Wednesday, 9 May 2012

Tablet weight variation and uniformity of weight of single dose preparations - Pharmacopeal requirements IP/BP/USP



TABLET WEIGHT VARIATION AND UNIFORMITY OF WEIGHT




Tablet weight is mainly affected by factors such as tooling of the compression machine,head pressure,machine speed and flow properties of the powder.Inconsistent powder or granulate density and particle size distribution are common sources of weight variation during compression.


Variation between tablet with respect to dose and weight must be reduced to a minimum.Uniformity of weight is an in process test parameter which ensures consistency of dosage units during compression.


Test Procedure
Weigh individually 20 units selected at random and calculate the average weight.Not more than two of the individual weights deviates from the average weight by more than the percentage given in the pharmacopea and none deviates by more than twice that percentage.IP/BP & USP limits for tablet weight variation is given below.
                                        

IP/BP
  Limit
USP
80 mg or less
± 10%
130mg or less
More than 80mg or Less than 250mg
± 7.5%
130mg to 324mg
250mg or more
± 5%
More than 324mg





8 comments:

  1. The limits should be like this
    ±10%, ±7.5% and ±5%, because a limit, in general should have lower to upper values.

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  2. You are absolutely right..... A limit in general should have lower & upper values.Blog have been updated accordingly. Thanks for your valuable comments...

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  3. What is the difference between weight variation, uniformity of weight, uniformity of dosage unit and range of mean weight?

    Also, is there any circumstances that allow different upper and lower limit?

    Thank you.

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  4. “Uniformity of dosage unit” is defined as the degree of uniformity in the amount of the drug substance among dosage units. Uniformity of dosage units can be demonstrated by either of two methods, 1). Content Uniformity ( by assay test) or 2). Weight Variation.

    Refer USP <905> uniformity of dosage units

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  5. what are the usefulness of uniformity of weight test in pharmacy

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  6. May I know which edition of BP and USP for the table above?

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  7. This comment has been removed by the author.

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  8. Is there any method or any systems should we get just zero percent weight variation tablet? & if we can get this then what are the advantages of that?

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