Caps and Tabs

What is an excipient

Inactive ingredient

Physical Dosage Forms

Solid, semi-solid, liquid, gas

‘pessary’

a solid dosage form intended for vaginal administration

‘suppository’

dosage form intended for application within the rectum

Particle properties

physical dimensions/size, shape, surface area, and physical state

How to define spherical particles

diameter

How to define non-spherical particles

dimensions, diameter d of a sphere that occupies the same volume as irregularly shaped particle

Monodispersed particles

all particles are the exact same size→ small polydispersity index (<0.1) ex: coronavirus

Polydispersed particles

particles are different sizes→ large polydispersity index

Tyler mesh size

the number of openings per inch of mesh, the larger the mesh number, the smaller the opening

Surface are of a spherical particle

pi*d², when diameter decreases 2 times, the surface area of each particle decreases 4 times. The combined surface area for the same weight of powder increases 2 fold

True density

density without consideration of voids. ex: gold bar, density= m/v

Bulk density

have to consider interparticle and intraparticle volumes that add to the volume. ex: flour has a higher bulk density that grains or bread

Porosity

the fraction of void volume (air) in a powder material, e= 1- Pbulk/Ptrue, ex: bread has higher porosity than flour or grains

What happens when you reduce particle size

you increase the total surface area

Wettability

Ability to absorb water

What does a high or low angle of repose mean?

Higher→ wants to stay as a droplet, low wetability

Lower→ wants to spread, high wetability

What does high surface tension mean?

High surface tension→ large contact angle of repose → low wettability

What does a low surface tension mean?

Low surface tension→ small contact angle→ high wettability

What do wetting agents do? what are some common ones?

Decrease surface tension, decrease contact angle, and increase wettability. Glycerol, ethanol, surfactants

What is flowability?

Cohesive properties of power. A low AOR= more flowability, A high AOR= less flowability

How do you improve the flowability of a powder?

Increase the particle size because there’s a larger combined particle surface area. Ex: powdered sugar has a larger AD than granulated sugar

Why is blending important?

Ensures the uniformity, consistency, and efficacy of the final product. Poor blending can lead to dose variability and reduced drug potency

What is trituration?

Continuous rubbing/grinding with a mortar and pestle, useful for hard powders, tablets

What is pulverization by intervention?

1. Dissolve in “intervening” solvent (alocohol, acetone)

2. Mix in mortar or spread on an ointment slab

3. The solvent evaporates

Used for hard, crystalline powders that do not easily triturate and gummy substances

What is levigation?

Uses a small amount of solvent in which the particles are insoluble, then triturate, useful for ointments and suspensions

When do you use direct blending?

When the fraction x of powder A is >10%

When do you use geometrical dilution?

When fraction x of A is <10%

Capsules

Solid dosage forms in which a drug substance is enclosed in a hard/soft soluble container/shell

Advantages of Capsules

easily filled, tastless, easily administered, dose can be individualized, preferred in early-stage clinical trials, 44% of consumers prefer capsules over tabs

Diluent

(inert substance), added to increase the bulk weight of a powder in a capsule