Solid Dosage Forms 1 Flashcards
Unit Operations in Pharmacy Manufacturing
- Size Reduction
- Granulation
- Drying
- Compression
- Encapsulation
- Mixing and Blending
- Filtration and Clarification
- Sterilization
Process of reducing larger size solid unit masses to
smaller size unit masses by mechanical means
Reasons to reduce particle size:
Size reduction
Principle means of size reduction
- Cutting or shearing
- Compressing
- Impaction
- Attrition
- Combined impaction and attrition
Factors in choosing a mill
- Properties of feedstock
- Specification of product
Process by which poser particles are made to
adhere to form larger particles
Granulation
reasons for granulation
- Prevent segregation of constituents in
powder mix - Improve the flow properties of the
powder mix because particles are larger
and more isodiametric - Improve compression characteristics of
mix
Methods of granulation
wet granulation
dry granulation
hot melt granulation
“Wet massing”
Massing of the powder mix using a solvent (alone
or within a granulating agent)
Wet granulation
Solvents used in wet granulation
- water
- organic solvents
It is nonflammable, nontoxic, undergoes hydrolysis, and has long drying time
water
it is an alternative to dry granulation, used for water-sensitive drugs, and rapid drying
organic solvents
examples of wet granulation equipment
- Shear granulator
- Fluid bed granulator
- Spray dryer
- Spheronizer/pelletizer
Particles are aggregated using high pressure
For drugs which do not compress well after wet
granulation and are sensitive to moisture
Dry granulation
2 processes for dry granulation
slugging
roller compaction
Process of putting together in one mass with more or less thorough diffusion blending
Mixing
Classification of Mixing Equipment
- batch type
- continuous type
Process of removing water (or other liquid) from a
solid or semisolid mass by evaporative process
Drying
factors in choosing a drying equipment
nature of product
cost
examples of drying equipment
- Tray dryer
- Vacuum dryer
- Infrared dryer
- Radiofrequency dryer
- Fluid bed dryer
Solid Dosage Form Excipients
- Diluents
- Binders
- Lubricants
- Glidants and Antiadherents
- Disintegrants
- Superdisintegrants
- Added Functionality Ingredients
- Colorants
Should be chemically inert, nonhygroscopic, and hydrophilic. An inert substance is frequently added to increase the bulk of a tablet for processing and handling.
- Lactose
- Starch
- Sucrose
- Mannitol
- Sorbitol
- Microcrystalline cellulose
- Hydrolyzed starch
Promote cohesiveness within powders, thereby ensuring that the tablet remains intact after compression as well as improving the flow by forming granules impart adequate cohesion without retarding disintegration or dissolution
Binder
Binder examples
- Water
- Alcohol
- Starch Paste
- Acacia Mucilage
- Gelatin Solution
- Tragacanth Mucilage
- Sucrose Solution
- Methylcellulose Solution
- Sodium CMC Solution
- PVP Solution
- Sorbitol
reduce friction between the tablet and the die wall during compression and ejection
Lubricant
Fine powders and may be required for tablet compression at high production speeds to improve the flow properties of the material into the die or during initial compression stages
They are added in the dry state immediately prior to compression and, by virtue of their low adhesive potential, reduce the friction between particles
Glidants and antiadherents
added to a formulation to overcome the cohesive strength imparted during compression, thus facilitating break up of the formulation in the body and increasing the surface area for dissolution.
They can be either intragranular, extragranular, or
both
Disintegrant
Mechanism of Action of Disintegrant:
- Swelling
- Porosity and Capillary Action (Wicking)
- Deformation
example of disintegrants
- Starch
- Starch derivatives
- Gums
- Cellulose derivatives
- MCC (Avicel)
- Alginates
- Clays
- Effervescent mixtures
- Enzymes
so called because of the relatively low levels
required (2 – 4% w/ w)
Superdisintegrant
Three superdisintegrants
- Sodium starch glycollate (primojel, explotab)
- Crospovidone
- Croscarmellose sodium
- modified starch
- made by cross-linking potato starch
- can swell up to 12 - fold in less than 30 s
Sodium starch glycollate
- cross-linked povidone
- completely insoluble in water
- rapidly disperses and swells in water, but does
not gel even after prolonged exposure - It rapidly exhibits high capillary activity and
pronounced hydration capacity
Crospovidone
- modified cellulose
- a cross - linked polymer of carboxymethyl cellulose sodium
- insoluble in water
- rapidly swells to 4 – 8 times its original volume on contact with water
croscarmellose sodium
