The solubility and rate of dissolution of a poorly-soluble active principle are of importance when substances are destined for oral administration. Physical blends in wich drug and carrier are able to form particular compositions, such as a eutectic, may exibit an increased rate of dissolution. In this work the interactions lorazepam and PEG 6000, were examined, the particular thermal behaviour of lorazepam being taken into account. An eutectic was obtained and its composition was studied by means of differential scanning calorimetry, thermomicroscopy, infrared spectroscopy and X-ray methods.