Mechanical methods for dry particle coating processes and their applications in drug delivery and development

Modification of the surface properties of particles, which is usually achieved by coating, is desirable to maintain and enhance the utility of these particles. Saving of time, energy, number of additives, process steps and consequently, the cost of the coating process leads to development of dry coating processes using mechanical methods which exclude any liquid solvent or binder solution and are environmentally safe, and cost-effective. Mechanofusion, hybridization, magnetic assisted impaction coating, theta-composer, rotating fluidized bed coating, pressure swing granulation and high shear mixing have been extensively patented and reported in the scientific literature. These mechanical methods have found multidisciplinary applications in drug development and drug delivery. Various devices available for the dry coating process, their principle, method of working, benefits and limitations along with various applications relevant to the pharmaceutical field are discussed in the current article.