Ampicillin capsules

No problem was seen in the initial quality of ampicillin capsules: 10 GMS samples were within specification limits (92.5-110%). This drug is not available at PHC level and turnover at hospitals was fast One (4%) of 28 facility samples was marginally below the lower assay limit (assay 92.4%) at age 28.5 months. This was the only sample which expended more than half the three year shelf-life.

The 11 paired samples showed no consistent loss of potency after a mean interval of 5.3 months. There were no signs of instability, but facility samples were in the early part of a three year shelf-life (mean age 8.6 months).

The single failure may be accounted for by a measurement error. A recent policy decision means that ampicillin capsules will no longer be supplied in Zimbabwe, amoxicillin capsules will be used instead.

Doxycycline capsules

This was a hospital-only drug supplied by a single manufacturer. One batch was received in GMS with more than half the shelf-life expended. Initial potency was within the wide specification limits (90-120% USP) with a mean assay of 102.1%, However, the sample size was small (only five GMS samples were tested). The 15 facility samples tended towards the upper limit of specifications: mean assay 110.1% with a mean age of 17.3 months. Two (13%) facility samples failed, but only one was below the lower limit (82.7%) at age 21.9 months; the other was above. 60% of facility samples had expended more than half of their shelf-life (two or three years). The results for five expired samples showed a lower mean assay (97.8%) at mean age 27.7 months.

There was no evidence of instability in five GMS/facility sample pairs after a mean interval of 10.1 months, but the sample size was small. The mean assay for both GMS and facility samples had wide confidence limits (plus or minus 5%) which made the interpretation of results difficult. A measurement error may be considered for the single low failure.

A policy decision to replace tetracycline capsules with doxycycline capsules at the PHC level will increase the volume of doxycycline used.