We can now compare the average loss of active ingredient for a hypothetical pattern of climatic conditions during shipment and storage in tropical climates, which could include 12 months at 30°C, one month at 40°C and one month at 25°C in the light (see Table 6).

From this table it can be seen that the short-term exposure to higher temperatures is much less harmful than the exposure to light which, for ergometrine and methylergometrine, results in 21-27% loss after one month. It is evident that longer exposure to light would result in further loss of potency. These results tally very well with the results of the field research (Table 2 and Annex 1) where 28% of all samples had a potency below 60% of the stated amount, with some samples measuring as low as 21 and 34%.

Table 6 Estimated loss of active ingredient of injectable oxytocics during transport and storage in tropical climates*

* Expressed as percentage of initial amount