Review Article

Imagine the Superiority of Dry Powder Inhalers from Carrier Engineering

Table 8

Dry powder coating technologies for manufacturing versatile powders/particles [82, 83, 90].

Technologies Speed/shear rateFunctionality/principleLimitations

CyclomixRotor speed up to 30 m/s and high shearMild coating technique. Specifically, designed for cohesive powders with liquids or melt binders and with excellent temperature control system.Not applicable for fragile host material. May lead to particle attrition or fracture of host materials.

Fluid energy millMicronization coatingMost commonly used for fine grinding and close particle size control (less than 10 μm).Less mechanical force produced compared to other high force technologies. Continuous attrition of particles generating amorphous form or different polymorphs. Need to monitor various variables to ensure desired particles morphology.

Hybridiser5000–20,000 rpm and high shear with compression forcesTemperature based fusion with ensuing good homogeneity. Producing satisfactory physical and/or chemical bond within very short procession time.
Not suitable for thermolabile and fragile material and may lead to particle attrition or fracture of host materials. May generate amorphous form or change chemical and electronic status of material. Not suitable for continues process.

Mechanofusion200–10,000 rpm and high shearTemperature based fusion between guest and host particles. Generating very strong physical and/or chemical bonding.Not applicable for thermolabile and fragile host material. Not suitable for continuous process.

Magnetically assisted impaction coatingHigh shear force and use of magnetic fieldSoft coating technique suitable for thermolabile material. Minimum impact on particle shape and size.Not suitable for continuous batch process. High risk of contamination. Less mechanical force produced compared to other high force technologies.

Rotating fluidized bed coaterCentrifugal fluidization and shear forcesSoft coating technique suitable for smaller size small host and guest particles. Suitable for continuous batch process operation.Unnecessary aerosolization of fine guest particles. Less mechanical force produced compared to other high force technologies.

Theta-composer (elliptical rotor)500–3000 rpm and shear stress with compaction forceSoft coating and no thermal deterioration with short processing time of 2–10 min. No major change in particle size or shape.Not suitable for continuous batch process. Less mechanical force produced compared to other high force technologies.

Turbo rapid variableImpeller tip speed up to 20 m/sHigh shear blending unit contains a single, bottom driven impeller drive. Suitable for continuous batch process operation and provide homogenous product.Not applicable for thermolabile and fragile host material.