A system and method allows for processing of two groups of medical devices, both groups being alternatingly spray coated within the same enclosure. The two groups repeatedly move back and forth between a spray area and a drying area which is isolated from the spray area. One group moves into the spray area as the other group moves out and into the drying area. Thereafter, the group in the spray area moves out and into the drying area and the other group moves back into the spraying area for a second coating. The alternating process may be repeated any number of times. The spray area may be located inside a sealed spray isolator enclosure and surrounded by gas discharge nozzles.