Tablets Flashcards
Describe the plasma concentration over time graph ?
- Y-axis is plasma concentration
- X is time
- T max = time of maximum concentration
- C max = max conc of drug
what is the therapeutic window ?
- from Cmax to minimum effective concentration
what are advantages of taking tablets ?
- convenient
- longer shelf life than liquid
- cheap
- precise dosing
what are the different types of tablets ?
- buccal
- effervescent
- dispersible
- disintergrating
- modified release
- sublingual
what kind of release do disintegrating tablets give ?
- immediate release
- eg. gastro-resistant tablets
what are the 3 types of modified release tablets ?
- prolonged = slowly at constant rate
- delayed = released after some time
- pulsatile = drug is released in 2 or more pulses
what are dispersible tablets ?
- disintegrate in water before administration
what are effervescent tablets ?
- uncoated tablets, dissolved in water before administration
- bubble
- faster drug absorption
what are sublingual and buccal tablets ?
- sublingual = under tounge
- buccal = buccal cavity = side of cheek
what are lozenges ?
- hard, solid
- dissolve in mouth slowly when sucked
what are the 3 main stages in tablet formation ?
- die filling
- tablet formation
- tablet ejection
what is die filling ?
- powder flows down from a hopper into the die
what happens during tablet formation ?
- upper punch comes down
- compresses powder into tablets
- upper punch moves up after compression
what happens during tablet ejection ?
- lower punch rises to eject tablet
what are the 6 tablet excipients ?
- Filler
- anti-adherent
- glidant
- disintegrant
- binder
- lubricant
why is filler used as an excipient ?
- increase bulk
- eg. lactose
why is disintegrant used as an excipient ?
- allows tablet to break up into small fragments in a liquid
why is binder used as an excipient ?
- adhesive
- ensures they can be formed with required mechanical strength
why is gildant used as an excipient ?
- improves powder flow-ability by reducing cohesion
why is lubricant used as an excipient ?
- reduces friction between ingredients and machine wall
why is anti-adherent used as an excipient ?
- reduces adhesion between powder and punch
