Absorption, Distribution and Excretion
Barium sulfate is not absorbed following oral or rectal administration with a normal gastrointestinal tract. In patients with a normal GI tract, barium sulfate is normally excreted within 24 hr after oral ingestion. Post rectal administration of barium sulfate suspensions, the drug is generally excreted when the enema is released. Some barium may remain in the colon for several weeks, however, and eventually clears, especially in patients with impaired intestinal peristalsis. It is difficult to quantify the uptake of ingested barium because of a number of factors affect its absorption. The presence of sulfate in food can cause the precipitation of barium sulfate. The following is the approximate time to peak opacification of organs by barium sulfate in a healthy GI tract: Esophagus, stomach, and duodenum uptake of barium sulfate occurs almost immediately after oral administration. Small intestine uptake is dependent on gastric emptying rate and viscosity of the preparation; it may be delayed 15-90 minutes post ingestion. Small intestine (enteroclysis studies) uptake is immediate, following direct instillation. Colon and distal small intestine uptake are dependent on patient positioning. Hydrostatic pressure also determines the rate and degree of opacification.
Barium sulfate is excreted unchanged in the feces.
The rate of excretion of barium sulfate is dependent on the route of administration and the status of peristaltic activity and motility of the gastrointestinal tract.
/In female beagle dog,/ (131)barium sulfate was found to be cleared from lung, with a biological half-time of 8-9 days ... . This indicated some solubility ... In body fluids, possibly in colloidal form. ... Barium sulfate ... Clearance rate /depends/ on specific surface area of inhaled particles and was lower for heat treated than for untreated particles.
In an extensive study, temperature and pulse rate measurements were taken as an indication of an acute inflammatory response for 291 humans administered a single unstated dose of a 50% w/v barium sulfate suspension for bronchographic purposes. The method of administration was unstated, but the suspension was presumed to have been instilled into the trachea and then blown into the lungs. In 154 patients, there was radiological evidence of the presence of barium sulfate in the bronchial tree at the time of the last available X-ray (various time points ranging from < 1 week to > 1 year after administration); in 135 patients, on the other hand, there was no radiological evidence of residual barium sulfate in the lungs 1 year after bronchography. Forty-one of these patients exhibited complete elimination of the barium sulfate from the lungs within 1 week; it was stated that in some of these patients, this clearance occurred within 24 hr.
After inhalation exposure of rats to a BaSO4 aerosol at 40 mg/cu m, 5 hr daily for 2 months, lymphatic transport was slight. The skeletal concentration of Ba was 0.8-1.5 mg/g dry substance (10-100 times the pulmonary concentration). Skeletal uptake decreased somewhat with advancing age.
Of BaSO4 injected intratracheally, about 5% of the initial dose was recovered in the urine during the first 10 days after administration.
For more Absorption, Distribution and Excretion (Complete) data for Barium sulfate (11 total), please visit the HSDB record page.

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Metabolism / Metabolites
Barium sulfate is poorly water soluble and shows negligible levels of absorption from the gastrointestinal tract following both oral or rectal administration. In healthy subjects, orally administered barium sulfate is generally excreted within 24 hours. Rectally administered barium sulfate is eliminated with clearance of the enema.
The in vivo solubility in rats of barium chloride, barium carbonate, barium sulfate, and barium fused in clay /was studied/. The chloride and the carbonate disappeared rapidly from the injection site. The sulfate dissolved more slowly; a half-life of 26 days was calculated. The fused clay was largely retained, the half-life being calculated as 1390 days.
Barium compounds are absorbed via ingestion and inhalation, the extent of which depends on the individual compound. In the body, the majority of the barium is found in the bone, while small amounts exists in the muscle, adipose, skin, and connective tissue. Barium is not metabolized in the body, but it may be transported or incorporated into complexes or tissues. Barium is excreted in the urine and faeces. (L214)

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Biological Half-Life
... In rats barium sulfate disappeared from the injection site with a half-life of 26 days ...
In Syrian hamsters, barium sulfate was found to be cleared from the lungs with a biological half-life of 8-9 days ...
(131)BaSO4 was found to be cleared from the lungs, with a biological half-life time of 8-9 days, through absorption into the general circulation with subsequent urinary clearance.
Measurements of the clearance of tracer levels of (131)barium sulfate (estimated maximum initial burden of 90 ug or 0.09 mg/kg from a 30 to 90 minute exposure) from the respiratory tract of female beagle dogs (10 + or - 1 kg) were performed. The biological half-life was eight days.
/Barium/ sulfate ... /has a calculated/ half-life of 26 days /in rats/.

