Application of povidone in pharmaceutical industry

With the development of pharmaceutical preparation technology, POvidone has been used more and more widely as pharmaceutical excipients of non-ionic

water-soluble polymer compounds. However, different preparations need to be selected for different types of POvidone, and there are many technical details in

its application that require the user’s special attention. According to the actual situation of first-line production, it is divided into…… from different angles as binder, coprecipitant, co-solvent, etc.

According to the excellent physiological compatibility of POvidone series of pharmaceutical excipients is its inherent and unique product properties, to now, it has become the three main synthetic pharmaceutical excipients together with cellulose derivatives and acrylic compounds.

Povidone series can be a variety of models according to different K values, of which the most widely used varieties are K15, K30 and K90. The Chinese Pharmacopoeia only lists the quality standard of K30, while the British and American pharmacopoeia lists all POvidone K series as a whole standard. Povidone, as a medicinal excipient, has many kinds of preparation uses, and its application details deserve attention.

1. The use of POvidone as binder helps to prepare compressible particles that can flow freely, and ultimately produce tablets with strong solubility and good hardness. Povidone K30 is generally used as a binder, and its dosage in tablets is generally 2% to 5%, and the use 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 soluble in both water and ethanol, the alcohol solution of POvidone can be used for granization of water-sensitive, heat-sensitive and volatile drugs, which not only solves the problem of drug stability, but also reduces the drying temperature and shorens the drying time.

The use of POvidone as a binder for effervescent tablets requires special attention. Since water is not allowed during the preparation of effervescent tablets, POvidone that is soluble in both water and anhydrous ethanol becomes an ideal binder. The vinylpyrrolidone – vinyl acetate copolymer now appearing on the market is the best adhesive for the preparation of effervescent tablets, the amount of use is generally 2% to 5%, and the use concentration is generally 5% to 10%.

2, coprecipitant has many drugs with good efficacy, but due to its small solubility in water, its bioavailability is reduced. The carbonyl group in the POvidone molecule and the active hydrogen atom in the insoluble drug molecule are combined by hydrogen bond, so that the drug molecule becomes an amorphous state into the completely water-soluble POvidone macromolecule, thus inhibiting the formation and growth of the crystals of the insoluble drug molecule, and becoming a supersaturated state, which can greatly improve the solubility of the insoluble drug.

In general, the dissolution rate V of different K values of POvidone and most drug coprecipitates follows the rule of VK15 < VK30 < VK90, while the coprecipitates formed with nitrophenyridine and phenytoin are exceptions. How to choose the right coprecipitator, the production enterprise needs to consider the selection according to the characteristics of their own products.

3, co-solvent or dispersion stabilizer POvidone as a co-solvent or crystal growth inhibitor in the injection has also been more and more widely used, this solubification is mainly the combination of drugs and POvidone produced. It is worth noting that because the diameter of the capillary tube of the human kidney is about 7 nanometers, POvidone entering the human blood can be successfully discharged through the renal tubules only when the spiral body is less than 7 nanometers, that is, the corresponding molecular weight is less than 30,000, and the molecular weight of POvidone used as an injection should not be greater than 30,000. Since POvidone is the product of free group polymerization, there is a problem of molecular weight distribution, in order to ensure that the POvidone used in the injection does not contain products with molecular weight greater than 30,000, it is recommended to use POvidone with an average molecular weight of about 2500, and POvidone K12 and POvidone K17 are generally used as co-solvents in the injection.

4, coating or film forming agent in the coating, the high bonding force of POvidone increases the adhesion of the coating to the drug base; The excellent dispersibility increases the stability of coated suspension and avoids the reuniting and migration of pigment. Excellent film formation prevents fine cracks on the coating surface during drying. K25 and K30 are mainly used as coating materials in POvidone, and now vinylpyrrolidone – vinyl acetate copolymers in the domestic market have also been widely used as coating materials.

5, drug slow release or controlled release In the preparation of insoluble skeleton or corrosion skeleton slow release preparations, POvidone is often used as a pore-causing agent, adjust the amount of POvidone to adjust the drug release rate, and adopt the appropriate preparation process to obtain the optimal drug dissolution mode. Povidone K90 with high molecular weight can be used to prepare hydrophilic gel sustained-release tablets, and the drug release rate can be adjusted by changing the ratio of skeleton material to drug dosage.

In addition, povidone series is also widely used in eye aid, capsule flow aid and so on. With the continuous improvement of the level of domestic pharmaceutical preparations, POvidone will be more and more widely used, and its application prospect will be more optimistic.