Assay and Content Uniformity procedure

[jayroseville58]

For Assay Procedure:

Weigh about 836.0 mg of powdered tablet (equivalent to 100mg of Active) into a 200ml VF. Add 150ml of diluent and shake mechanically for 30 minutes to dissolve. Dilute to volume with diluent and mix. Centrifuge a portion of the prepared solution at 3000 rpm for about ten minutes. Use the upper liquid for injection.

For Content Uniformity Procedure:

Transfer one tablet into a 100-ml volumetric flask. Add 50ml of methanol and sonicate for 15 minutes with intermittent shaking to dissolve. Add 20 ml of buffer pH 6.0 and shake mechanically for 30 minutes. Dilute to volume with buffer pH 6.0 and mix. Centrifuge a portion of the prepared solution for ten minutes at 3000 rpm. Filter the above solution with 0.2micron GHP syringe filter and inject the clear solution.

NOTE: Tablet label claim is 50mg Active/tablet. Diluent Composition was [buffer pH 6.0: Acetonitrile: Methanol (300:600:100)]

Question:

Is the content Uniformity procedure above is correct with respect to the Assay Procedure used?
Is it possible that the assay of individual tablet can deviate it's procedure from the Assay procedure itself?

[Fernando]

Hi jayroseville58

I don't understand why in the CU you don't use about 80 ml of diluent, then sonicate, etc and then fill with diluent to the mark.
In the assay it is OK to centrifugate and then to filter with 0,2 µ.

Fernando

[jayroseville58]

Hi jayroseville58

I don't understand why in the CU you don't use about 80 ml of diluent, then sonicate, etc and then fill with diluent to the mark.
In the assay it is OK to centrifugate and then to filter with 0,2 µ.

Fernando

On the actual experiment, the tablet was at first diluted with the diluent. However, individual tablet cannot be dissolved by diluent that was used from the assay. Modification was made and methanol was directly added for dissolution of the sample. Is this method correct?

[bundy5555]

I didn't get what is you question is. Are you asking if your CU sample prep procedure can extract all the API?

[jayroseville58]

I didn't get what is you question is. Are you asking if your CU sample prep procedure can extract all the API?

What I mean is, let say we have a particular sample tablet (official on the USP monograph). There is an assay procedure as stated with the method I wrote above. My tablet as per USP follows Content Uniformity instead of weight variation method for the Uniformity of Dosage Units test. Normally the assay of the individual tablet should follow whatever Assay method is indicated as per the tablet's official monograph. Can I make deviations on the Content Uniformity assay procedure not following let say the solvent to be used for dilution used on the specified Assay test? Is this allowable?