Pharmaceutical Powders and Granules

Questions and Answers

What is the primary purpose of particle size analysis in pharmaceutical formulations?

To achieve a desired color in the final product

To obtain quantitative data on the size, distribution, and shapes of drug components (correct)

To measure the viscosity of liquid dosage forms

To determine the shelf life of the pharmaceutical product

Which characteristic of powders is NOT influenced by particle size?

Grittiness of solid particles in ointments

Temperature stability of the product (correct)

Rate of drug dissolution

Uniform distribution in mixtures

Which term is NOT used to describe particle size as per USP standards?

Sandy (correct)

Very coarse

Moderately coarse

Fine

What can drug micronization improve in pharmaceutical formulations?

Rate of drug dissolution Signup and view all the answers

How can powders be utilized in the preparation of medicated ointments and creams?

By incorporating them into semisolid bases Signup and view all the answers

What is a characteristic of granules compared to powders?

Granules are more stable to atmospheric humidity Signup and view all the answers

What is the purpose of the wet method in granule preparation?

To moisten the powder and create granules of desired size Signup and view all the answers

Which of the following is true about the dry method of granule preparation?

It is suitable for moisture-sensitive drugs Signup and view all the answers

Which equipment is used in the dry method to create granules?

Granulating machine and roll compactor Signup and view all the answers

Which step is involved in fluid bed processing for granule formation?

Suspending particles while spraying a liquid excipient Signup and view all the answers

Which method measures the terminal settling velocity of particles through a liquid medium?

Sedimentation Rate Signup and view all the answers

What is the primary purpose of trituration in drug comminution?

To grind drug particles in a mortar Signup and view all the answers

How does cascade impaction separate particles?

By successively increasing the velocity of the airstream Signup and view all the answers

What is a significant advantage of using powdered medication compared to tablets or capsules?

They provide easier administration for patients who have difficulty swallowing. Signup and view all the answers

What is a common disadvantage of using powdered medications?

They may have an undesirable taste. Signup and view all the answers

Which method of blending involves the movement of a spatula?

Spatulation Signup and view all the answers

Which method is suitable for external application of powders?

Applied from a powder aerosol. Signup and view all the answers

What is a common outcome of segregation in powder blending?

Uneven distribution of different components Signup and view all the answers

What is NOT a guideline to minimize or prevent segregation during the handling of powders?

Use of low-quality materials. Signup and view all the answers

What does Stoke’s Law relate to in particle analysis?

Calculation of settling velocity in a liquid Signup and view all the answers

What is the effect of reducing particle size in a powder blend?

Increases the number of particles Signup and view all the answers

Which of the following types of powders is used for potent substances and is ready to take?

Divided powders. Signup and view all the answers

What is the primary application of micronized powders?

Administered by inhalation for respiratory conditions. Signup and view all the answers

Which of the following best describes levigation?

A process to prepare ointments and reduce powder grittiness Signup and view all the answers

Which type of powder requires careful weighing of each portion before preparation?

Divided powders. Signup and view all the answers

Which particle size is typically required for effective delivery of micronized medication?

1 to 6 mcm. Signup and view all the answers

What is the primary purpose of slugging in the context of tablet production?

To form large tablets under high pressure Signup and view all the answers

Which of the following is true about effervescent granulated salts?

They can mask the unpleasant taste of drugs through effervescence Signup and view all the answers

What is the consequence of using tartaric acid alone in effervescent granulated salts?

It may cause the granules to lose firmness and crumble Signup and view all the answers

In the context of the dry or fusion method for preparing granules, what role does water play?

It acts as a binding agent within the citric acid molecules Signup and view all the answers

Which granulation process uses water added to alcohol as a moistening agent?

Wet method Signup and view all the answers

Study Notes

Powders

Powders are dry substances made of finely divided particles, used for medicated internal or external applications.
Composed of dry mixtures of drugs and/or chemicals, powders are often included in other dosage forms.
They can blend with fillers for solid dosage forms like tablets and capsules or be dissolved in liquids for various formulations.
Extensive use of medicated powders in making ointments and creams.

