The samples (Table 1) studied were purchased from pharmacies
across the city centre. Brands available in each pharmacy
were selected to make up the ten brands studied. A brand already
selected from one pharmacy was no longer considered in any
other one. Pure ibuprofen powder was gratefully received as a
gift sample from Edo Pharmaceuticals Nigeria Limited, Benin
City, Nigeria. All other reagents were of analytical grade and
water was double distilled.