Mixing of powders
- S-1-Pharmaceutics I
- Feb 27
- 1 min read
Updated: Mar 2
Buy Now the Hard Copy of notes for seamless and ad-free learning, Click Below!
Mixing powders is a critical process in preparing pharmaceutical products like tablets, capsules, and bulk powders.
The goal is to create a homogenous blend of active ingredients and excipients for consistent dosing.
Powder mixing can be done through manual or mechanical methods.
1) Manual Mixing of powders
Manual mixing techniques involve the use of simple tools like spatulas, mortars, and pestles for blending the powders.
a) Spatula Mixing
Powders are blended on a flat surface using a spatula by cutting, folding, and pressing until uniformly mixed.
b) Trituration
A mortar and pestle are used to grind and mix powders in a circular motion for a uniform blend.
c) Geometric Dilution
Used when a potent ingredient is mixed with a larger amount of diluent.
Small portions of each are mixed, doubling the quantity with more diluent until the desired blend is achieved.
2) Mechanical Mixing
Mechanical mixing techniques involve the use of specialized equipment to blend the powders, providing more efficient and consistent mixing than manual methods.
a) Tumbling Mixers
Powders are placed in a container that rotates or tumbles.
Examples: V-blenders, double cone blenders.
b) Planetary Mixers
A rotating impeller mixes powders while revolving around the container's axis, ensuring thorough blending.
c) Ribbon Blenders
Consist of a U-shaped trough with a helical ribbon that moves and mixes powders, ideal for large volumes.
d) High Shear Mixers
Use high-speed impellers to create intense shear forces, breaking up and mixing powders, commonly used for suspensions and granulations.
Buy Now the Hard Copy of notes for seamless and ad-free learning, Click Below!
