Frequently Asked Questions About the Apex (Peak) Vessel
One of the areas of the most focus in the dissolution world right now is the Apex vessel, which was formerly called the Peak vessel. With all of this new attention, I thought it would be good to answer some of the most common customers I get from scientists about this unique vessel.
When should I use the Apex vessel?
The Apex vessel can be a good option for formulations that have significant coning issues. A cone alone isn’t a bad thing, but if you find that you have a relatively rigid cone and are getting lower results then the Apex vessel can be a good option to explore. You may be able to show better robustness and discrimination of a dissolution method at lower RPM speed compared to higher RPMs in a standard vessel.
How do I justify using the Apex vessel?
The Apex vessel is not a first-line choice for a dissolution method. Generally, you will need to demonstrate failure in dissolution method development with Apparatus 1 and 2 under normal RPM and media conditions first. If you have a product which isn’t suitable under either condition, then Apex vessels can be an option to explore next.
Is the Apex vessel compendial in the USP?
Not yet. But the Apex vessel is mentioned in USP <1092> now, and I would expect we see some further reference to it in USP <1092> or maybe even USP <711> in the next couple years as an alternate approach.
Have regulatory agencies approved methods with the Apex vessels?
Yes. You can find two methods each in the USP and FDA Dissolution Method Databases. There is also a fifth approved method outside of the US.
How do I use an Apex vessel on my system?
An Apex vessel is just another vessel choice on the system. You can easily swap your standard vessels with these and set the height appropriately. There is a spacer tool for this. Qualification and standardization of these vessels is one of the key areas being explored in those USP stimuli articles I linked above.
If I have a failing dissolution method, can I switch the vessels?
No. If you have an established and approved dissolution method – this is a significant change. Most likely, you need to perform a failure investigation to determine the root cause of the issue you’re having. If you have a product now failing dissolution repeatably where it hasn’t before, this might be indicating a formulation problem that needs to be fixed. We can never just change an approved dissolution method to make it pass.
Read also:
- Comparative Dissolution Profile Guideline
- Understanding the Q Value in Dissolution Testing
- Factors Affecting Dissolution of Pharmaceutical Products
Resource Person: Ken Boda
