Determination of povidone in preparations

The various means of detecting povidone in preparations have been described in detail in the literature [17,18]. Not all the detection reactions listed in Table 52 (see also Section 2.3.1.1) are suitable for every pharmaceutical preparation. The best method can only be determined by trial with the preparation involved. 

The separation scheme shown in Fig. 35 can be used for the detection of povidone in solid dosage forms, e.g. tablets, granules, capsules and coated tablets. 

The detection and differentiation of povidone and copovidone obtained in Fraction A I in Fig. 35 is best carried out by thin layer chromatography on silica gel or paper. A suitable eluent is a mixture of 6 parts n-propanol and 4 parts 2N ammonia solution by volume, which gives the Rf values shown in Table 53. The chromatogram is then sprayed with Lugol s solution. 

Electrophoresis can also be used to detect povidone in the presence of copovidone [17]. 

Povidone can be detected in tissue with the aid of chlorazol or Congo Red [143, 144]. 

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