RESUMO
Pulmonary arterial hypertension (PAH) is a life-threatening disease characterised by elevated pulmonary pressure, right ventricular failure (RVF) and ultimately death. Aggressive treatment of RVF is considered an important therapeutic strategy to treat PAH. Previous studies have indicated that betaine may be may a promising therapeutic approach for PAH-induced RVF. Therefore, in this study, betaine solution for injection was prepared and characterised using various techniques. The therapeutic efficacy of three different methods of administration (intragastric, nebulised inhalation and intravenous injection) were comprehensively evaluated in terms of pharmacokinetics, tissue distribution and pharmacodynamics. The pharmacokinetic results demonstrated that betaine injection administered via nebulised inhalation significantly prolonged betaine's half-life and increased its internal circulation time compared to the intragastric and intravenous routes. Biodistribution experiments verified that the betaine formulation accumulated in the lung tissue when administered via inhalation. The results of the pharmacodynamic analysis further confirmed that right ventricular systolic pressure, mean pulmonary artery pressure and right ventricular hypertrophy index increased in the model group and that inhaled betaine suppressed these pathological changes to a level comparable to those observed in the control group. Taken together, these results indicate that betaine administered by inhalation is a promising strategy for the treatment of PAH-induced RVF.