Insoluble polyvinylpyrrolidone Crospovidone

Soluble polyvinylpyrrolidone was first used during World War II as a blood-plasma substitute. Although it has excellent properties for this purpose, it has no longer been used for a number of decades. The organism does not metabolize the polymer, with the result that after parenteral administration, small quantities of high-molecular components may remain within the body. This problem does not exist with oral administration. 

soluble polyvinylpyrrolidone (povidone) is one of the most versatile and widely used pharmaceutical auxiliaries (see Section 2.4). 

It is also used in the production of one of the most important topical disinfectants, povidone-iodine. 

Insoluble polyvinylpyrrolidone (crospovidone) is obtained by popcorn polymerization of N-vinylpyrrolidone [2], which yields a mainly physically crosslinked polymer [4-6]. The process is illustrated in Fig. 4 and uses either an alkali hydroxide at temperatures over ioo°C, which yields some bifunctional monomer, or a small percentage of bifunctional monomer in water to initiate crosslinking of the polymer. 

A comparison of the infrared spectra of the main physically crosslinked popcorn polymer obtained as shown in Fig. 4 and that of soluble polyvinylpyrrolidone shows practically no difference, while the infrared spectrum of a chemically crosslinked insoluble polyvinylpyrrolidone polymer prepared in the laboratory is quite different, which proves that the crosslinking in the crospovidone polymer is essentially of a physical nature. 

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In systematic investigations into the dependence of complex formation on structure, no difference was found between soluble polyvinylpyrrolidone (povidone) and insoluble polyvinylpyrrolidone (crospovidone) for complexes with organic compounds [192]. 

Insoluble polyvinylpyrrolidone (crospovidone) is manufactured by a polymerization process that produces a mainly physically crosslinked popcorn polymer [2]. 

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