Aqueous suspension preparations

Abstract

Addition of polyvinylpyrrolidone and a water-soluble anionic macromolecular compound to an aqueous suspension of a hardly soluble drug allows to provide an aqueous suspension in which aggregation of drug particles, formation of macro crystals from suspended particles and formation of secondary particles from deposited particles are prevented, and adhesion and adsorption to containers made of plastics, e.g., polypropylene or polyethylene, are avoided. As it has a good redispersibility, the aqueous suspension is useful as eye drops, nasal drops, ear drops, injections, oral preparations, liniments and lotions.

Description

[0001] The present invention relates to an aqueous suspension with good redispersibility comprising polyvinylpyrrolidone and a water-soluble anionic macromolecular compound which are added to prevent a hardly soluble drug from adhering to a container and forming aggregates.[0002] Aqueous suspensions often have problems such as difficulty in redispersion due to aggregation of drug particles, formation of macro crystals from suspended particles or formation of secondary particles from deposited particles, any of which could take place during long-term storage or when they are exposed to temporary heating or fluctuation of temperature / humidity. In addition, some types of suspended particles adhere to or get adsorbed by the walls of a plastic container and could thus cause a problem of unstable concentration of the drug contained in the aqueous suspensions.[0003] To address these problems, measures have been taken in order to prevent formation of secondary particles by blocking sediment...

AI Technical Summary

Benefits of technology

[0007] The objective of the present invention is to provide an aqueous suspension with good redispersibility.

[0008] As a result of studies performed to solve the above-mentioned problems, the inventors of the present invention surprisingly found that addition of polyvinylpyrrolidone and a water-soluble anionic macromolecular compound improves the redispersibility of hardly soluble drugs in an aqueous suspension, and completed the present invention based on the finding.

[0036] (27) a method for improving the redispersibility of an aqueous suspension of a hardly soluble drug comprising addition of polyvinylpyrrolidone and a water-soluble anionic macromolecular compound to the aqueous suspension,

[0051] The excellent redispersibility of the aqueous suspension of the present invention allows itself to be used as a medicament (e.g., drugs for prophylaxis or treatment of various diseases) for a human and as a veterinary drug for other mammalian animals (e.g., rats, mice, guinea pigs, monkeys, dogs, bovines, pigs, etc.).

Problems solved by technology

Aqueous suspensions often have problems such as difficulty in redispersion due to aggregation of drug particles, formation of macro crystals from suspended particles or formation of secondary particles from deposited particles, any of which could take place during long-term storage or when they are exposed to temporary heating or fluctuation of temperature / humidity.

In addition, some types of suspended particles adhere to or get adsorbed by the walls of a plastic container and could thus cause a problem of unstable concentration of the drug contained in the aqueous suspensions.

However, while it is not possible to completely prevent sedimentation of suspended particles by reducing the size of the particles in the suspension and increasing the viscosity of the dispersion medium, this measure could cause a problem by making it more difficult to redisperse particles which are once deposited from the suspension.

On the other hand, increasing of the size of particles in the suspension would cause problems such as foreign body sensation upon application or clogging of a container nozzle or a syringe needle.

This method, however, cannot be used when high levels of viscosity is desired for improvement of the retention of a drug, because the redispersibility in this method is acquired by its low viscosity of 100 cP.

As it employs low concentrations of an aqueous macromolecular compound, this method cannot be used, either, when addition of higher concentrations of the macromolecular compound is needed for other reasons, e.g., for improvement of the retention of a drug.