Related Experiment Video
Updated: Feb 8, 2026

An In Vitro Dissolution Determination of Multi-Index Components in Tibetan Medicine Rhodiola Granules
Published on: November 4, 2022
Validated ion pair chromatographic method for simultaneous determination and in vitro dissolution studies of
Yomna A Salem1, Mohammed E A Hammouda2, Noha M Saleh3
1Department of Medicinal Chemistry, Faculty of Pharmacy, University of Mansoura, Mansoura, 35516, Egypt.
Abstract:
A rapid, and highly sensitive analytical method were developed for the simultaneous determination of indacaterol maleate (IND) and glycopyrronium bromide (GLY) in their inhaler capsules. Valid ion-pairing chromatographic (IPC) method was performed for separation of GLY in presence of IND using C18 column and mobile phase consisting of acetonitrile: acidified deionized water (60:40% v/v) containing 0.02% sodium dodecyl sulfate (SDS) adjusted to pH 3.0 using OPA (orthophosphoric acid) isocratically eluted at 2.0 mL/min. Quantitation was achieved with UV detection at 210 nm. Cyproheptadine was used as an internal standard. The retention times were 1.9 and 2.5 min for IND, and GLY, respectively. For the IPC method, the calibration graphs were linear in the range of 0.66-66.0 μg/mL for IND and 0.3-30.0 μg/mL for GLY. The proposed method are rapid, reproducible (R.S.D. <2.0%) and achieves satisfactory resolution between IND and GLY (resolution factor = 4.23). The mean recoveries of the analytes in their inhaler capsule were satisfactory. It was applied successfully to in vitro dissolution testing using Franz diffusion cell and extended to a content uniformity test consistent with the United States Pharmacopoeia (USP) guidelines and were found to be precise and accurate for the capsules studied with acceptance value of 4.53 and 1.39 for IND and GLY, respectively.
Related Concept Videos
In Vitro Drug Dissolution: Alternative Methods
Dosage Interval and Administration Route: Determination Methods
Chromatographic Methods: Terminology
Chromatographic Methods: Classification
Chromatographic techniques are typically named by...
Pore Transport and Ion-Pair Transport
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
Precipitation of Ions
The equation that describes the equilibrium between solid calcium carbonate and its solvated ions is:

