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

The limits should be like this
ReplyDelete±10%, ±7.5% and ±5%, because a limit, in general should have lower to upper values.
You are absolutely right..... A limit in general should have lower & upper values.Blog have been updated accordingly. Thanks for your valuable comments...
ReplyDeleteWelcome!!
DeleteWhat is the difference between weight variation, uniformity of weight, uniformity of dosage unit and range of mean weight?
ReplyDeleteAlso, is there any circumstances that allow different upper and lower limit?
Thank you.
“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.
ReplyDeleteRefer USP <905> uniformity of dosage units
the limits mentioned under USP is for weight variation for dietary supplements. does this apply to all other tablets? as mentioned by u in USP "Uniformity of dosage units can be demonstrated by either of two methods, 1). Content Uniformity ( by assay test) or 2). Weight Variation.". But under weight variation they are calculating content. CLARIFY.
Deletewhat are the usefulness of uniformity of weight test in pharmacy
ReplyDeleteMay I know which edition of BP and USP for the table above?
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteIs 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?
ReplyDeleteHow much tablets fall range of limit and that's fall limit ?
ReplyDeletewhat is the importance of uniformity of weight test in pharmacy
ReplyDeleteWhy are coated tablets exempted from weight variation test?
ReplyDeleteThe applicable tolerance limit should be applied on the calculated average value or on the nominal weight value of the tablet.
ReplyDeleteIn Many companies they are calculating the limit based on the tablet's nominal weight.
ReplyDeleteany bdy tell the relationship b/w weight variation nd therapeutic activity of a dosage form
ReplyDeleteiif you use 10 units will the limits still apply?
ReplyDelete