Suppositories average content

Table 11.13 Sources of Error affecting the Average Content of suppositories...

Settling during pouring Is of little importance for the average content, but of significant importance for the content uniformity of separate suppositories, see 11.5.5... 

Insufficient mixing will usually result in insufficient content uniformity, but with complex processes such as the preparation of suppositories, it may even result in a deviation in the average content, see Sect. 11.8.3. 

In the Netherlands it is commOTi to use a requirement of 3 % as a limit to the deviation of the average mass towards the calculated mass for capsules and suppositories. Eor single dose powders this requirement is 5 %. In practice these limits appear to be acceptable and are achievable. When these limits are exceeded, then there are, in principle, two possibilities reject the preparatirai or check the average content. When the content comphes, the preparatirai need not be rejected on the basis of the average mass discrepancy. However the cause of the deviation should be investigated and traced and corrective measures should be taken for future batches. 

The requirements and assay of average content has been discussed in Sect. 32.4. When a medicine consists of single dosage units, the contents of those separate units (tablets, capsules, suppositories)have to meet content requirements. The separate assay values are used for estimation of the average content but also to estimate the variation between the units (uniformity of content). The separate mass values also have to meet requirements. The mass variation may give some indication of the content variation. 

The Ph. Eur. does not make a recommendation on the minimum number of units to be tested, or the minimum size of the sample. The British Pharmacopoeia (BP) [2] is clearer. The BP describes that the average craitent of capsules or tablets has to be determined on 20 units. From this a mixed sample is taken, on which the content is assessed. The BP does not describe a general amount for suppositories. In most of the separate monographs for suppositories however a mixed sample of 10 units is taken. 

Eor suppositories not more than 2 of the individual masses deviate more than 5 % of the average mass and no suppository may deviate more than 10 % of the average mass. Eor capsules with a content weight less than 300 mg these percentages are respectively 10 and 20 %, for capsules with a content weight equal to or more than 300 mg respectively 7.5 % and 15 %. For other pharmaceutical forms reference is made to the monograph. 

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