using a mortar and pestle. The powder was added in 200 mL of
n-hexane. The mixture was heated for 10 min with continuous
stirring. The cooled mixture was filtered through a Whattman
filter paper (No.1) and the filtrate evaporated to dryness in a hot
water bath to give ibuprofen crystals.
The crystals were packed into a capillary tube and tapped on
a hard surface to form a column at the bottom of the capillary
tube. The tube was inserted into a heating block of a Gallenkamp
melting point apparatus and already maintained at a temperature
of 70 C. The temperature of the heating block was raised at
0.5 C per min until the sample melts. The melting temperature
was recorded as the melting point. Triple determinations were
carried out in per brand.