Metrohm has announced its Titrando is suitable for analysing the chemical make-up of aspirin tablets.
Acetylsalicylic acid (ASA [aspirin]) is combined with sodium bicarbonate and citric acid in aspirin tablets to relieve pain.
The aspirin in this medicine helps prevent dangerous blood clots from forming, but can also increase the chance of serious bleeding in some people.
This ratio is critical and slight increases or decreases of one or more components can have catastrophic affects.
The aspirin level is typically determined using UV.
The sodium bicarbonate is determined by a non-aqueous titrimetric method using perchloric acid as the titrant and glacial acetic acid as the solvent.
The basic unit of a Metrohm Titrando system consists of a titrator with one measuring interface that can be expanded.
The Titrando system is entirely oriented towards quality management according to GLP.
As the dosing elements play a crucial role in titration, the dosing units have a data chip from which the Titrando automatically reads all the data that it needs for the titration.
An 809 Titrando in conjunction with the 800 Dosino dosing system can titrate sodium bicarbonate to the CFR 21 Part 11 pharmaceutical standard.
All of this is controlled using the full colour 840 Touch Control.
The titration takes place in a completely sealed vessel, where the glacial acetic acid is accurately added using a second Dosino.
After the titration, the contents of the titrated solution are aspirated to waste using the second bidirectional port of the Dosino.
A solvent blank is performed, which is automatically stored by the Titrando and then used in the subsequent calculation of the sodium bicarbonate concentration.
The Metrosensor Solvotrode is used as the indicator electrode.
This is a combined pH glass electrode with easy-to-clean diaphragm, which is designed specifically for such demanding titrations.
Whole tablets can also be analysed by smashing up the tablet in situ using an in-built homogeniser.
The 789 Robotic Sample Processor XL automates the sample preparation.
In this case the homogeniser is mounted on a swing head with robotic arm, which allows the processing of large series of samples in multi-row racks.
