This Phase 1 clinical trial investigates the pharmacokinetics and safety profile of single-dose inhaled RJ026 in healthy volunteers and patients with interstitial lung disease (ILD). The randomized, double-blind, dose-escalation study employs a parallel-group design with three inhaled dose cohorts (4mg, 8mg, and 12mg) and one oral comparator arm, enrolling a total of 42 patients (12 per inhaled group, 6 in oral group) and 42 healthy volunteers (12 per inhaled group, 6 in oral group). The trial features comprehensive pharmacokinetic sampling through 15 timed blood collections over 24 hours and bronchoalveolar lavage at specified intervals (1h, 6h, 12h, or 24h post-dose) to characterize both systemic and pulmonary drug exposure. The study incorporates rigorous safety monitoring including adverse event tracking, vital sign measurements, and laboratory assessments over a 7-day observation period following drug administration. Conducted at Shanghai Jiao Tong University's Ruijin Hospital over a 12-month period (July 2025-July 2026), this investigation aims to establish the foundational pharmacokinetic parameters and safety profile of RJ026 delivery in ILD patients while comparing pulmonary bioavailability against conventional oral administration.