A simple, rapid, sensitive and specific spectrophotometric method has been developed for the determination of two primary amines of pharmaceutical interest; dapsone and tranexamic acid. The method is based on condensation of the cited drugs with acetylacetone - formaldehyde mixture in acetic acid - sodium acetate buffer media by aid of heating at (97± 0.5°C) for a fixed time to yield a yellow colored condensation product ''dihydrolutidine derivative'' and possess a characteristic absorption maxima at 330 -345 nm. The variables affecting color development and the stability of the reaction product have been investigated and the conditions optimized. Beer's law is obeyed in the concentration range of 1 - 11 µg ml^-1 with molar absorpitivities ranging from 1.475x10⁴-2.015x10⁴ L.mol^-1cm^-1 and Sandell sensitivities of 8.11x10^-3-9.38x10^-3 µg cm^-2. The proposed spectrophotometric procedure was applied successfully for the determination of the cited drugs in some of their pharmaceutical formulations.