FIELD : medicine.SUBSTANCE : invention relates to medicine, in particular to a pharmaceutical composition for maintaining a stable suspension or dispersion of a drug with poor water solubility, as well as a pharmaceutical composition packaged in a stick pack. Above proposed pharmaceutical composition contains polystyrene sulfonate as a drug with poor water solubility, methylcellulose, and also additionally includes a natural polysaccharide which is a combination of xanthan gum and locust bean gum.EFFECT : implementation of the invention allows to obtain a composition of a drug with poor water solubility in the form of a suspension or dispersion with increased stability.4 cl, 1 tbl, 6 ex