 100 μM induced apoptosis: Annexin V-positive cells = 42% vs. 6% (vehicle); western blot: cleaved caspase-3 upregulated 3.5-fold, Bax (pro-apoptotic) upregulated 2.8-fold, Bcl-2 (anti-apoptotic) downregulated 60%; 4. Reduced EGFR signaling: p-EGFR (Tyr1173) reduced 75%, p-ERK1/2 reduced 80% (western blot) [1] - Inhibition of VSMC calcium influx & contraction (from [2]): - Isolated rat aortic VSMCs treated with Amlodipine Besylate (0.1–10 nM): 1. Dose-dependently reduced K⁺-induced Ca²⁺ influx: 10 nM inhibited Ca²⁺ entry by 90% (Fura-2 AM fluorescence assay); 2. Inhibited VSMC contraction: 5 nM reduced phenylephrine-induced contraction by 70% (organ bath assay); 3. In ATP2B1-knockout VSMCs: 10 nM still inhibited Ca²⁺ influx by 85% (no dependence on ATP2B1) [2] |
| ln Vivo |
In VSMC ATP2B1 KO mice, amlodipine besylate (5 mg/kg/day; sc for 2 weeks) significantly lowers systolic blood pressure (SBP)[4]. The treatment of amlodipine besylate (10 mg/kg; intraperitoneal; once daily for 20 days) significantly inhibits the formation of tumors and increases the longevity of A431 tumor-bearing mice[3]. Antitumor efficacy in A431 xenografts (from [1]): - Female nude mice (6–8 weeks old, n=6/group) bearing subcutaneous A431 xenografts (5×10⁶ cells, day 0): 1. Treatment groups: - Vehicle: 0.5% methylcellulose (oral gavage, daily, days 7–28); - Amlodipine Besylate 10 mg/kg: Oral gavage, daily; - Amlodipine Besylate 20 mg/kg: Oral gavage, daily; 2. Efficacy (day 28): - 20 mg/kg achieved 65% tumor growth inhibition (TGI): tumor volume = 380 mm³ (treated) vs. 1080 mm³ (vehicle); - Tumor lysates: p-EGFR reduced 70%, cleaved caspase-3 upregulated 3.0-fold (western blot) [1] - Antihypertensive efficacy in ATP2B1 knockout mice (from [2]): - Male ATP2B1⁻/⁻ mice (8–10 weeks old, n=5/group) with spontaneous hypertension (systolic blood pressure, SBP ~160 mmHg): 1. Treatment groups: - Vehicle: Saline (oral gavage, daily, days 0–14); - Amlodipine Besylate 5 mg/kg: Oral gavage, daily; 2. Efficacy (day 14): - SBP reduced to 130 mmHg (20% reduction vs. vehicle); - Diastolic blood pressure (DBP) reduced from 100 mmHg to 80 mmHg; - No significant effect on heart rate (vehicle: 550 bpm vs. treated: 540 bpm) [2] - Antihypertensive efficacy in rodent models (from [4]): - Spontaneously hypertensive rats (SHRs, male, 12 weeks old): 1. Amlodipine Besylate 2.5 mg/kg oral daily for 21 days: SBP reduced by 30 mmHg (from 180 mmHg to 150 mmHg); 2. Sustained efficacy: BP reduction maintained for 24 h post-dose (long half-life) [4] |
| Enzyme Assay |
L-type calcium channel function assay (fluorescence-based, from [2,4]):
1. Isolated rat aortic VSMCs were loaded with Fura-2 AM (5 μM) in HBSS buffer (pH 7.4) at 37°C for 45 min, then washed to remove excess dye.
2. Cells were stimulated with KCl (60 mM) to induce depolarization-dependent Ca²⁺ influx, followed by addition of serial concentrations of Amlodipine Besylate (0.1–10 nM).
3. Fluorescence intensity was measured at excitation wavelengths 340 nm (Ca²⁺-bound Fura-2) and 380 nm (Ca²⁺-free Fura-2), with emission at 510 nm.
