DISSOLUTION STUDIES OF HEXAMETHYLMELAMINE

A study has been made of the dissolution rates of 'end' and 'side' fac es of single crystals of the anti-tumour drug hexamethylmelamine (HMM) . The results demonstrate preferential dissolution of the end faces. V arious features of the dissolution process show that it is surface-rea ction rather than diffusion controlled. Comparisons are made with resu lts from an earlier study of the growth of HMM crystals. It is conclud ed that geometrical features of the crystal packing of HMM molecules p lay a rate-determining role in the dissolution