Results and Discussion:
Mass, IR spectral data and DSC thermo gram indicated that the pseudoephedrine test sample had high purity and compared well with the reference standard.
Under the chromatographic conditions described, the migration distance obtained in the case of both the reference as well as the test samples of pseudoephedrine hydrochloride was 34.0 mm (Rt – 0.41). the reference standard sample showed a single band. The test for selectivity employing mixture of pseudoephedrine HCl and phenylephrine showed sharp separation of HPTLC plate in the solvent system containing formic acid as mentioned earlier and compared well with the respective reference standard. The migration distance of pseudoephedrine HCl and phenylephrine were 34.0 mm (Rt – 0.41). and 51.0 mm (Rt – 0.62). respectively.
Observation on the limits of detection and quantification, selectivity, linear range and ruggedness of the proposed method were as follows-
Limit of detection (μg) 5
Limit of quantification (μg) 10
Linear range (μg), regression coefficient, r= 0.999 35-140
Sensitivity (units) 11.2
Ruggedness (%CV) between analysts 1.224
Ruggedness (%CV) between laboratories 2.32
Comparing the accuracies (%CV calculated over the linear range) of the HPLC and HPTLC method, It was found that the accuracy of the former was 1.362 units, while that of the latter was 3.002 units.
Application to stability studies-
The results of the stability studies indicated that there was probably no interference of degradation products during the assay. The degradation products however, were not identified since the reference standards for the same were not available.
A simple, selective and rugged HPTLC method has been developed and validated for determining pseudoephedrine HCl powder. The proposed method is comparable to the HPLC method (reported earlier in the literature). The HPTLC method can be applied for studying the stability of the pseudoephedrine HCl and sulphate samples stored under stress conditions of temperature and humidity. The method further needs to be tried for the analysis of pseudoephedrine in solid and liquid dosage forms.