In its unaltered active state, sulfadiazine is quickly absorbed and nearly totally eliminated in the urine [1].

Absorption, Distribution and Excretion
Absorbed well after oral administration.
Sulfacytidine…is rapidly absorbed after oral administration. Over 90% of the drug is almost entirely excreted via the kidneys in its free active form. …86% is bound to serum proteins. …This drug can cross the placenta and be secreted into breast milk…
Compared to the urinary concentration of sulfamethoxazole, 1 g/day of sulfacytidine appears to be a suitable therapeutic dose, with a urinary concentration at least 10 times the maximum and minimum inhibitory concentrations (MICs) for susceptible microorganisms.
Sulfacytidine is highly soluble in urine within the normal acidic pH range.
34 subjects were randomly assigned to three groups: groups of 12, 12, and 10. Group 1 received 250 mg of sulfacytidine four times daily; Group 2 received 500 mg of sulfacytidine four times daily; and Group 3 received a placebo. Renal function remained unchanged during the 84-day trial. Renal function is assessed using creatinine clearance, blood urea nitrogen, urinalysis, and phenolsulfonphthalein excretion test. For more complete data on the absorption, distribution, and excretion of sulfadiazines (11 in total), please visit the HSDB record page. Metabolism/Metabolites Sulfonamides undergo varying degrees of metabolic alteration in tissues, particularly the liver. Both acetylation and oxidation can occur. …In almost all species, the major metabolic derivative is N4-acetylated sulfonamide. /Sulfonamides/ While the liver is the primary site of metabolism, sulfonamides can also be metabolized in other body tissues. Most sulfonamides are primarily metabolized via N4-acetylation. The degree of acetylation varies over time, ranging from less than 5% for sulfamethhiazole to as high as 40% for sulfadiazine. N4-acetylated metabolites lack antibacterial activity, have a higher affinity for plasma albumin compared to unacetylated drugs, and are generally less soluble than the parent sulfonamide, especially in acidic urine. Like acetylated derivatives, glucuronide derivatives do not possess antibacterial activity; however, glucuronide derivatives are water-soluble, their plasma binding capacity appears similar to that of unacetylated sulfonamides, and no adverse reactions have been observed. /Sulfonamides/

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Biological Half-Life
The biological half-life of sulfamethoxazole is approximately 4 hours…

Interactions
Certain sulfonamides may displace coumarin or indanedione derivative anticoagulants, phenytoin anticonvulsants, or oral hypoglycemic agents from their protein binding sites and/or inhibit their metabolism, leading to enhanced or prolonged effects and/or toxicity; dose adjustments may be necessary during and after sulfonamide treatment. /Sulfonamides/
Concomitant use of sulfonamides with myelosuppressants may increase the incidence of leukopenia and/or thrombocytopenia; if concomitant use is necessary, close monitoring for myelotoxicity is required. /Sulfonamides/
Prolonged concomitant use of sulfonamides with estrogen-containing oral contraceptives may increase the incidence of breakthrough bleeding and pregnancy. Sulfonamides
Concomitant use of cyclosporine with sulfonamides may increase cyclosporine metabolism, leading to decreased plasma concentrations and potentially causing transplant rejection, as well as additive nephrotoxicity; plasma cyclosporine concentrations and renal function should be monitored. Sulfonamides
For more complete data on drug interactions of sulfamethoxazoles (13 in total), please visit the HSDB record page.

[1]. J Hughes, et al. Sulfacytine: A New Sulfonamide. Double-blind Comparison With Sulfisoxazole in Acute Uncomplicated Urinary Tract Infections. J Urol. 1975 Dec;114(6):912-4.

Therapeutic Uses

Anti-infectives/SRP: Antibacterial Drugs/
Sulfacytidine is used to treat acute urinary tract infections caused by susceptible Escherichia coli, Klebsiella pneumoniae-Enterobacteria, Staphylococcus aureus, Proteus mirabilis, and less commonly Proteus vulgaris.
Sulfonamides are indicated for the treatment of chancroid caused by Haemophilus ducreyi. However, other drugs, such as erythromycin and ceftriaxone, are considered the first-line treatment. /Sulfonamides; included in US product label/
Sulfonamides are indicated for the treatment of cervical endometrial and urinary tract infections caused by Chlamydia trachomatis. However, other drugs, such as doxycycline and azithromycin, are considered the first-line treatment. /Sulfonamides; included in US product label/
For more complete data on the therapeutic uses of sulfadiazines (15 in total), please visit the HSDB record page.

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Drug Warnings
Due to the development of more effective antibacterial drugs and the increasing resistance of many bacteria to these drugs, the therapeutic uses of sulfonamides and the number of diseases for which they are the first-line treatment have significantly decreased. /Sulfonamides/
Although the risk of crystalluria appears to be small, fluid intake should still be increased when taking this drug. Patients with impaired renal function should use sulfacyline with caution.
Since there are currently no well-controlled clinical studies, sulfacyline is contraindicated in pregnant women unless the expected benefit outweighs the potential adverse effects.
Sulfacyline is contraindicated in patients with hypersensitivity to sulfonamides.
For more complete data on drug warnings for sulfacyline (26 in total), please visit the HSDB records page.

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Pharmacodynamics
Sulfacyline is a short-acting sulfonamide. Sulfonamides are synthetic antibacterial antibiotics with broad-spectrum antibacterial activity against most Gram-positive bacteria and many Gram-negative bacteria. However, many strains of the same species may be resistant. Sulfonamides inhibit bacterial growth by competitively inhibiting para-aminobenzoic acid in the folate metabolic cycle. Various sulfonamides exhibit similar bacterial susceptibility; resistance to one sulfonamide implies resistance to all sulfonamides. Most sulfonamides are well absorbed orally. However, parenteral administration is challenging due to the strong alkalinity and tissue irritation of soluble sulfonamide salts. Sulfonamides are widely distributed in all tissues, with high concentrations in pleural fluid, peritoneal fluid, synovial fluid, and ocular fluid. Although these drugs are no longer used to treat meningitis, high concentrations of sulfonamides remain in cerebrospinal fluid during meningitis infections. Pus can inhibit their antibacterial activity.

C12H14N4O3S

294.329

294.079

17784-12-2

5322

Crystals from butyl alcohol, methanol
Crystalline

1.45g/cm3

496.8ºC at 760mmHg

166.5-168ºC

254.2ºC

5.25E-10mmHg at 25°C

1.664

2.381

2

4

4

20

527

0

CCN1C=CC(=NC1=O)NS(=O)(=O)C2=CC=C(C=C2)N

SIBQAECNSSQUOD-UHFFFAOYSA-N

InChI=1S/C12H14N4O3S/c1-2-16-8-7-11(14-12(16)17)15-20(18,19)10-5-3-9(13)4-6-10/h3-8H,2,13H2,1H3,(H,14,15,17)

4-amino-N-(1-ethyl-2-oxopyrimidin-4-yl)benzenesulfonamide

CI 636; CI-636; CI636

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 : ~125 mg/mL (~424.69 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.)