Brand Name

Not specified

Dosage Form



Not specified


Not specified

Conditions Studied

  • Drug batches from stocks in central distribution facilities were sampled and retained
  • In outlying clinics, samples were taken of:
    • the oldest batch of each drug: intended to reveal degradation if the drug was unstable
    • batches of drug with the same lot number as those in the central distribution facility: intended to reveal changes in stability over time when compared with samples from the central facility

Temperature (degrees Celsius)

Not specified

Humidity (%)

Not specified

Countries Studied In

Harare and Bulawayo, Zimbabwe

Definition of Stability

Meet British Pharmacopeia potency standards (95-105% of stated)

Conclusions and Length of Stability
  • Manufacturer's stated shelf life: 2 years
  • 2/10 (20%) of central facility samples failed
    • Both were below, at 86.8% and 90.9%
    • One failure occurred at two months, suggesting an initial quality problem
  • 5/24 (20%) of the outlying clinic samples were below the lower limit (a similar rate as the central facility)
  • There was an insignificant (-1.1%) loss of potency in 13 central facility/outlying clinic pairs (samples with matched lot numbers)
  • Many samples passed potency testing at or beyond expiry
  • Authors' conclusions:
    • Failures appear to be due to an initial quality problem, as evidenced by similar rates of failure among central facility and outlying clinic samples
    • Ampicillin injection appears to be stable as long as initial quality can be assured


Nazerali H, Muchemwa T, Hogerzeil HV. Stability of essential drugs in tropical climates: Zimbabwe. World Health Organization Action Programme on Essential Drugs. Accessed August 3, 2010 at:

MeSH Entry Terms
  • Aminobenzylpenicillin
  • Penicillin, Aminobenzyl
  • Aminobenzyl Penicillin
  • Ampicillin Sodium
  • Sodium, Ampicillin
  • Ampicillin Trihydrate
  • Trihydrate, Ampicillin
  • Antibiotic KS-R1
  • Antibiotic KS R1
  • KS-R1, Antibiotic
  • Pentrexyl
  • Polycillin
  • Ukapen
  • Amcill
  • Omnipen
MeSH Reference:
Written by: Alex Evans, PharmD
Reviewed by: