Treatment in vivo with mezlocillin (subcutaneous injection; 1.7–5.7 mg/kg; twice daily; 7 days) resulted in suppression of delayed-type hypersensitivity reactions, IgM and IgG responses, hair loss, and decreased dosage of lymphocyte proliferation[1].

Animal/Disease Models: Male balb/c (Bagg ALBino) mouse [1]
Doses: 1.7, 4.3, and 5.7 mg/kg
Route of Administration: subcutaneous injection; 1.7, 4.3, and 5.7 mg/kg; twice (two times) daily; 7-day
Experimental Results: All dose treatments were Inhibits IgM and IgG responses as well as delayed-type hypersensitivity reactions. Hair loss was observed in most animals treated at all doses. Inhibits lymphocyte proliferation in animal spleen cell cultures.

Metabolism / Metabolites
Unlike many other penicillins, mezlocillin is either extensively metabolized or is subject to biliary excretion, as only about 50% of the dose was accounted for in normal urine.

---

Biological Half-Life
1.3 to 4.4 hours

Protein Binding
16-59%

[1]. Antibiotics and immunomodulation: effects of cefotaxime, amikacin, mezlocillin, piperacillin and clindamycin. Med Microbiol Immunol. 1985;173(5):279-89.

[2]. Mezlocillin: in vitro studies of a new broad-spectrum penicillin. Antimicrob Agents Chemother. 1977 Jan;11(1):74-9.

[3]. Treatment of accidental high dose intraventricular mezlocillin application by cerebrospinal fluid exchange. J Neurol Neurosurg Psychiatry. 1998 Mar;64(3):379-81.

Mezlocillin is a penicillin in which the substituent at position 6 of the penam ring is a (2R)-2-[3-(methanesulfonyl)-2-oxoimidazolidine-1-carboxamido]-2-phenylacetamido group. It has a role as an antibacterial drug. It is a penicillin and a penicillin allergen. It is a conjugate acid of a mezlocillin(1-).
Semisynthetic ampicillin-derived acylureido penicillin. It has been proposed for infections with certain anaerobes and may be useful in inner ear, bile, and CNS infections.
Mezlocillin has been reported in Bos taurus and Apis cerana with data available.
Mezlocillin is a broad-spectrum, beta-lactam penicillin antibiotic with antibacterial activity. Mezlocillin binds to and inactivates penicillin-binding proteins (PBP) located on the inner membrane of the bacterial cell wall. Inactivation of PBPs interferes with the cross-linkage of peptidoglycan chains necessary for bacterial cell wall strength and rigidity. This interrupts the final stage of bacterial cell wall synthesis and results in the weakening of the bacterial cell wall and eventually causing cell lysis.
Semisynthetic ampicillin-derived acylureido penicillin. It has been proposed for infections with certain anaerobes and may be useful in inner ear, bile, and CNS infections.
See also: Mezlocillin Sodium (annotation moved to).

---

Drug Indication
Used to treat serious gram–negative infections of the lungs, urinary tract, and skin.

---

Mechanism of Action
By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, mezlocillin inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins; it is possible that mezlocillin interferes with an autolysin inhibitor.

---

Pharmacodynamics
Mezlocillin is a penicillin beta-lactam antibiotic used in the treatment of bacterial infections caused by susceptible, usually gram-positive, organisms. The name "penicillin" can either refer to several variants of penicillin available, or to the group of antibiotics derived from the penicillins. Mezlocillin has in vitro activity against gram-positive and gram-negative aerobic and anaerobic bacteria. The bactericidal activity of mezlocillin results from the inhibition of cell wall synthesis and is mediated through mezlocillin binding to penicillin binding proteins (PBPs). Mezlocillin is stable against hydrolysis by a variety of beta-lactamases, including penicillinases, and cephalosporinases and extended spectrum beta-lactamases. Mezlocillin can be used to treat susceptible strains of H. influenzae, Klebsiella species, Pseudomonas species, Proteus mirabilis, E. coli, Enterobacter species, Streptococcus faecelis, Peptococcus species, Peptostreptococcus species, Bacteriodes species (including B. fragilis), Morganella morganii, Serratia species, N. gonorrhoeae, P. vulgaris, and Providencia rettgeri. This drug is discontinued in the U.S.

C21H25N5O8S2

539.581902265549

539.114

51481-65-3

Mezlocillin sodium;42057-22-7

656511

Typically exists as solid at room temperature

1.6±0.1 g/cm3

655.5ºC at 760 mmHg

350.2ºC

1.701

-1.18

3

9

6

36

1080

4

O=C([C@@H](C(C)(C)S[C@]1([H])[C@@H]2NC([C@H](NC(N3CCN(S(=O)(C)=O)C3=O)=O)C4=CC=CC=C4)=O)N1C2=O)O

YPBATNHYBCGSSN-VWPFQQQWSA-N

InChI=1S/C21H25N5O8S2/c1-21(2)14(18(29)30)26-16(28)13(17(26)35-21)22-15(27)12(11-7-5-4-6-8-11)23-19(31)24-9-10-25(20(24)32)36(3,33)34/h4-8,12-14,17H,9-10H2,1-3H3,(H,22,27)(H,23,31)(H,29,30)/t12-,13-,14+,17-/m1/s1

(2S,5R,6R)-3,3-dimethyl-6-[[(2R)-2-[(3-methylsulfonyl-2-oxoimidazolidine-1-carbonyl)amino]-2-phenylacetyl]amino]-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-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.

---

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).

View More

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)

---

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).

View More

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

---

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.

---

 (Please use freshly prepared in vivo formulations for optimal results.)