Spray-congealed microparticles for drug delivery - an overview of factors influencing their production and characteristics.
BACKGROUND
In any manufacturing process, the success of producing an end product with the desired properties and yield depends on a range of factors that include the equipment, process and formulation variables. It is the interest of manufacturers and researchers to understand each manufacturing process better and ascertain the effects of various manufacturing-associated factors on the properties of the end product. Unless the manufacturing process is well understood, it would be difficult to set realistic limits for the process variables and raw material specifications to ensure consistently high-quality and reproducible end products. Over the years, spray congealing has been used to produce particulates by the food and pharmaceutical industries. The latter have used this technology to develop specialized drug delivery systems.


METHODS
In this review, basic principles as well as advantages and disadvantages of the spray congealing process will be covered. Recent developments in spray congealing equipment, process variables and formulation variables such as the matrix material, encapsulated material and additives will also be discussed.


CONCLUSIONS
Innovative equipment designs and formulations for spray congealing have emerged. Judicious choice of atomizers, polymers and additives is the key to achieve the desired properties of the microparticles for drug delivery.
National University of Singapore, Department of Pharmacy, GEA-NUS Pharmaceutical Processing Research Laboratory, Faculty of Science , Block S4, 18 Science Drive 4, 117543 , Singapore.
Ching Mien
CM
Oh
Qiyun
Q
Guo
Paul
P
Wan Sia Heng
Lai Wah
LW
Chan
D000336:Aerosols / Q000737:chemistry*; D000818:Animals; D002626:Chemistry, Pharmaceutical; D016503:Drug Delivery Systems; D006801:Humans; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry*; D009330:Nebulizers and Vaporizers; D013501:Surface-Active Agents / Q000737:chemistry*
D000336:Aerosols; D013501:Surface-Active Agents
atomizers; formulation variables; principles; process variables; spray congealing