Reference standards

Bujji Kanchi

Purpose

• Identification• Quantification

Akbar wants to shorten the line

Using Reference standard line only, We should compare and judge

How to Measure length ?

• Using a scale.

• Then, Scale is a Reference standard to measure.

Do U want to measure weight of ?

In daily life, we use to buy things by measuring against standard weights

So, For every measurement, There needs a reference standard.

Hence for every quantification, Reference standard is required for accuracy

Identification

• Any material is identified with its reference standard.

• A material is compared against its reference standard for Identity. Eg: IR

Types of Standards• Reference standards are of two types

1. Primary Reference standards. 2. Secondary Reference standard or working reference standard.

Primary Reference standards or primary standards

• Primary standards are the chemical substances which are accepted without reference to other standards.

• No testing is required for primary reference standard, directly it can be used with out further testing in our lab.

Primary Reference standardPharmacopial or In-house

• Primary standard may be obtained from the USP/NF or EP or BP and other official sources or prepared by the manufacturer.

• If there is no official source to obtain material (In-house products).

Primary std should be properly identified.

• Primary standards are characterized for proper identification by exclusive testing like

• IR• NMR• MASS• UV/Vis• CHN analysis

Evaluation of potency.

• %Potency = 100-All impurities(including water and residual solvents)• If a standard requires drying, the required amount must be

transferred to a clean weighing bottle for drying. • The weighing bottle must be protected from light during use. Dried

standards must not be returned to the original bottle in order to avoid any possible contamination of the stock. After drying, place the standard into the desiccator to equilibrate before assaying.

Working reference standard

• Pharmacopeial primary standards are costly and single use only. We can not buy every time.

• To over come this, Instead of Primary standards, working

standard can be used.

Packing and labeling

• Pharmacopial PRS should be used directly for any testing, No further packing is required.

• In-house PRS should be packed in 12 amber color glass bottle for one year,

• Each bottle should be used for only one month.

Packing and labelling

• This is a best practice to avoid attacking Moisture from atmosphere for multiple use.

• Three buffer vials should be kept for sake of spillage or customer requirement etc..

• Pack the working standard like In-house PRSPacking for one year

• 12 containers+ 3 buffer containers

COA for PRS

• Pharmacopial standard does not provide COA• Only certificate is provided.• We should check that # The current lot of primary standard should be

in place.• In-house PRS should have COA.

USP Certificate

Working standard

• A working standard is a standard that is qualified against and used instead of the reference standard.

• There are generally used for regular analysis of drug substances.

• Working standard becomes In-house.• COA is prepared.

Retest or Expiration dating:

• The retest or expirations dating for primary reference standards can be obtained from the official source. In case of in-house reference standards retest date can be assigned by the stability and sensitivity of drug substance.

• In case of secondary standards, usually one year is the retest period. This parameter always depends on the stability of the drug substance.

Storage of Standards

• Working standards are stored in the same manner as indicated by the official source or stability of the standard and are stored in amber glass containers, protected from light, heat and moisture.

Storage of Standards

• Working standards should be kept at ambient conditions in an amber dissector cabinet, unless otherwise specified by the individual monograph and if the standard that require storage in a "cold" or "dry" place are to be stored in a refrigerator at 2-8°C.

Working standard

• Working standard purity is verified periodically, If it is been used for more than one year.

• Even for Key starting materials, In-house PRS must be evaluated and used.

• Select the batch for the working standard qualification, which is highly pure.

Precautions

• Working standard can not be used for qualifying another working standard

• Expired vials should not be used.• Current lot should be used for Pharmacopial

standards• Current lot of In-house standards should be in

place for every month

Correct labeling of vials

Inward and Consumption of Pharmacopeial standard

• Inward should be maintained for each purchase of standard .

• Usage log must be recorded.

Usage # Pharmacopial standards

Pharmacopial standards for Multiple useUsed for Identification Eg: MR standards.-----------------------------------------------

Pharmacopial standards for single useUsed for quantification

Thank you

• Questions ?