Toxicity Summary
IDENTIFICATION: In nature barium occurs in a combined state, the principal forms being barite (barium sulfate) and witherite (barium carbonate). Barium sulfate has a very low water solubility. Barite ore is the raw material from which nearly all other barium compounds are derived. Barium and its compounds are used in diverse industrial products ranging from ceramics to lubricants. It is used in the manufacture of alloys, as a loader for paper, soap, rubber and linoleum, in the manufacture of valves and as an extinguisher for radium, uranium and plutonium fires. Anthropogenic sources of barium are primarily industrial. Emissions may result from mining, refining or processing barium minerals and the manufacture of barium products. Mining and processing of barite ore releases particulates into the air and from fugitive dusts from the use of barite in oil drilling and oil related industries. HUMAN EXPOSURE: It is difficult to assess the uptake of ingested barium because of a number of factors affect absorption. The presence of sulfate in food results in the precipitation of barium sulfate. ANIMAL/PLANT STUDIES: Insoluble barium compounds such as barium sulfate, accumulate in the lungs and are cleared slowly ciliary action.
Barium is a competitive potassium channel antagonist that blocks the passive efflux of intracellular potassium, resulting in a shift of potassium from extracellular to intracellular compartments. The intracellular translocation of potassium results in a decreased resting membrane potential, making the muscle fibers electrically unexcitable and causing paralysis. Some of these barium's effects may also be due to barium induced neuromuscular blockade and membrane depolarization. (L214)

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Because barium sulfate is not absorbed after oral or rectal administration, it will not enter the milk, reach the bloodstream of the infant or cause any adverse effects in breastfed infants. No special precautions are required.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Non-Human Toxicity Values
LD50 Rat oral approx 307,000 mg/kg bw
LD50 Mouse oral > 3000 mg/kg bw

[1]. Biochemical reagents[M]//Methods of Enzymatic Analysis. Academic Press, 1965: 967-1037.

Therapeutic Uses
A compound used as an x-ray contrast medium that occurs in nature as the mineral barite.
Barium sulfate suspension is indicated for use as a contrast medium in x-ray diagnosis of the gastrointestinal tract. /Included in US product label/
This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA.
Oral or rectal barium sulfate suspension, in low concentration, is indicated for enhancement of computed tomographic images (CT of the body) to delineate the gastrointestinal tract. /Included in US product labeling/
For more Therapeutic Uses (Complete) data for Barium sulfate (18 total), please visit the HSDB record page.

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Drug Warnings
/VET/ Unless intestinal tract evacuates itself promptly, large masses of drug can produce an impaction. Peritoneal leakage has been associated with peritonitis, possibly secondary to ... fecal leakage. Use approved grades ... impure forms may be associated with metaplasia at ulcer sites in dogs.
Rarely, oral barium sulfate suspensions may cause constipation or intestinal obstruction due to impaction in the colon. Cramping from distention of the intestine by barium sulfate suspensions or diarrhea may also occur. Retention of barium sulfate in the appendix has reportedly caused appendicitis. Barium sulfate fecaliths reported can lead to obstruction, intussusception, ulceration, or even intestinal perforation and may rarely require surgical removal. ... Aspiration of large amt may cause pneumonitis or nodular granulomas of interstitial lung tissues and lymph nodes; asphyxiation and death have occurred in one patient.
Users must be certain that barium sulfate is not contaminated by sol barium salts. A convenient test is to shake up a portion with water and, to the clear supernatant portion, add a small amt of a soln of magnesium sulfate in water. Appearance of a precipitate indicates the presence of a sol barium salt.
Barium sulfate products are contraindicated in patients with known or suspected obstruction of the colon, known or suspected gastrointestinal tract perforation, suspected tracheoesophageal fistula, obstructing lesions of the small intestine, pyloric stenosis inflammation or neoplastic lesions of the rectum, recent rectal biopsy, or known hypersensitivity to barium sulfate formulations.
For more Drug Warnings (Complete) data for Barium sulfate (49 total), please visit the HSDB record page.

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Pharmacodynamics
Barium sulfate increases the absorption of x-rays as they are passed throughout the body, delineating body structures, in which barium sulfate is localized. This allows for the clear visualization of normal organs/defect in normal anatomy.

BASO4

233.39

233.856

7727-43-7

24414

Fine, heavy powder or polymorphous crystals
White, orthorhombic crystals
White or yellowish powder
Opaque powder

4.5

330ºC at 760 mmHg

1580ºC

0

4

0

6

62.2

0

[Ba+2].S(=O)(=O)([O-])[O-]

TZCXTZWJZNENPQ-UHFFFAOYSA-L

InChI=1S/Ba.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2

barium(2+);sulfate

Baryta white

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

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.)