Evaluation of the Inhalation Safety of Domestic Pharmaceutical Metered-dose Inhalers Accessories Hydrofluoroalkane-134a

OBJECTIVE  To evaluate the inhalation safety of domestic pharmaceutical metered-dose inhalers accessories hydrofluoroalkane(HFA)-134a.

METHODS  The 21 d repeat dose inhalation toxicity study and Hartley guinea pig active systemic anaphylaxis for samples from two major domestic manufacturers were tested.

RESULTS  SD rats were exposed nose-only separately to the samples from two major domestic manufacturers at the concentration of (2 140±58)g·m^–3 and (2 129±59)g·m^–3 respectively for 21 consecutive days(2 h each day), there were statistically significant differences in the following indicators: some indicators of hematology such as neutrophil count, basophil, basophil ratio, monocyte ratio, hematocrit and platelet count, some indicators of blood biochemistry such as albumin content, total bilirubin content, chloride ion and potassium ion, some indicators of urine such as nitrite, leukocytes, urobilinogen, protein and bilirubin, organ weight and coefficients of kidney, thymus, heart, pituitary and lung. No systemic sensitization reaction were observed in guinea pigs.

CONCLUSION  The domestic pharmaceutical HFA-134a have certain toxic effects on some organs, blood and urine biochemical indicators of SD rats exposed to 250 times of the clinical maximum dose for continuously 21 d, however, further research is need to access whether inhalation is safe in normal clinical dose.