Absorption, Distribution and Excretion
Mean plasma concentration of magnesium after administration of oral doses of magnesium citrate are reported to be of around 0.7 mmol/L and the concentration in saliva rested in 0.28 mmol/L. In reports, it has also been proven that the absorption and bioavailability of magnesium are greater when administered in the form of magnesium citrate when compared with other forms such as magnesium ocude.
After oral administration of magnesium citrate, there is a 40% increase in urine excretion of magnesium. Magnesium citrate is also widely eliminated via the feces because, when present in the bowel, it relaxes the bowel and pulls water into the intestine which increases bowel movement and a significant portion of this agent gets excreted by this via.

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Biological Half-Life
The study of the half-life of magnesium citrate is very difficult due to the half-life of the available isotopes for magnesium.

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the clinical use of magnesium citrate during breastfeeding. However, other magnesium salts have been studied. Intravenous magnesium sulfate increases milk magnesium concentrations only slightly. Oral absorption of magnesium by the infant is poor, so maternal magnesium citrate is not expected to affect the breastfed infant's serum magnesium. Magnesium citrate supplementation during pregnancy might delay the onset of lactation, but it can be taken during breastfeeding and no special precautions are required.
◉ Effects in Breastfed Infants
Fifty mothers who were in the first day postpartum received 15 mL of either mineral oil or an emulsion of mineral oil and another magnesium salt, magnesium hydroxide equivalent to 900 mg of magnesium hydroxide, although the exact number who received each product was not stated. Additional doses were given on subsequent days if needed. None of the breastfed infants were noted to have any markedly abnormal stools, but all of the infants also received supplemental feedings.
◉ Effects on Lactation and Breastmilk
One mother who received intravenous magnesium sulfate for 3 days for pregnancy-induced hypertension had lactogenesis II delayed until day 10 postpartum. No other specific cause was found for the delay, although a complete work-up was not done. A subsequent controlled clinical trial found no evidence of delayed lactation in mothers who received intravenous magnesium sulfate therapy. Some, but not all, studies have found a trend toward increased time to the first feeding or decreased sucking in infants of mothers treated with intravenous magnesium sulfate during labor because of placental transfer of magnesium to the fetus.
A study in 40 pairs of matched healthy women with vaginally delivered singleton pregnancies, outcome endpoints were compared in those receiving continuous oral magnesium aspartate HCl supplementation mean dose of 459 mg daily (range 365 to 729 mg of magnesium daily) for at least 4 weeks before delivery versus non-supplemented controls. In the magnesium group, significantly fewer women could breastfeed their infants exclusively at discharge (63% vs 80%).

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Protein Binding
Magnesium, once ionized, is highly bound to plasma proteins and it can represent even 90% of the magnesium found in blood plasma.

[1]. Magnesium Citrate Increases Pain Threshold and Reduces TLR4 Concentration in the Brain. Biol Trace Elem Res. 2021;199(5):1954-1966.

Trimagnesium dicitrate is a magnesium salt composed of magnesium and citrate ions in a 3:2 ratio. It has a role as a laxative. It contains a citrate(3-).
Magnesium citrate is a low volume and osmotic cathartic agent. The cathartic action works primarily through the high osmolarity of the solution which draws large amounts of fluid into space where is used. Magnesium citrate is considered by the FDA as an approved inactive ingredient for approved drug products under the specifications of oral administration of a maximum concentration of 237 mg. It is also considered as an active ingredient in over-the-counter products.
Magnesium Citrate is the citrate salt of the element magnesium with cathartic activity. The cathartic action of magnesium cations appears to result, in part, from osmotically mediated water retention, which subsequently stimulates peristalsis. In addition, magnesium ions may also stimulate the activity of nitric oxide (NO) synthase and increase the biosynthesis of the phospholipid proinflammatory mediator platelet activating factor (PAF) in the gut. NO may stimulate intestinal secretion via prostaglandin- and cyclic GMP-dependent mechanisms while PAF produces significant stimulation of colonic secretion and gastrointestinal motility.
See also: Magnesium Cation (has active moiety) ... View More ...

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Drug Indication
Magnesium citrate has been used in bowel preparations prior to a colonoscopy as a cathartic agent. It is also used in over-the-counter products to relieve occasional constipation. Magnesium citrate can be one of the forms used for the administration of dietary supplements.

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Mechanism of Action
It mainly works through its property of high osmolality which will draw large amounts of fluid into the colonic lumen. There is also a possible stimulation of fluid excretion by cholecystokinin release and activation of muscle peristalsis.

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Pharmacodynamics
The onset of action can be as early as 30 minutes after administration with a mean onset time of approximately 2 hours and a maximum action of 4 hours. The effect of magnesium citrate is highly dependent on the individual's hydration status.

C12H10MG3O14

451.11

449.962

3344-18-1

6099959

White to off-white solid powder

309.6ºC at 760 mmHg

155.2ºC

2

14

4

29

211

0

PLSARIKBYIPYPF-UHFFFAOYSA-H

InChI=1S/2C6H8O7.3Mg/c2*7-3(8)1-6(13,5(11)12)2-4(9)10;;;/h2*13H,1-2H2,(H,7,8)(H,9,10)(H,11,12);;;/q;;3*+2/p-6

trimagnesium;2-hydroxypropane-1,2,3-tricarboxylate

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)

H2O: 4.72 mg/mL (10.46 mM)

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.)