subject: By Spray Drying To Improve The Bioavailability Of Drugs [print this page] Recently, administration of drugs for many quantitative terms, the good efficacy but poor solubility of drug controlled release of drugs and made to improve bioavailability of drugs has become extremely important. This paper introduces the use of spray drying technique to produce controlled release and / or high bioavailability of drug products, the main products include nano-particles, micro-encapsulated, solid amorphous dispersion and dry emulsion.
As particles with very large surface area product and high heat exchange coefficient, the spray drying is a very fast drying. Large granules of the surface area can also make drying medium to low temperature environment. Quick drying and moderate temperatures make heat-sensitive materials can be used for spray drying. With the rapid drying and rapid stability of materials made very suitable for embedded and spray drying to produce dry emulsion or amorphous materials. Project also includes the possibility of particle powder performance characteristics, such as aerodynamic particle size, particle geometry, particle size distribution and powder flow characteristics.
Nanoparticles suspended in the spray drying, including drying the appropriate liquid (water) in the nano-particles. After spray drying, the original particles can be protected and at the same time get new ideal powder properties. The powder has good flow properties and reduce the dust generated a trend or a good powder flow properties and a smaller aerodynamic particle size.
By using micro-encapsulation and spray drying process to achieve condensation. Microencapsulation for the spray-dried material is a drug to exist in the form of suspended or dissolved in the liquid in the package material. Suitable solvent can be water, alcohol, acetone. Another alternative way is to spray condensation, this time packing material solution was replaced by the melting of liquid packaging materials. Condensation by spray drying or spray particle size can be very easily changed to fit the controlled release form of debugging and performance by other ideal powder.
Dry emulsion is a variation of micro-encapsulation technology. In the dry emulsion requires embedding the micro-droplets, the oil solution, oil-soluble drugs. Needed to produce dried by spray drying emulsions containing the material is a solid carrier has been dissolved emulsion. After spray drying the dry emulsion can be re-combined to maintain the original droplet size to improve the bioavailability of drugs, while of the other characteristics of an ideal powder.
Solid amorphous dispersions / solutions can be achieved through the use of spray drying. For the production of solid amorphous dispersions of the materials by the stability of drugs and materials with the appropriate solvent,. Suitable solvents include alcohol, acetone, dichloromethane and so on. Spray drying of solid amorphous dispersions of drugs can improve bioavailability and enhance the stability of the drug, while powder features by other ideals, such as powder flow properties and direct compression performance.
Drying When the drugs showed thermoplastic, and when the solvent has a high affinity will result in products difficult to be dried. For drugs with high affinity for the solvent, the product for a defined level of residual solvent content would require higher or lower drying temperature of the exhaust vapor content in the solvent, especially for those who have both thermoplastic products is a considerable challenge. For the performance of thermoplastic and has a lower transition temperature of the drugs, the drying of the effective temperature range is quite limited. Two contradictory factors determine a limited temperature range: Product temperature must be low enough to ensure product stability and bonding does not occur; the same time, drying temperature must be high enough so that the material droplet / particle drying tower wall before collision effective drying time of materials. Worse still, the performance of the material in the solvent as a kind of plasticizer, reducing the temperature of the product allows. Dry conditions will the wrong tower wall as a result of active material was very low rates, low and high drying temperature can lead to this result.
For spray drying, the distinction dryer inlet temperature, product temperature, drying temperature and the dryer outlet temperature is very important. In a well-designed with the flow type spray dryer, the drying temperature and the dryer outlet temperature is the same.
By Spray Drying To Improve The Bioavailability Of Drugs
