In each country, survey sites were selected in consultation with the local counterpart. The following criteria were considered in the selection of survey sites: the size and population, commercial importance and the existence of a referral health care unit. In each survey site, drug outlets were selected randomly. Samples were collected on payment and the operations were carried out under cover by people recruited locally so that the vendors had no indication as to the purposes of the purchases.

In the collection of samples, care was taken to purchase adequate quantities from the same batch of the product. In the case of solid oral dosage form preparations (capsules/tablets), a minimum of 100 unit doses were purchased. In the case of oral liquid dosage forms, small volume parenterals, and dry powders for injection, 7 to 10 bottles, 30 ampoules and 20 vials respectively were bought.

In Myanmar two types of samples were collected. The first group (Table 1) consisted of 215 samples of the 10 pharmaceutical products. They were purchased from public and private drug outlets and market places in the cities of Mandalay, Monywa, Sittway and Yangon. All the samples were contained in their original primary containers and had shelf-lives ranging from one to three years.

Table 1: Samples of products collected from four survey sites in Myanmar, shown by country of manufacture

The second group of samples (Table 2), numbering 23, were purchased from market places in Yangon. These samples were taken from products that had been removed from their original primary containers and repacked in polyethylene plastic bags by the vendors. The products were sold without labels. The vendors claimed the preparations to be amoxicillin capsules, ampicillin capsules, chloramphenicol capsules, tetracycline capsules, and vitamin B1 and vitamin B complex tablets. They were tested to see whether they contained the active ingredients claimed by the vendors.

Table 2: Unlabelled samples collected from Yangon markets

In Viet Nam samples were collected from Hanoi, Ho Chi Minh City, Ha Long and Hai Hung. A total of 288 drug samples (Table 3), imported as well as locally manufactured, were purchased from public and private pharmacies and market places.

Table 3: Samples of products collected from four survey sites in Viet Nam, shown by place of manufacture

In both countries, information about each sample, including the name of the product, the dosage form and the batch number, was recorded on a pre-prepared form (Annex 1). Each sample was then divided into three portions. The first portion served as control, the second portion was submitted for laboratory testing and the third portion was used for those drugs sent for further investigation to their country of origin.

Samples to be tested were removed from their primary containers and repacked in high-density polyethylene bottles, labelled, coded and sent to the WHO collaborating laboratory in Thailand for testing.

Additional information about each drug sample was obtained from the DRAs of Myanmar and Viet Nam through the questionnaire shown in Annex 3. Products confirmed as registered and genuine by the responsible staff of the DRAs were separated from those not registered. The samples of unregistered products were sent to the DRAs of the countries of manufacture. The DRAs were requested to indicate whether the products were manufactured in their countries, whether the manufacturers were licensed, whether the products were authorized/registered for sale in the countries, and whether they were genuine.