A pharmaceutical reference standard is a highly characterized material suitable to test the identity, strength, quality and purity of substances for pharmaceutical use and medicinal products
Standards
A working standard (i.e., in-house or secondary standard) is a standard that is qualified against and used instead of the reference standard
Primary and Secondary standards
Primary and secondary standards are used in the pharmaceutical laboratory to determine the purity and quality of the drug substance and drug product. so it is important to have the right standards with right quality in place in the laboratory. To achieve this qualification laboratory should know and follow best practices. To know best practices to be followed during the qualification please click the link know more.
Reference standard Vs Secondary (Working) standard
| Reference standard |
|---|
| Highly purified material or prepared by independent synthesis |
| Fully characterised like NMR, Mass, IR, CHN etc |
| Received from authentic pharmacopeia sources like UPS, EP, BP, JP, Ph Int. etc |
| Can be used as such or used to qualify the secondary standard for routine use |
| Potency assigned based on the mass balance |
| Secondary (Working) standard |
|---|
| Approved material
having the highest purity |
| Qualified against the reference standard |
| Approved material received from vendor or manufactured in-house |
| Can be used as secondary standard for routine use |
| Potency assigned based on the mass balance or against reference standard |
| Reference standard |
|---|
| Can be used till its expiry |
| Absence of pharmacopeia standard an in-house reference standard can be prepared and used |
| It is highly advisable to apply water correction at the time of use if is hygroscopic material |
| Secondary (Working) standard |
|---|
| Can be used till its expiry |
| Bulk quantity of materials can be qualified and used for routine analysis |
| Periodic requalification is required |