Related Experiment Video
Updated: Aug 18, 2026

Dry Powder and Nebulized Aerosol Inhalation of Pharmaceuticals Delivered to Mice Using a Nose-only Exposure System
Published on: April 6, 2017
Compatibility and osmolality of inhaled N-acetylcysteine nebulizing solution with fenoterol and ipratropium
Tzung-Yi Lee1, Chi-Ming Chen, Chun-Nin Lee
1Department of Pharmacy, Mackay Memorial Hospital (MMH), Taipei, Taiwan.
Purpose:
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.
Conclusion:
NAC and ipratropium were stable in nebulizing solution within one hour of mixing. NAC and fenoterol were compatible for at least seven hours.
Related Concept Videos
Inhaled Medications
Cholinergic Antagonists: Pharmacokinetics
Upper Respiratory Drugs: Antitussives, Expectorants, and Mucolytics
Antitussives include codeine, dextromethorphan (Robitussin), and benzonatate (Tessalon). Codeine and dextromethorphan exert their effects centrally by suppressing the cough reflex center in the medulla. Benzonatate operates peripherally within the respiratory tract by anesthetizing...
Antiasthma Drugs: Muscarinic Receptor Antagonists
Antimuscarinic agents compete with ACh for the same binding site on the muscarinic receptors. By binding to these receptors, they inhibit the downstream effects of ACh and block the parasympathetic...
Acute Respiratory Failure-V
Ensure that patients are monitored continuously for their response to therapy, including changes in...
Antiasthma Drugs: Inhaled Corticosteroids and Glucocorticoids
ICS work through a multifaceted mechanism of action. They suppress the inflammatory response caused by the proliferation of TH cells. They also reduce the transcription of the IL-2 gene, which is involved in the...