Abstract
The main objective of this work was to use the differential scanning calorimetry in conjunction with optical microscopy to study the compatibility of ibuprofen with lactose and polyvinylpyrrolidone and to provide an explanation(s) for the reduction in the dissolution rate observed from the ternary interactive mixture containing ibuprofen in previous study. Mixtures containing micronized ibuprofen-fine lactose 90:10 and 20:80 w/w showed a decrease in the melting peak of lactose by 14.33 and 10.94 A degrees C, respectively. The addition of 5 % fine lactose to the binary system has the highest effect on the melting point of ibuprofen by reducing the melting peak of ibuprofen from 76.2 to 73.72 A degrees C. Microphotographs obtained from optical microscopy for ibuprofen, binary and ternary interactive mixtures showed that agglomeration of ibuprofen was formed in the binary and ternary interactive mixtures. Lactose and polyvinylpyrrolidone must be avoided in the preparation of ternary interactive mixtures of ibuprofen to prevent drug-excipient interaction.