Microencapsulation of highly water soluble pharmaceutical substances (solubility more than 1g/ml), especially if high drug loading is required (more than 50%) is a big challenge. Biodegradable polylactide as coating material and polyvinyl alcohol as surfactant were found suitable for this purpose. Active substance was microencapsulated using slightly modified waterin- oil-in-water technique which involves dissolving of the drug in the water and polymer in methylene chloride and forming an emulsion in water using a surfactant. Procedure of microencapsulation was followed by filtration and drying of product obtained. Not only the developed method enables microencapsulation of highly water soluble pharmaceuticals, but it also predicts properties of products obtained. Microencapsulation technique developed allows encapsulation of highly water soluble pharmaceutical with drug load up to 80%, and encapsulation efficiency up to 65%. During the study such parameters as emulsification time, volume of outer water phase and amount of active ingredient in inner water phase on microencapsulation process and product properties were investigated.