Nebulizer systems, apparatus, and methods are disclosed. The apparatus includes a body, a breathing gas inlet and outlet, and a barrier. The body is sized to be positioned within an adaptor of the nebulizer system. The breathing gas inlet and the breathing gas outlet are at opposite ends of the body. The barrier is coupled to the body. A plurality of holes are formed in the barrier. The plurality of holes open in a direction orthogonal to the breathing gas inlet. The system employs the apparatus in conjunction with a nebulizer and an adaptor. The method includes generating an aerosolized medicament, providing the aerosolized medicament to the adaptor, passing the aerosolized medicament through the barrier of the apparatus, providing a breathing gas to the apparatus, and flowing the aerosolized medicament and the breathing gas through the breathing gas outlet of the apparatus.