Absorption, Distribution and Excretion
Doripenem is administered intravenously as an infusion. There was no accumulation of doripenem following mulitiple infusions of either 500mg or 1g administered every 8 hours for 7-10 days in subjects with normal renal function.
Doripenem is primarily eliminated unchanged by the kidneys and undergoes glomerular filtration and active tubular secretion. A mean of 71% and 15% of the dose was recovered in urine as unchanged drug and the ring-opened metabolite, respectively, within 48 hours of 500 mg dose in healthy adults. Following the administration of a single 500 mg dose of radiolabeled doripenem to healthy adults, less than 1% of the total radioactivity was recovered in feces after one week.
The average Vd is 16.8 L (8.09-55.5 L) at steady-state in healthy subjects. Doripenem penetrates into many tissues and fluids, including potential sites of approved indication infections.
10.3 L/hour.

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Metabolism / Metabolites
Metabolism of doripenem is via dehydropeptidase-I (also called dipeptidase-1) into a microbiologically inactive ring-opened metabolite, doripenem-M1. Doripenem does not appear to be a substrate of the hepatic CYP450 enzymes.

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Biological Half-Life
1 hour, in healthy non-elderly adults.

Hepatotoxicity
Mild, transient, asymptomatic elevations in serum aminotransferase levels occur in 1% to 5% of patients receiving parenteral doripenem for 5 to 14 days. These abnormalities are usually self-limited and asymptomatic and rarely above 5 times the upper limit of normal. In the limited period that it has been available, no cases of hepatitis with jaundice have been reported. Nevertheless, several instances of cholestatic jaundice arising during or shortly after therapy have been reported with other carbapenems. The latency to onset has been within 1 to 3 weeks and the pattern of enzyme elevations is usually cholestatic. Immunoallergic features can occur, but autoantibodies are rare. The course is usually self-limiting, but at least one case of vanishing bile duct syndrome related to a carbapenem has been reported. Doripenem and other carbapenems have not been linked to cases of acute liver failure.
Likelihood score: E* (unproven but suspected cause of liver injury).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the clinical use of doripenem during breastfeeding. Its excretion into breastmilk is likely similar to that of imipenem and meropenem, which produce low levels in milk that are not expected to cause adverse effects in breastfed infants. Occasionally disruption of the infant's gastrointestinal flora, resulting in diarrhea or thrush has been reported with beta-lactams, but these effects have not been adequately evaluated. Doripenem is acceptable in nursing mothers.
◉ 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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Protein Binding
8.1%

Doripenem is a member of carbapenems.
Doripenem is a broad-spectrum, carbapenem antibiotic marketed under the brand name Doribax by Janssen. Doripenem injection was approved by the FDA in 2007 to treat complicated urinary tract and intra-abdominal infections. In a clinical trial of doripenem treatment in ventilator associated pneumonia (vs. imipenem and cilastatin), it was found that doripenem carried an increased risk of death and lower clinical cure rates, resulting in a premature termination of the trial. The FDA revised the doripenem label in 2014 to include a warning against use in ventilator-associated pneumonia and to reiterate its safety and efficacy for its approved indications.
Doripenem is a Penem Antibacterial.
Doripenem is a broad spectrum carbapenem antibiotic used primarily for the treatment of aerobic gram-negative bacterial infections. Doripenem, like other carbapenems, is associated with transient and asymptomatic elevations in serum enzymes. The carbapenems have also been linked to rare instances of clinically apparent, acute cholestatic liver injury.
Doripenem is a broad-spectrum, carbapenem antibiotic with bactericidal and beta-lactamase resistant activities. Doripenem binds to penicillin binding proteins (PBPs) located on the bacterial cell wall, particularly PBPs 2 and 3, thereby inhibiting the final transpeptidation step in the synthesis of peptidoglycan, an essential component of the bacterial cell wall. Inhibition results in a weakening and eventually lysis of the bacterial cell wall. This agent is two- to 16-fold more potent than imipenem and comparable to ertapenem and meropenem.
A carbapenem derivative antibacterial agent that is more stable to renal dehydropeptidase I than IMIPENEM, but does not need to be given with an enzyme inhibitor such as CILASTATIN. It is used in the treatment of infections such as HOSPITAL-ACQUIRED PNEUMONIA, and complicated intra-abdominal or urinary-tract infections, including PYELONEPHRITIS.

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Drug Indication
Doripenem is indicated in the treatment of complicated intra-abdominal infections and complicated urinary tract infections, including pyelonephritis, caused by designated susceptible bacteria.
FDA Label
Doribax is indicated for the treatment of the following infections in adults: nosocomial pneumonia (including ventilator-associated pneumonia); complicated intra-abdominal infections; complicated urinary tract infections. Consideration should be given to official guidance on the appropriate use of antibacterial agents.

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Mechanism of Action
Doripenem is a broad-spectrum carbapenem antibiotic with activity against many gram-positive and gram-negative aerobic bacteria, as well as a variety of anaerobes. Like other beta-lactam antibiotics, doripenem's bactericidal mechanism of action is mostly due to cell death after inhibition of bacterial enzymes called penicillin-bindng proteins (PBPs), which are responsible for peptidoglycan cross-linking during the synthesis of the bacterial cell wall. Carbapenems mainly have high affinity for PBPs 1a, 1b, 2 and 3. Inhibition of each PBP usually results in a different inactivating mechanism. Inhibition of PBPs 1a and 1b results in fast bacterial killing through the formation of spheroplasts, inhibition of PBP 2 results in rod-shaped bacteria to become spherical, and inhibition of PBP 3 results in filamentous-shaped organisms. The PBPs preferentially bound by different carbapenems depend on the organism. In E.coli and P.aeruginosa, doripenem binds to PBP 2, which is involved in the maintenance of cell shape, as well as to PBPs 3 and 4. Doripenem has a 1-beta-methyl side chain, which allows it to be relatively resistant to dehydropeptidase, as well as a trans-alpha-1-hydroxyethyl group at position 6 which provides beta-lactamase resistance. Like other carbapenems, doripenem is different from most beta-lactams due to its stability against hydrolysis by most beta-lactamases, including penicillinases, cephalosporinases, ESBL, and Amp-C producing enterobacteriaceae.

C15H24N4O6S2

420.5

420.113

148016-81-3

Doripenem monohydrate;364622-82-2

73303

Typically exists as solid at room temperature

1.6±0.1 g/cm3

694.8±65.0 °C at 760 mmHg

>186ºC dec.

374.0±34.3 °C

0.0±4.9 mmHg at 25°C

1.681

-3.65

5

10

7

27

780

6

O=C(C(N12)=C(S[C@@H]3CN[C@H](CNS(=O)(N)=O)C3)[C@H](C)[C@]2([H])[C@@H]([C@H](O)C)C1=O)O

AVAACINZEOAHHE-VFZPANTDSA-N

InChI=1S/C15H24N4O6S2/c1-6-11-10(7(2)20)14(21)19(11)12(15(22)23)13(6)26-9-3-8(17-5-9)4-18-27(16,24)25/h6-11,17-18,20H,3-5H2,1-2H3,(H,22,23)(H2,16,24,25)/t6-,7-,8+,9+,10-,11-/m1/s1

(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-3-[(3S,5S)-5-[(sulfamoylamino)methyl]pyrrolidin-3-yl]sulfanyl-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid

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)

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.)