Pharmacokinetics of ketoprofen nanosystem was studied in outbred rats after single endotracheal administration. Ketoprofen was analyzed in blood serum and tissues by HPLC with UV detection. After endotracheal administration of the nanosystem, ketoprofen rapidly appears in systemic blood flow and its concentration in blood serum reaches maximum after 15 min. The maximum drug concentration in tissues was observed near the site of introduction, namely, in lungs Ketoprofen showed moderate penetration in tissues with high vascularization, and weak penetration in tissues with moderate vascularization. After endotracheal administration of the nanosystem, only small amount of ketoprofen overcomes the blood brain barrier.