Learning Objective

• Introduction to powders
• Preparation and analysis of powders

A powder is a homogenous mixture of more or less finely divided particulate material in dry form. Although the use of powders as a SDF has declined yet they are the starting material in the manufacture of many dosage forms. Powders are one of the oldest dosage forms and are used both internally and externally. They impart flexibility (with regard to a wide selection of drugs, combination and dosage ranges), stability (drugs like aspirin and penicillin are more stable in powdered form than in solution), rapid therapeutic effect (rapid attainment of therapeutic blood levels and rapid absorption from finely divided powders due to large specific surface area), and ease of administration to all categories of patients. However, the preparation of powders is not a suitable dosage form for unpleasant tasting, hygroscopic and deliquescent drugs.

Advantages

1. Powders are more physically and chemically stable when compared to liquid dosage form.
2. The drug product in the powder dosage forms is less prone to microbial contamination.
3. It is an ease mode of drug administration when the dose is very large.
4. It is well accepted by pediatric and geriatric patients.
5. The rate of dissolution and absorption is faster in powder dosage form when compared to any other SDF.

Disadvantages

1. Powders are bulky dosage form and causes difficulty in handling and transport.
2. They are not easily transferrable from a container and may spill.
3. The method of preparation and packaging are time consuming.
4. Drug substances that are having an unpleasant taste are not suitable to administer in powder form.
5. The substances that are hygroscopic, deliquescent, volatile and oxygen sensitive are not suitable to be administered in powder form.