Abstract: The ADME of a drug involves its transport across cell membranes. This process is essential and influenced by the characteristics of the drug, especially its molecular size and shape, solubility at the site of its absorption, relative lipid solubility, etc. Over the last ten years, the number of poorly soluble drugs has steadily increased. One of the progressive ways for increasing bioavaibility is a technique of nanoparticles preparation, which allows many drugs to reach the site of action. Candesartan cilexetil (BCS class II) was chosen as a model compound. Twenty samples were prepared by precipitation with various surface-active excipients. All the prepared samples were analyzed by means of photon cross-correlation sensor Nanophox. Eighteen samples contained nanoparticles smaller than 200 nm. Relationships between solvents and used excipients and their amount are discussed.