The reproduction and accuracy of dosing depends on the characteristics of the filler, the filling method and the type of filling machine. Active substances for filling into solid gelatin capsules must meet the following requirements: the contents must be released from the capsule, providing high bioavailability; when using automatic filling machines, active substances must have certain physico-chemical and technological properties, such as: certain particle size and shape; the same particle size; mixing homogeneity; flowability (fluidity); moisture content; ability to form compactly under pressure. To fill solid gelatin capsules, machines of various companies are used, differing in performance, dosing accuracy and the structure of the dispenser.