Penicillin G Benzathine

Benzathine Benzylpenicillin1.0 % lec., 0.2 % Tween, pulverized, sterile

Molecular formula:
2(C16H18N2O4S).C16H20N2.4H2O
Molecular weight:
981.2
CAS registry no.:
41372-02-5
 Benzathine

Application

Mainly used for the manufacture of powders for injection (vials); the product can be filled into vials using any customary filling machine. A homogeneous suspension is prepared by adding water for injection and shaking briefly. For better wettability and suspendibility the material is coated with 1.0 % of lecithin and 0.2 % of Tween.

Antibiotic category

Depot penicillin for long-acting blood levels

Packaging

Storage

Store below 25°C,
Protect from light and moisture

Shelf life

60 months

Specification

Appearancewhite to whitish, crystalline powder
Particle sizex(50,3): 14 - 24 µm
80 %: 4 - 50 µm
exceeding 70 µm:
informative
exceeding 125 µm:
informative
Injection testcorresponding (needle diameter: not more than 300 µm)
Acidity or alkalinitycorresponding to BP/Ph.Eur.
Water content
(Karl Fischer)		5.0 – 8.0 %
pH-value4.0 – 6.5
Sterility
(USP/Ph.Eur.)		sterile
Bacterial endotoxins
(LAL-test/USP)		not more than 0.010 EU/100 IU
Largest impurity
(Ph.Eur./HPLC)		not more than 1.0 %
Benzylpenicilloic acid benzathide
(Ph.Eur./HPLC)		not more than 2.0 %
Assay/Content
  • Penicillin G Benzathine (HPLC):
    96.0 - 102.0 % 1)
  • Penicillin G (HPLC):
    61.4 - 71.6 %
    65.0 - 76.0 % 1)
  • Benzathine (HPLC):
    24.0 - 27.0 % 1)
  • Lecithin (HPTLC):
    0.5 - 1.5 %
  • Polysorbate (HPTLC):
    0.1 - 0.3 %
1) Based on the anhydrous and non-coated substance

Pharmacopoeial quality

The active substance corresponds to USP, BP, Ph.Eur.