Learning Centre

welcome image
Click here for posts on new drug development
Click here for posts on generic drug development
ALL Background Analysis Dissolution Filters Biorelevant media NEW!
NEW!
What is filter compatibility and why is it so important?
Tip Image
There are two aspects of filter compatibility that the dissolution scientist should consider...
Sample requirements for a drug filter adsorption study
Tip Image
To conduct a drug filter adsorption study, typically, a sample representing around 10% to 20% of drug release from the immediate-release dosage form in the dissolution vessel is needed.
What is 'specificity'?
Tip Image
Specificity is an integral part of analytical method validation and must be performed by carrying out multiple injections to eliminate potential errors that can occur during experimental sequence.
What is 'precision'?
Tip Image
The degree of deviation between a set of measurements obtained from multiple analysis of the same homogenous sample under the specified conditions expresses the precision of an analytical method.
Why are specificity and precision required with biorelevant media?
Tip Image
Biorelevant dissolution media contain natural surfactants which can affect chromatographic properties leading to erroneous analytical results.
NEW!
When is a filter adsorption study necessary?
Tip Image
Filter adsorption studies should always be conducted before dissolution studies are carried out when a) a new drug is being tested or b) a different biorelevant medium is being used.
NEW!
Key requirements for filters used in biorelevant dissolution testing
Tip Image
We recommend the use of glass filters with pre-filters built-in. These filters have excellent efficiency in removing particles and do not leach substances into the biorelevant media.
When are specificity and precision required when testing drugs in biorelevant media using HPLC??
Tip Image
Specificity and precision when analysing drugs in biorelevant media by HPLC
Checking interference by injecting the dosage form in biorelevant medium
Tip Image
Interference of non-drug peaks (originating for example from excipients) should also be evaluated via specificity and precision using a sample which contains the dosage form.
How many HPLC injections are needed when carrying out specificity and precision?
Tip Image
For specificity and precision tests, it is recommended to carry out a similar number of injections that cover the number of samples that will be analysed by HPLC.
NEW!
Two-stage biorelevant dissolution
Tip Image
This experiment simulates the in vivo process when a drug product is transferred from the fasted stomach to the fasted intestine.
What to do if the retention time of a drug is reduced during HPLC analysis
Tip Image
Reduced retention time during HPLC analysis
Which factors can increase the retention time of an analyte during HPLC analysis
Tip Image
Which factors can increase the retention time of an analyte during HPLC analysis
NEW!
How to apply a washing cycle when running an HPLC sequence
Tip Image
How to apply a washing cycle when running an HPLC sequence
Which ingredients are in FeSSIF-V2 Powder?
Tip Image
This post describes the ingredients in this fed state biorelevant intestinal medium and its preparation.
Which ingredients are in FaSSIF-V2 Powder?
Tip Image
Which ingredients are in FaSSIF-V2 Powder?
NEW!
Signs of column deterioration
Tip Image
Explains what the common indicators of HPLC column deterioration look like
NEW!
How to store HPLC columns after using Biorelevant Media
Tip Image
How to store HPLC columns in the short, mid- and long term after using Biorelevant Media
NEW!
Coning of immediate release drug products in a USP 2
Tip Image
Coning of immediate release drug products is a problem
NEW!
What are the signs of coning
Tip Image
Signs and examples of coning in a USP 2 dissolution vessel
NEW!
PEAK (Apex) dissolution vessels
Tip Image
This post explains what PEAK (Apex) vessels
NEW!
What are ghost peaks and why do they occur?
Tip Image
This post describes potential causes of ghost peaks when analysing a drug in biorelevant medium
NEW!
What is supersaturation of a drug substance?
Tip Image
This post explains supersaturation of a drug substance
NEW!
What is equilibrium solubility of a drug?
Tip Image
This post explains equilibrium solubility of a drug substance in a test medium
NEW!
USP <1236>: Solubility Measurements Chapter
Tip Image
This post summarises USP Chapter <1236>