Motivation for the study and guiding principles for the study design

There was a keen interest to audit the quality of essential drugs in the country, and specifically at the level of the end user, Zimbabwe has a large local pharmaceutical industry, offering the possibility of examining the quality of drugs without considering the effects of international transport. Any quality problems identified at the level of the end user would not differentiate between problems of instability related to low initial quality, exposure to adverse climatic conditions within the distribution system or storage at facility level, A longitudinal study was therefore needed.

The first longitudinal study in Sudan was "a departure from the ideal" as it replicated the real circumstances by procuring a single consignment of all study drugs from known manufacturers of high quality drugs in Sweden, This was logistically more feasible and facilitated interpretation of outcome. The foremost objective for the Zimbabwe study was to investigate the actual drugs available and used in the public sector health care system in Zimbabwe, This implied at the outset that research questions may not be answered clearly and conclusively on all of the drugs included for study. Another priority was that implementation of the study should improve the capability, through the experience gained/to continue some form of quality assurance activity after completion of the study.

Pharmaceutical sector in Zimbabwe

In Zimbabwe drug registration is overseen by the Medicines Control Council, a drug regulatory body empowered by an Act of Parliament. This drug registration system is computerized and effectively used, A drug control laboratory with comprehensive testing facilities is housed on the same premises. At the time of the study, the private sector was comprised of six local manufacturers, one wholesaler and approximately 200 retail pharmacy outlets.

At the time of the study, all non-profit health institutions (including missions and local/urban authorities) obtained their medical supplies from the Government Medical Stores (CMS). CMS tendered for drugs centrally. Manufacturers did not routinely supply batch certificates, although the local manufacturers assured that they could always be supplied on request. Manufacturers or suppliers delivered drugs to two central medical stores, one in Harare and one in Bulawayo. Three provincial medical stores drew supplies from Harare or Bulawayo and distributed them within their province. The remaining five provinces in Zimbabwe were supplied directly from the central medical stores. CMS has its own transport but also uses commercial transporters and the national railways. The delivery system from provincial medical stores is relatively fast and has good coverage, although supplies may remain in a district "in transit" before delivery to health centres. Harare and Bulawayo used their own trucks in a very limited catchment area, but contracted transport was used for the major part of supplies. Transport by rail represented the longest transit and storage times.