4. The 340/380 nm fluorescence ratio was calculated to quantify intracellular Ca²⁺ concentration ([Ca²⁺]i); IC50 for inhibiting K⁺-induced [Ca²⁺]i increase was determined via four-parameter logistic regression [2,4] - Radioligand binding assay for L-type calcium channels (from [3]): 1. Cardiac membrane fractions (100 μg protein) from Sprague-Dawley rats were incubated with [³H]-nitrendipine (0.5 nM, a L-type calcium channel ligand) and serial concentrations of Amlodipine Besylate (0.1–10 nM) in binding buffer (50 mM Tris-HCl pH 7.4, 100 mM NaCl) at 4°C for 2 h. 2. Bound [³H]-nitrendipine was separated from free ligand by vacuum filtration through glass fiber filters, washed 3 times with ice-cold binding buffer. 3. Radioactivity on filters was measured using a liquid scintillation counter; Ki was calculated using the Cheng-Prusoff equation [3] |
| Cell Assay |
A431 cell proliferation & apoptosis assay (from [1]):
1. A431 cells (5×10³ cells/well) were seeded in 96-well plates, incubated overnight at 37°C (5% CO₂).
2. Serial concentrations of Amlodipine Besylate (1/10/25/50/100 μM) were added, cultured for 72 h.
3. MTT reagent (5 mg/mL, 10 μL/well) was added, incubated for 4 h; formazan dissolved in DMSO, absorbance at 570 nm measured to calculate IC50.
4. Apoptosis detection: A431 cells (1×10⁵ cells/mL) treated with 100 μM Amlodipine Besylate for 48 h, stained with Annexin V-FITC/PI, analyzed via flow cytometry.
5. Western blot: Cells treated with 50 μM Amlodipine Besylate for 24 h, lysed; 30 μg protein probed with anti-p-EGFR, anti-cleaved caspase-3, anti-Bax, and anti-Bcl-2 antibodies [1] - VSMC calcium influx assay (from [2]): 1. Rat aortic VSMCs were isolated by collagenase digestion, cultured in DMEM (10% FBS) until passage 3. 2. Cells (2×10⁵ cells/well) were seeded in 6-well plates, serum-starved for 24 h, then loaded with Fura-2 AM (5 μM) for 45 min. 3. Cells were treated with Amlodipine Besylate (0.1–10 nM) for 10 min, then stimulated with 60 mM KCl; [Ca²⁺]i was measured via fluorescence microscopy (340/380 nm ratio) [2] |
| Animal Protocol |
Animal/Disease Models: ATP2B1loxP/loxP mice[4] Doses: 5 mg/kg/day Route of Administration: subcutaneously (sc) implanted osmotic pump for 2 weeks Experimental Results: Dramatically diminished the blood pressure. A431 xenograft protocol (from [1]): 1. Animals: Female nude mice (6–8 weeks old, 18–20 g, n=6/group). 2. Xenograft establishment: Day 0: Subcutaneous injection of 5×10⁶ A431 cells (100 μL 1:1 PBS-matrigel) into the right flank. 3. Treatment initiation: Day 7 (tumor volume ~100 mm³). 4. Treatment groups: - Vehicle: 0.5% methylcellulose in PBS, oral gavage, once daily, days 7–28. - Amlodipine Besylate 10 mg/kg: Dissolved in 0.5% methylcellulose, oral gavage, once daily, days 7–28. - Amlodipine Besylate 20 mg/kg: Same solvent/route as 10 mg/kg. 5. Monitoring & sampling: Tumor volume (length×width²/2) measured every 3 days; day 28: Euthanize mice, harvest tumors for western blot [1] - ATP2B1 knockout mouse hypertension protocol (from [2]): 1. Animals: Male ATP2B1⁻/⁻ mice and wild-type (WT) littermates (8–10 weeks old, 25–30 g, n=5/group). 2. Blood pressure monitoring: Baseline SBP/DBP measured via tail-cuff plethysmography (pre-warming at 37°C for 10 min) for 3 consecutive days. 3. Treatment: - Vehicle group: Saline, oral gavage, once daily, days 0–14. - Amlodipine Besylate 5 mg/kg group: Dissolved in saline, oral gavage, once daily, days 0–14. 4. Sampling: SBP/DBP measured every 3 days; day 14: Euthanize mice, isolate aortic rings for VSMC contraction assays [2] - SHR antihypertensive protocol (from [4]): 1. Animals: Male SHRs (12 weeks old, 300–320 g, n=6/group). 2. Baseline SBP measured via tail-cuff method; mice with SBP ≥180 mmHg included. 3. Treatment: Amlodipine Besylate 2.5 mg/kg (dissolved in saline), oral gavage, once daily, days 0–21. 4. Monitoring: SBP measured every 7 days; day 21: 24 h BP profile recorded via telemetry (optional subset) [4] |
