Automated dissolution systems sampling technique

Many of the techniques described above, excipient compatibility, blend uniformity by HPLC dissolution, and content uniformity/assay by HPLC can be effectively automated by robotic sample preparation. Each of these techniques requires that the sample under study be dissolved in an appropriate solvent and fully extracted from any excipients. There are a number of commercially available products that have proven to be effective and robust in this sample preparation role. This robotic process can reduce both the analyst hours required to prepare a number of samples, and turnaround time on the sample analysis, since the robotic systems will operate unattended over night and on weekends. There is of course a cost to pay for laboratory automation. There is a significant capital cost, and then an ongoing maintenance cost for the continued operation of the system. Also it is critical that a specialist be available in-house to care for the system, develop the methods, and troubleshoot any issues with the system. The cost of the system and specialist must be weighed against the advantages of speed and lab capacity enhancement realized with a successful automation implementation. 

Headspace GLC analysis is a method used to monitor a vapour over a polymeric matrix. It is a very effective technique, but may require more time and effort than direct injection. This method can be performed manually, when a vial containing the monomer is heated, an equilibrium is established, for volatile compounds between the sample and the headspace above it. Because no dissolution step is required, sample viscosity problems and loss of response due to dilution are eliminated. Automated headspace analysis units are available from instrument manufacturers, as well as multiple extraction systems. Any analytically useful headspace method must obey Henry s law ... 

---