Several well known analytical tools viz. HPLC, GC, IR, UV-Vis, atomic absorption spectrophotometer etc. are available to a pharmaceutical analyst. However, to my mind, pharmaceutical analyst has still not utilized all analytical techniques science has offered to us. To name few, are Near Infra red- NIR, Raman spectroscopy and HPTLC.
With the process analytical technique- PAT, claiming importance in quality control departments of several established pharmaceutical companies especially in the US, one has to rethink on easy yet accurate ways of content measurement in pharmaceutical products. HPTLC is another such easy analytical technique that is precise, speedy and easy to work with but has not become very popular in the analytical field.
To elucidate the merits of HPTLC, without promoting any brand of the analytical equipments, I have mentioned herein few cases (published in serial order). This work was done during my postgraduate days wherein we attempted to study use of HPTLC in the analysis of assay of active pharmaceutical ingredients- API, formulations and from plasma samples of a bio-equivalence study.
This article attempts to depict merits of HPTLC in estimation of assay of API. Pseudoephedrine hydrochloride is a model drug for this study.
Pseudoephedrine hydrochloride, a stereoisomer of ephedrine belongs to the class of sympathetomimetic drugs 1. Its main clinical use being a nasal decongestant. It is employed alone or in combination with other agents.
Analytical methods reported for estimation of pseudoephedrine include thin layer chromatography [TLC], gas chromatography [GC] and high performance liquid chromatography . However, quantitative high performance thin layer chromatography [HPTLC] estimation for this drug has not been reported hitherto.
The GC and HPLC assay procedure although, possess good sensitivity are tedious. TLC on the other hand is easy but lacks the sensitivity and selectivity necessary in the analysis of pharmaceutics. HPTLC possess the advantages of being simple, rapid (since 10 –20 sample can be estimated on a single plate), and easy to operate giving rapid performance with high resolution. The method has widely been accepted for qualitative and quantitative evaluation of drugs belonging to various classes viz. vitamins, steroids, amino acidic , alkaloids ,
The objective of this study was (i) to develop HPTLC method for determination of pseudoephedrine and (ii) to apply the method to the quantitative estimation of pseudepherdine hydrochloride samples stored under stress conditions.
To be continued in Part 2 ...