Background:
The main goal of process-related substances investigations is to understand how impurities
should be controlled during the synthetic or purification process to produce a high quality drug substance. The
simultaneous determination of related substances is very important factor in the quality control of API and pharmaceutical
dosage forms.
Methods:
A new HPLC method was developed for simultaneous analysis of Ipratropium bromide and its seven related
substances. The separation was performed on a waters HPLC ZORBAX Eclipse XDB- C8 column (150 × 4.6 mm, 3.5
μm). The gradient method used mobile phases containing methanol, acetonitrile, trifluoroacetic acid (TFA), water: A:
(methanol, acetonitrile, TFA, 500:500:0.3 v/v/v) and B (0.3% TFA in water v/v). The gradient elution conditions were as
follows: 0-32.0 min, linear from 10% A to 35% A; 32.0-36.0 min isocratic 35% A; 36.0-42.0 min linear from 35% to
10%A. The wavelength by UV detector was 220 nm and the flow rate was 1.2 mL/min. The injection volume of sample
was 20 μL and the column temperature was 30 ºC. The proposed RP-HPLC method was applied for the determination
seven related substances.
Results:
All standard curves obtained exhibited good linear regression (r > 0.9939) within the tested range. The average
recovery rates were in the range of 98.2-102.0% and RSD was less than 2.9% (n = 3). The process-related impurities were
not observed in different batches (<0.025% purity).
Conclusion:
The method was applied to determine 7 process-related substances in ipratropium bromide and proved to be
robust, linear, repeatable, sensitive, selective and easy to perform. The results are valuable for quality control in the
manufacturing of ipratropium bromide.
