Simultaneous detection and quantification of bronchodilators in pure form and from in-vitro drug release of a novel combinational formulation

The analytical method was developed and validated for the quantification of salbutamol sulfate (SS) and ipratropiumbromide (IPB) in accordance with the International Council for Harmonization guidelines in its pure form. Thechromatographic partition was completed utilizing a blend of acetonitrile:phosphate buffer (30:70 v/v) with the pHscale adjusted to 3.0 using o-phosphoric acid at a flow rate of 1 ml/minute in Luna C-18(2)(150 × 4.6 mm i.d., 5 μm)column. The wavelength for detection was fixed at 212 nm. The SS and IPB showed a standard linearity curve in therange of 2–12 µg/ml, with retention time at 2.4 and 3.8 minutes, respectively. The developed method was reported tobe specific, linear (r2 ≥ 0.999), precise at intraday and interday levels (% relative standard deviation < 2.0%), accurate(% recovery: 96.02%–103.62%), and robust. The limit of detection and limit of quantification for SS was found to be0.42 and 1.26 µg/ml, while that of IPB was 0.44 and 1.34 µg/ml, respectively. Additionally, the developed method waseffectively applied in quantifying SS and IPB from its pure, commercial, and in-house prepared transdermal system tounderstanding the in-vitro drug release pattern from patches.