Compatibility and osmolality of inhaled N-acetylcysteine nebulizing solution with fenoterol and ipratropium.
OBJECTIVE
The compatibility, pH, and osmolality of N-acetylcysteine (NAC) nebulizing solution in the presence of ipratropium bromide or fenoterol hydrobromide were studied.


METHODS
Portions (400 microL) of each mixture were sampled immediately upon mixing and one, two, three, four, five, six, and seven hours after mixing and assayed by high-performance liquid chromatography. Osmolality was measured by sampling 100 microL from the filling cup at a five-minute interval during nebulization and by the freezing-point-depression method.


RESULTS
Adding NAC solution to fenoterol solution raised the pH from 3.20 to 7.90 and the osmolality to a mean +/- S.D. of 1400.67 +/- 4.51 mOsm/kg. Fenoterol concentrations decreased to 93.71% and NAC concentrations to 92.54% of initial concentrations after seven hours. Mixing ipratropium with NAC solution raised the pH from 3.74 to 7.95 and the osmolality to a mean +/- S.D. of 1413 +/- 11.79 mOsm/kg. The initial ipratropium concentration declined 7.39% and 10.91% one and two hours after mixing with NAC solution, respectively.


CONCLUSIONS
NAC and ipratropium were stable in nebulizing solution within one hour of mixing. NAC and fenoterol were compatible for at least seven hours.
Lee
Tzung-Yi
TY
Department of Pharmacy, Mackay Memorial Hospital (MMH), Taipei, Taiwan.
Chen
Chi-Ming
CM
Lee
Chun-Nin
CN
Chiang
Yi-Chun
YC
Chen
Hsiang-Yin
HY
D000111:Acetylcysteine / Q000008:administration & dosage*; D000280:Administration, Inhalation; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D005280:Fenoterol / Q000008:administration & dosage*; D006863:Hydrogen-Ion Concentration; D009241:Ipratropium / Q000008:administration & dosage*; D013058:Mass Spectrometry; D009330:Nebulizers and Vaporizers; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D012996:Solutions / Q000592:standards*
D000318:Adrenergic beta-Agonists; D001993:Bronchodilator Agents; D012996:Solutions; D005280:Fenoterol; D009241:Ipratropium; D000111:Acetylcysteine