Learning Centre

How to analyse your drug in Biorelevant Media
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After drug separation, the medium (containing dissolved drug) is best analysed by HPLC. HPLC avoids potential interference of the media and can identify possible drug instability
HPLC Parameters using FaSSIF-V2
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Comparing HPLC profiles of FaSSIF-V2 made using Buffer Concentrate versus FaSSIF-V2 made using buffer from scratch
What is a diluent?
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A diluent is a solvent which is added to standard solutions of a drug substance...
Why include Biorelevant Medium in working standard solutions (WSS)
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It is important to include Biorelevant Medium when diluting secondary standard solutions (SSS) as it keeps the matrix...
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Why Biorelevant Dissolution samples should be diluted for HPLC analysis
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Without dilution, drugs which are poorly water soluble may precipitate from biorelevant medium at room temperature after sampling.
How to examine compatibility and dilution ratio of diluent with Biorelevant Media
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Before HPLC analysis of any biorelevant dissolution sample containing drug, it is important to have identified a compatible diluent for the biorelevant media that will be used.
How to calculate the theoretical maximum drug concentration for Primary Standard Solution (PSS)
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Before making the PSS, calculate the theoretical maximum drug concentration required for analysis...
How to dilute and prepare standard solutions
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There are three types of standard solutions that need to be prepared when analysing dissolution samples...
Which dilution ratio to select for HPLC analysis
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A suitable diluent ratio should not only keep the sample chemically and physically stable but should also allow the drug to be detected accurately and precisely by HPLC.
How to prepare the working drug solution containing dosage form (e.g. drug and excipients) with biorelevant medium to check interference
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Three steps are required to prepare the working drug solution containing dosage form...
Which solutions are required to check for interference
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The following solutions should be tested to check for interference...
How to dilute your secondary standard solution (SSS) and dissolution samples with 1:10 dilution ratio whilst keeping the same matrix
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The dilution of standard solutions containing biorelevant medium is slightly different from the biorelevant dissolution sample...
Selecting the drug concentration range of linearity working standard solutions
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The linearity of an analytical method enables (over the range of dissolution concentration) generation of test results which are directly proportional to the concentration of drug substance in the dissolution sample.
What is 'specificity'?
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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'?
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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?
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Biorelevant dissolution media contain natural surfactants which can affect chromatographic properties leading to erroneous analytical results.
When are specificity and precision required when testing drugs in biorelevant media using HPLC??
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Specificity and precision when analysing drugs in biorelevant media by HPLC
Checking interference by injecting the dosage form in biorelevant medium
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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?
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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.
What to do if the retention time of a drug is reduced during HPLC analysis
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Reduced retention time during HPLC analysis
Which factors can increase the retention time of an analyte during HPLC analysis
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Which factors can increase the retention time of an analyte during HPLC analysis
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How to apply a washing cycle when running an HPLC sequence
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How to apply a washing cycle when running an HPLC sequence