Poster Presentation 20th Lancefield International Symposium on Streptococci and Streptococcal Diseases 2017

Global quality of benzathine penicillin G (BPG) – is potency an issue? (#211)

Ganga Senarathna 1 , Robert M Hand 2 3 , Madhu Page-Sharp 1 , Kevin T Batty 1 , Laurens Manning 4 5 , Katherine Gray 6 , Dianne Sika-Paotonu 3 7 , Jonathan Carapetis 3 8
  1. School of Pharmacy and Curtin Health Innovation Research Institute, Curtin Univeristy of Technology, Perth, Western Australia, Australia
  2. Department of General Medicine, Fiona Stanely Hospital, Murdoch, Western Australia, Australia
  3. Telethon Kids Institute, University of Western Australia, Subiaco, Western Australia, Australia
  4. School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia
  5. Infectious Diseases Department, Fiona Stanely Hospital, Murdoch, Western Australia, Australia
  6. Telethon Kids Institute, University of Western Australia, Subiaco, Western Australia, Australia
  7. Graduate School of Nursing, Midwifery & Health, Victoria University of Wellington, Wellington, New Zealand
  8. Princess Margaret Hospital for Children, Perth, Western Australia, Australia


BPG is used widely for the treatment many infections.  It is recommended as the first line therapy for acute rheumatic fever prophylaxis as well as syphilis treatment in most cases.  Clinicians have often used newer medications owing to a number misconceptions around BPG, including questioning the potency of supply and effectiveness of BPG.  As such, newer broad spectrum agents are often used.  Clinician confidence in BPG is a cornerstone of rheumatic heart disease control programs as Streptococcus pyogenes remains universally sensitive to penicillin.


To reassure clinicians that commercially available BPG preparations are stable and are manufactured to good manufacturing practice.


BPG donated from 10 countries were used for high performance liquid chromatography (HPLC) analysis.  Two milligrams of powdered BPG was extracted from each vial, diluted in 1ml of dimethylformamide, then analysed using HPLC for potency and degradation products (penicilloic acid).  Inter-batch variability was also tested when supplied.  Thermal stability of Bicillin® was assessed over six months at 35°C.


Samples provided contained a nominal range of between 96.6% (95% CI 93.3-99.7) and 106.7% (95%CI 102.0-111.3) of BPG.  No evidence of degradation products was detected.  Thermal stress of Bicillin® showed no significant degradation products at six months.


Preliminary data suggest that supply of BPG is of sufficient quality, as per manufacturing specifications. Supplied samples showed no evidence of degradation in tropical temperatures. Simulated stability testing suggests that unmixed Bicillin® can be kept outside the fridge for short periods at room temperature without premature degradation as per manufacturer guidelines.