Brand Name

Not specified

Dosage Form

Oral capsule


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 (BP) potency standards (92.5-110%)

Conclusions and Length of Stability

  • Manufacturer's stated shelf life: 3 years (1 manufacturer included in study)
  • All central facility samples met BP standards (mean value 100.1%)
  • 1/28 (4%) outlying clinic samples failed (assay value 92.4%) at age 28.5 months
  • No consistent loss of potency was found in 11 central facility/outlying clinic pairs (samples with matched lot numbers)
  • Author's conclusions:
    • There were no signs of instability; however, samples were early in their shelf life (mean age 8.6 months)
    • The one failure at the outlying clinic level could have been due to a measurement error


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: