A method for monitoring, documenting and assisting with the manual preparation of medications supplied from a manufacturer as a liquid or as a medication requiring reconstitution and preparing a volume of the liquid or reconstituted medication for administration to a patient according to instructions contained in a prescription, said method comprising: a) using at least one digital camera to provide constant surveillance of the preparation process carried out on a work surface, wherein at least a portion of said work surface is inclined at an angle with a horizontal plane; b) providing software adapted to perform image processing of images acquired by said at least one digital camera and to compare, in real time, data extracted from the processed images to information relative to one or more of a patient, drug components and composition of said medication, and non-drug items needed in the preparation, wherein said data is automatically or manually retrieved from various sources; c) providing dedicated software algorithms that are adapted to act as an interactive assistant guiding and/or supervising a producer through each step of a specific preparation process; d) using said interactive assistant to guide or supervise the producer to fill a syringe at different stages of the preparation process with the correct volume of either liquid medication, with diluent used to reconstitute a medication, or with reconstituted medication; e) placing a syringe filled with liquid on said inclined portion of said work surface with its tip up and its longitudinal axis aligned with the slope of said surface to determine whether bubbles are present in the liquid in said syringe; and f) using images acquired by said at least one digital camera to determine whether bubbles are present in the liquid in said syringe, to measure the volume of said bubbles, and to measure the volume of liquid in said syringe, then the algorithms will approve the volume or warn for bubble existence and calculate the actual liquid volume by subtracting the bubble volume from the liquid volume. a) using at least one digital camera to provide constant surveillance of the preparation process carried out on a work surface, wherein at least a portion of said work surface is inclined at an angle with a horizontal plane; b) providing software adapted to perform image processing of images acquired by said at least one digital camera and to compare, in real time, data extracted from the processed images to information relative to one or more of a patient, drug components and composition of said medication, and non-drug items needed in the preparation, wherein said data is automatically or manually retrieved from various sources; c) providing dedicated software algorithms that are adapted to act as an interactive assistant guiding and/or supervising a producer through each step of a specific preparation process; d) using said interactive assistant to guide or supervise the producer to fill a syringe at different stages of the preparation process with the correct volume of either liquid medication, with diluent used to reconstitute a medication, or with reconstituted medication; e) placing a syringe filled with liquid on said inclined portion of said work surface with its tip up and its longitudinal axis aligned with the slope of said surface to determine whether bubbles are present in the liquid in said syringe; and f) using images acquired by said at least one digital camera to determine whether bubbles are present in the liquid in said syringe, to measure the volume of said bubbles, and to measure the volume of liquid in said syringe, then the algorithms will approve the volume or warn for bubble existence and calculate the actual liquid volume by subtracting the bubble volume from the liquid volume.