Temperature control in high performance liquid chromatography proves formulation of active pharmaceutical ingredients, comparing two versions of a well known drug
Temperature programmed liquid chromatography (TPLC) specialist Selerity Technologies says it has shown that its Polaratherm total temperature controller and oven offer a proven method for the separation of active pharmaceutical ingredients.
Under experimental conditions, Selerity used temperature as the key parameter to successfully analyse two sources of sildenafil citrate, the active ingredient in Viagra, to determine actual levels of the ingredient and compare them with the stated formulation.
Since the launch of Viagra by Pfizer in 1998, several copycats have been produced by companies based in Belize. These have been made readily available via the internet.
In an experiment, Selerity compared a Viagra tablet with one of the offshore alternatives.
Both of these tablets claimed to contain 100mg of the active ingredient, sildenafil citrate.
Both extracts were analysed by high temperature liquid chromatography (HTLC) using a thermal gradient.
The results unequivocally indicate that the sildenafil citrate tablet purchased via the internet was significantly inferior than claimed, containing 20% less of the active ingredient than the original Viagra tablet.
Additionally, the analysis of the Viagra sample confirmed that it does contain the stated amount of active ingredient.
No degradation occurred when performing the analysis at elevated temperatures.
Not only does this application further highlight the benefits of TPLC but it can significantly assist laboratories with their quality control, says Selerity.
Selerity's Polaratherm programmable TPLC oven is ideal for such analyses.
The instrument is the first HPLC system to completely harness temperatures of up to 200C in both isothermal and temperature gradient modes without presenting any negative effects during the separation run.
Additionally, the Polaratherm incorporates a user friendly design, and can be easily integrated as a modular addition to an existing HPLC system to produce unparalleled results.
Selerity has recorded the detailed results of this experiment in a new application note (number 807), available on its website.