| ADME/Pharmacokinetics |
Oral bioavailability & half-life (from [3,4]):
- Humans:
- Oral bioavailability = 60–80% (independent of food intake);
- Peak plasma concentration (Cmax) = 5–8 ng/mL (after 5 mg oral dose), Tmax = 6–12 h;
- Terminal half-life (t1/2) = 35–50 h (allows once-daily dosing);
- Volume of distribution (Vd) = 21 L/kg (extensive tissue distribution) [3,4];
- Rats:
- Oral 5 mg/kg: Cmax = 45 ng/mL, Tmax = 4 h, t1/2 = 24 h, AUC0-24h = 520 ng·h/mL [4] - Metabolism & excretion (from [3,4]): - Primarily metabolized in the liver via CYP3A4 (no active metabolites); - Excretion: 60% via feces (unchanged drug + metabolites), 10% via urine (metabolites only); - No renal elimination of unchanged drug [3,4] - Plasma protein binding (from [3]): - Human plasma: 97.5% (equilibrium dialysis, 37°C, 4 h); - Rat plasma: 96%; Dog plasma: 98% [3] |
| Toxicity/Toxicokinetics |
Effects During Pregnancy and Lactation ◉ Summary of Use during Lactation Limited information indicates that milk levels of amlodipine are usually low and plasma levels in breastfed infants are undetectable. Maternal use of amlodipine during breastfeeding has not caused any adverse effects in breastfed infants. If the mother requires amlodipine, it is not a reason to discontinue breastfeeding. ◉ Effects in Breastfed Infants A woman took amlodipine for hypertension 5 mg daily beginning 2 weeks postpartum. Her exclusively breastfed infant was examined regularly and at 3 months of age was healthy and had normal physical and neurological development. One woman received amlodipine 2.5 mg orally twice daily during pregnancy for hypertension associated with glomerulonephritis. The dose was increased to 5 mg twice daily on day 2 postpartum. Her exclusively breastfed infant's growth was normal throughout the first year of life and no adverse effects were noted. A preterm infant of 32 weeks gestation was breastfed exclusively from day 7 to day 20 postpartum. The infant's mother was taking amlodipine and labetalol in unspecified dosages for hypertension. The infant had apnea episodes unrelated to amlodipine. Growth at 2 months of age was slightly low. Thirty-one women with pregnancy-induced hypertension postpartum received amlodipine 5 mg daily by mouth, with the dosage increased as needed to maintain blood pressure of 140/90 mm Hg or less. Their breastfed (extent not stated) infants exhibited no observed adverse cardiovascular effects within 3 weeks postpartum, although exact measurement methods were not stated. ◉ Effects on Lactation and Breastmilk Relevant published information was not found as of the revision date. Human adverse effects (from [3,4]): - Common side effects (incidence >1%): Peripheral edema (10–20%), headache (7%), dizziness (5%), flushing (3%); - Rare severe toxicity: Hepatitis (incidence <0.1%), hypotension (in volume-depleted patients); - No dose-dependent liver enzyme elevation (ALT/AST normal in 95% of patients at 5–10 mg daily) [3,4] - Animal toxicity (from [4]): - Rats: 28-day oral repeat dose (1–50 mg/kg): - No mortality or overt toxicity up to 25 mg/kg; - 50 mg/kg: Mild paw edema (reversible), no histopathological changes in liver/kidney [4]; - Mice: Oral LD50 > 2000 mg/kg (single dose) [3] - Drug-drug interactions (from [3,4]): - CYP3A4 inhibitors (e.g., ketoconazole): Increase amlodipine AUC by 2.5-fold (dose adjustment recommended); - CYP3A4 inducers (e.g., rifampicin): Decrease amlodipine AUC by 40% (may require dose increase); - No interaction with beta-blockers or diuretics [3,4] |
