Povidone Application Details Popular Science

The excellent physiological compatibility of the povidone series of pharmaceutical excipients is its inherent and unique product performance. Today, it has become the three major synthetic pharmaceutical excipients together with cellulose derivatives and acrylic compounds. The povidone series can be divided into various types according to different K values, among which the widely used varieties are K15, K30 and K90. The Chinese Pharmacopoeia only includes the K30 quality standard, while the British and American Pharmacopoeia includes all the povidone K series as a whole standard. As a pharmaceutical excipient, povidone has many uses in preparations, and its application details deserve attention.

1. Adhesive

The use of povidone facilitates the manufacture of free-flowing compressible granules, which ultimately result in highly soluble, firm tablets. Povidone K30 is generally used as a binder, and its dosage in tablets is generally 2% to 5%, and its concentration is generally 0.5% to 5%. For loose raw materials, povidone K90 with strong bonding ability can be selected, and the general dosage is less than 2%. Since povidone is easily soluble in water and ethanol, it can be granulated with a povidone alcohol solution for water sensitivity, heat sensitivity, and volatility, which not only solves the problem of stability but also reduces dryness. The temperature will shorten the drying time.

2. Cosolvent or Dispersion Stabilizer

Povidone is also increasingly used in injections as a cosolvent or crystal growth inhibitor. This solubilizing effect is mainly the effect of combining with povidone. It is worth noting that since the diameter of the human renal capillary is about 7 nm, povidone entering human blood can only be excreted through the renal tubule when its spirochete is smaller than 7 nm, that is, the corresponding molecular weight is less than 30,000. Therefore, the molecular weight of povidone for injection should not be greater than 30,000. Since povidone is a free-radical polymerization product, there is a problem with molecular weight distribution. In order to ensure that povidone for injection does not contain products with a molecular weight greater than 30,000, it is recommended to use povidone with an average molecular weight of about 2,500, which is generally used as a co-solvent for injection. Most of the povidones used are povidone K12 and povidone K17.

3. Coatings or film formers

In the coating, the high adhesion of povidone increases the adhesion of the coating to the drug base; the excellent dispersibility increases the stability of the coating suspension and avoids the depolymerization and migration of the pigment; excellent film properties Prevent micro-cracks on the surface of the coating during drying. K25 and K30 are mainly used as coatings for povidone. Today, vinylpyrrolidone-vinyl acetate copolymers in the domestic market are also widely used as coating materials.

4. Porogen

Sustained or controlled release When preparing insoluble or erodible matrix sustained-release preparations, povidone is often used as a pore former, and the release is regulated by adjusting the dosage of povidone, and the appropriate dissolution technology can be obtained from the preparation. High molecular weight povidone K90 can be used to prepare hydrophilic gel-type sustained-release tablets, and the release rate can be adjusted by changing the ratio and dosage of matrix materials.

In addition, the povidone series is also widely used in ophthalmic auxiliary, capsule glidant, and so on. With the continuous improvement of the domestic preparation level, the application of povidone will become more and more extensive, and its application prospect will be more optimistic.