Author raised problems and showed through research data some simple possibilities to achieve controlled release drug liberation. The dosage form developed during drug formulation work may influence the biological effects exerted by the active ingredients and therefore may alter the therapeutic efficacy, too. The dosage from itself includes all the chemical properties of active ingredients (salt-, ester form, polar-apolar material etc.), the physical state (crystal, amorphous, polymorphous, particle size, surface area, solvated state etc.), the value of stability and the parameters of auxiliary materials and manufacturing processes. The aim of formulation -among others-is to achieve the optimal liberation and bioavailability of drugs. The article reviews the possibilities through examples (theophylline, nitrofurantoin, phenacetin, antacids) how to make production prescriptions with high reproducibility used for the preparation of prolonged action systems with controlled release drug liberation.