In primary bronchial epithelial cells from asthmatic patients, azithromycin (2 μM) increases rhinovirus-induced IFNβ expression. This is linked to upregulation of RIG-I-like receptors and suppression of viral propagation. In virus-induced asthma, azithromycin (2 μM)-enhanced IFNβ production in primary bronchial epithelial cells is reduced by MDA5 knockdown but not RIG-I knockdown [1]. Without altering NF-κB, azithromycin selectively lowers MMP-9 mRNA and protein levels in endotoxin-challenged mononuclear THP-1 cells [2].

A mouse model of acute asthma exacerbation treated with 50 mg/kg of azithromycin showed no change in bronchoalveolar lavage inflammatory markers and LDH levels. In a mouse model of asthma exacerbation, azithromycin did not cause any general inflammatory parameters or LDH release. However, it did enhance the expression of interferon-stimulated genes and the pattern recognition receptor MDA5, but not RIG-I[1].

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Because of the low levels of azithromycin in breastmilk and use in infants in higher doses, it would not be expected to cause adverse effects in breastfed infants. Monitor the infant for possible effects on the gastrointestinal flora, such as vomiting, diarrhea, candidiasis (thrush, diaper rash). Unconfirmed epidemiologic evidence indicates that the risk of infantile hypertrophic pyloric stenosis might be increased by maternal use of macrolide antibiotics during the first two weeks of breastfeeding, but others have questioned this relationship. In one study, a single dose of azithromycin given during labor to women who were nasal carriers of pathogenic Staphylococcus and Streptococcus reduced the counts of these bacteria in breastmilk, but increased the prevalence of azithromycin-resistant E. coli and K. pneumoniae in breastmilk.
Maternal use of an eye drop that contains azithromycin presents negligible risk for the nursing infant. To substantially diminish the amount of drug that reaches the breastmilk after using eye drops, place pressure over the tear duct by the corner of the eye for 1 minute or more, then remove the excess solution with an absorbent tissue.
◉ Effects in Breastfed Infants
A cohort study of infants diagnosed with infantile hypertrophic pyloric stenosis found that affected infants were 2.3 to 3 times more likely to have a mother taking a macrolide antibiotic during the 90 days after delivery. Stratification of the infants found the odds ratio to be 10 for female infants and 2 for male infants. All the mothers of affected infants nursed their infants. Most of the macrolide prescriptions were for erythromycin, but only 7% were for azithromycin. However, the authors did not state which macrolide was taken by the mothers of the affected infants.
A retrospective database study in Denmark of 15 years of data found a 3.5-fold increased risk of infantile hypertrophic pyloric stenosis in the infants of mothers who took a macrolide during the first 13 days postpartum, but not with later exposure. The proportion of infants who were breastfed was not known, but probably high. The proportion of women who took each macrolide was also not reported.
A study comparing the breastfed infants of mothers taking amoxicillin to those taking a macrolide antibiotic found no instances of pyloric stenosis. However, most of the infants exposed to a macrolide in breastmilk were exposed to roxithromycin. Only 10 of the 55 infants exposed to a macrolide were exposed to azithromycin. Adverse reactions occurred in 12.7% of the infants exposed to macrolides which was similar to the rate in amoxicillin-exposed infants. Reactions included rash, diarrhea, loss of appetite, and somnolence.
Eight women who were given azithromycin 500 mg intravenously 15, 30 or 60 minutes prior to incision for cesarean section breastfed their newborn infants. No adverse events were noted in their infants.
Two meta-analyses failed to demonstrate a relationship between maternal macrolide use during breastfeeding and infantile hypertrophic pyloric stenosis.
◉ Effects on Lactation and Breastmilk
In a double-blind, controlled study in Gambia, women who were nasopharyngeal carriers of Staphylococcus aureus, Streptococcus pneumoniae or group B streptococcus were given a single 2 gram dose of azithromycin during labor. Milk samples from women who received azithromycin had 9.6% prevalence of carriage of the organisms compared to 21.9% in women who received placebo. Nasopharyngeal carriage in mothers and infants was also reduced on day 6 postpartum. However, a later analysis found oral intrapartum azithromycin did not reduce carriage of Escherichia coli and Klebsiella pneumoniae and was associated with an increase in the prevalence of azithromycin-resistant E. coli and K. pneumoniae isolates in breastmilk.

[1]. Azithromycin augments rhinovirus-induced IFNβ via cytosolic MDA5 in experimental models of asthma exacerbation. Oncotarget. 2017 Mar 18.

[2]. Differential inhibition of activity, activation and gene expression of MMP-9 in THP-1 cells by azithromycin and minocycline versus bortezomib: A comparative study. PLoS One. 2017 Apr 3;12(4):e0174853.

Azithromycin dihydrate is a hydrate. It contains an azithromycin.
Azithromycin is an antibacterial prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of certain bacterial infections, such as:
Various bacterial respiratory diseases, including community-acquired pneumonia, acute sinus and ear infections, acute worsening of chronic bronchitis, and throat and tonsil infections
Pelvic inflammatory disease
Genital ulcer disease and infections of the urethra and cervix
Infections of the skin
Community-acquired pneumonia, a bacterial respiratory disease, can be an opportunistic infection (OI) of HIV.
Azithromycin Dihydrate is the dihydrate form of azithromycin, an orally bioavailable azalide derived from erythromycin, and a member of a subclass of macrolide antibiotics, with anti-bacterial activity. Upon oral administration, azithromycin reversibly binds to the 23S rRNA of the 50S ribosomal subunit of the bacterial ribosome of susceptible microorganisms, thereby inhibiting the translocation step of protein synthesis by preventing the assembly of the 50S ribosomal subunit. This inhibits bacterial protein synthesis, inhibits cell growth and causes cell death.
A semi-synthetic macrolide antibiotic structurally related to ERYTHROMYCIN. It has been used in the treatment of Mycobacterium avium intracellulare infections, toxoplasmosis, and cryptosporidiosis.
See also: Azithromycin dihydrate; trovafloxacin mesylate (component of).

C38H76N2O14

785.026

784.529

117772-70-0

Azithromycin;83905-01-5;Azithromycin-d3;163921-65-1

3033819

White to off-white solid powder

1.18g/cm3

822.1ºC at 760mmHg

113-115ºC

451ºC

2.51E-31mmHg at 25°C

1.71

7

16

7

54

1150

18

C[C@@H]([C@@H]([C@@](C(O[C@@H]([C@@](C)(O)[C@@H]1O)CC)=O)([H])C)O[C@@](O[C@@H](C)[C@@H]2O)([H])C[C@@]2(C)OC)[C@H]([C@](O)(C[C@H](CN([C@@H]1C)C)C)C)O[C@@](O[C@H](C)C[C@@H]3N(C)C)([H])[C@@H]3O.O.O

Azitro CP-62993 CP 62993

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: (1). This product requires protection from light (avoid light exposure) during transportation and storage.  (2). Please store this product in a sealed and protected environment (e.g. under nitrogen), 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.)