Page 4 - Pharmaceutics III_ 02-06-01304_Fall 2025_ Pharm D_Electronic book

Lecture 1 : Powders and Granules

This section provides an overview of pharmaceutical powders and granules, covering their
definitions, applications, physicochemical properties, and processing techniques.

Definitions and Applications of Powders

A powder can be understood in two ways:

1. Physical Form: A dry substance composed of finely divided particles, which can exist
as either amorphous or crystalline structures and are commonly found in active and
inactive pharmaceutical ingredients .

2. Pharmaceutical Preparation: A dosage form consisting of a solid or a mixture of solids
reduced to a finely divided state, intended for internal (oral) or external (topical) use .

Advantages of Using Powders

Powders are a versatile and advantageous dosage form due to:

• Flexible Dosage Provision: Easy alteration of medication quantities tailored to specific
patient needs .

• Rapid Absorption: They disperse quickly, leading to a faster onset of therapeutic action
compared to solid forms, making them preferable for patients needing quick pain relief .

• Suitability for Various Populations: Powders can be easily mixed with food, making
them ideal for infants and young children who may have difficulty swallowing pills .

• Versatile Formulation Options: Powders can be incorporated into various other
formulations, including solid (tablets, capsules), semisolid (ointments, creams), and
liquid dosage forms (solutions, injections) .

• Clinical Study Utility: They facilitate drug testing due to straightforward dose
measurement and administration .

Physicochemical Considerations in Powder Handling

Understanding the physicochemical properties of powders is crucial as they dictate the
behavior of the powder during processing and affect the final product's quality . Key
considerations include:

• Particle Size and Size Distribution: Uniform particles generally blend easier .
Differences in particle size can lead to segregation, where fine particles sift through
coarser ones, resulting in uneven distribution .

• Particle Shape: Spherical particles are typically easier to transport and flow better,
while irregular shapes may present mixing difficulties .

• Density Variations: Particles with high and low densities may not blend uniformly,
affecting content uniformity .

3