Solid Dosage Forms Flashcards
What are the advantages of solid dosage forms?
chemically, physically and microbiologically stable
- compared to liquid dosage forms
enables accurate dosing of the drug during administration
convenient to handle and can be prepared in versatile ways
cheap to prepare/transport/handle
What are the disadvantages of solid dosage forms?
poor bioavailability
- factors affecting F are poor solubility/poor absorption
might cause local irritation
- at the point of entry
What are the advantages and disadvantages of liquid dosage forms?
good bioavailability
inaccurate dosing
susceptible to microbiological growth
- require preservatives (due to presence of water)
What is a diluent?
bulks up the dosage form
- increases weight and improves content uniformity
= lactose, sucrose, mannitol, sorbitol, calcium phosphate
What is a disintegrant?
breaks up the dosage form upon consumption
- maximises SA for dissolution
= starch, cellulose, polyvinyl pyrrolidine (PVP), sodium starch glycolate
What is a solution binder?
holds the tablet/ingredients of the formulation together
- acts as an adhesive
= gelatin, PVP, HPMC, sucrose, starch
What is a dry binder?
holds the tablet/ingredients of the formulation together
- acts as an adhesive
= cellulose, PVP, methylcellulose
What is a glidant?
improves flow ability of the formulation together
- reduced interparticulate friction and cohesion
= silica, magnesium stearate, talc
What is a lubricant?
reduces friction between the material and machinery
- allows smooth ejection
= magnesium stearate, stearic acid, sodium lauryl sulphate
What is a anti-adherent?
prevents sticking between the powder and the punches of the die
= magnesium stearate, talc, starch, cellulose
What are the methods of tablet formulation?
compression
- single punch press
- rotary press
freeze dried/moulded
How does the single punch press work?
upper punch is raised
lower punch drops to create a cavity in the die
hopper shoe swings across and granules fall into the die
upper punch descends to crush the granules
upper punch retracts and the lower punch moves up to eject the tablet
hopper shoe swings across to push aside the tablet as the lower punch descends
die is again filled by the hopper shoe
What are the advantages and disadvantages of single punch press?
advantages
- easy to operate
- ideal for small batch production
disadvantages
- weight and dose variation
- weight is controlled by volume
What are the advantages and disadvantages of rotary press?
advantages
- high productivity with minimal labour
- powder filled capacity can be controlled automatically
- allows independent control of weight and hardness
disadvantages
- capping = removal of the top layer or bottom
- sticking = material may stick to the machine surface
- picking = product sticks to the letters/logos on the punches
What can the shell of capsule be made out of?
gelatin - obtained from the partial hydrolysis of collagen from animal sources
water
sugar
