Examples of the invention include inhalation systems, breathing apparatuses, and methods for administering a solution by inhalation to a patient. Example breathing apparatuses described herein may be configured to minimize loss of the solution to the environment. Additionally or instead, example breathing apparatuses may be configured to recirculate exhaled solution to increase an amount of the solution available to a patient while minimizing exhausted solution. In some examples, breathing apparatuses may deliver nebulized platelet rich plasma (“PRP”).