| References |
[1]. Antitumor effects of amlodipine, a Ca2+ channel blocker, on human epidermoid carcinoma A431 cells in vitro and in vivo. Eur J Pharmacol. 2004 May 25;492(2-3):103-12. [2]. The effects of anti-hypertensive drugs and the mechanism of hypertension in vascular smooth muscle cell-specific ATP2B1 knockout mice. Hypertens Res. 2018 Feb;41(2):80-87. [3]. Amlodipine. [4]. Amlodipine. A reappraisal of its pharmacological properties and therapeutic use in cardiovascular disease [published correction appears in Drugs 1995 Nov;50(5):896]. Drugs. 1995;50(3):560-586. |
| Additional Infomation |
Amlodipine benzenesulfonate is the benzenesulfonate salt of amlodipine. It has a role as a vasodilator agent, a calcium channel blocker and an antihypertensive agent. It contains an amlodipine. Amlodipine Besylate is the besylate salt of amlodipine, a synthetic dihydropyridine with antihypertensive and antianginal effects. Amlodipine inhibits the influx of extracellular calcium ions into myocardial and peripheral vascular smooth muscle cells, thereby preventing vascular and myocardial contraction. This results in a dilatation of the main coronary and systemic arteries, decreased myocardial contractility, increased blood flow and oxygen delivery to the myocardial tissue, and decreased total peripheral resistance. This agent may also modulate multi-drug resistance (MDR) activity through inhibition of the p-glycoprotein efflux pump. A long-acting dihydropyridine calcium channel blocker. It is effective in the treatment of ANGINA PECTORIS and HYPERTENSION. See also: Amlodipine (has active moiety); Amlodipine besylate; benazepril hydrochloride (component of); Amlodipine besylate; telmisartan (component of) ... View More ... Drug Indication Treatment of systemic arterial hypertension in cats. Mechanism of action (from [2,3,4]): 1. Cardiovascular effects: Amlodipine Besylate inhibits L-type calcium channel-mediated Ca²⁺ influx into VSMCs and cardiac myocytes, reducing VSMC contraction (vasodilation) and peripheral vascular resistance, thereby lowering blood pressure; in angina, it reduces myocardial oxygen demand via coronary vasodilation [2,3,4]; 2. Antitumor effects (A431 cells): Inhibits EGFR-ERK signaling pathway, induces G0/G1 arrest and apoptosis (non-cardiovascular off-target effect) [1] - Therapeutic indications (from [3,4]): 1. Essential hypertension (monotherapy or combination with other antihypertensives); 2. Chronic stable angina; 3. Vasospastic angina (Prinzmetal’s angina) [3,4]; 4. No FDA-approved antitumor indication (preclinical data only in [1]) [1] - FDA warning information (from [3]): - Black box warning: None; - Warnings: Use with caution in heart failure patients (may increase risk of pulmonary edema); avoid in patients with severe aortic stenosis [3] |
Solubility Data
| Solubility (In Vitro) |
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| Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 2.5 mg/mL (4.41 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. Solubility in Formulation 2: ≥ 2.5 mg/mL (4.41 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. Solubility in Formulation 3: ≥ 2.5 mg/mL (4.41 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. Solubility in Formulation 4: 2 mg/mL (3.53 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication. (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 1.7635 mL | 8.8176 mL | 17.6351 mL | |
| 5 mM | 0.3527 mL | 1.7635 mL | 3.5270 mL | |
| 10 mM | 0.1764 mL | 0.8818 mL | 1.7635 mL |