Particle Size and Analysis

USP classifies particle size using descriptive terms: very coarse, coarse, moderately coarse, fine, and very fine.
Sieves used for particle size analysis are typically made from brass or bronze.
Analyzing particle size is crucial for determining drug dissolution rates, bioavailability, and uniform distribution in formulations.
Micronized drugs dissolve faster, increase suspension stability, and enhance inhalation delivery to the lungs.

Methods for Determining Particle Size

Sieving: Involves passing powders through a series of sieves.
Microscopy: Uses a calibrated grid to determine size.
Sedimentation Rate: Applies Stokes' Law to measure settling velocity in a liquid.
Light Energy Diffraction: Measures light reduction as particles pass through a sensing zone.
Laser Holography: Uses pulsed lasers to analyze aerosolized dimensions.
Cascade Impaction: Sorts particles into size ranges by increasing air velocity.

Comminution of Drugs

Small Scale:
- Trituration: Grinding in a mortar to decrease particle size.
- Levigation: Reducing particle size to remove grittiness in ointments.
Large Scale:
- Mills and Pulverizers such as FitzMill reduce particle size through rapid blade movement.

Blending Powders

Spatulation: Blending powders using a spatula.
Trituration: Mixing and comminuting powders simultaneously.
Geometric Dilution: Uniformly mixing potent substances with larger volumes of diluents.
Sifting: Produces a light, fluffy result by passing powders through sifters.
Tumbling: Mixing powders in a rotating chamber.
Segregation: Unwanted separation of components, often resulting from sifting or air fluidization.
To minimize segregation: Control dust, transfer steps, and use appropriate hopper designs.

Administration of Powders

Internal Use: Taken orally after reconstitution; can be inhaled for effects.
External Use: Applied to skin using sifters or powder aerosols, marked as “EXTERNAL USE ONLY.”
Advantages include ease of swallowing for patients and faster absorption rates.
Disadvantages consist of unpleasant taste and instability in liquid form, typically necessitating dry powders.

Aerosol Powders

Administered via inhalation through dry-powder inhalers that deliver micro-sized medication particles.
Useful for treating asthma and bronchial disorders; effective particle size ranges from 1 to 6 micrometers.

Types of Powders

Bulk Powders: Non-potent substances like antacids, stored at room temperature.
Divided Powders: Potent substances ready for immediate use, packaged in small paper doses.

Granules

Granules are agglomerates of powdered materials, used in pharmaceuticals due to stability and flow characteristics.
They are less prone to caking and can be produced in spherical shapes.
Prepared using wet or dry methods, making them suitable for tablet formulations.

Wet Method for Granulation

Basic Wet Method: Moisten powder and pass through a mesh to create granules.
Fluid Bed Processing: Combines pre-blending and drying through a liquid excipient spray.

Dry Method for Granulation

Involves compacting powder and breaking into-sized granules using a roller compactor or slugging.
Ideal for heat-sensitive drugs and may lead to production of fines, which can be reprocessed.

Examples of Granules

Biaxin (clarithromycin), Omnicef (cefdinir), Augmentin ES-600 (amoxicillin/clavulanate), Lactinex granules.

Effervescent Granulated Salts

Coarse powders containing sodium bicarbonate and citric/tartaric acid, releasing CO2 upon contact with water.
This effervescence masks undesirable tastes and is prepared using dry or wet methods.

Preparation Methods for Effervescent Granulated Salts

Dry/Fusion Method: Water of crystallization in citric acid binds the mixture; dried at low temperatures.
Wet Method: Uses added water with alcohol to form pliable granulation mass.

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Description

This quiz explores the characteristics and uses of pharmaceutical powders and granules. It covers their physical form, preparation methods, and applications in various dosage forms. Test your knowledge on these essential components of pharmaceutical science.