How do effervescent tablets work
Acid base reaction to produce carbon dioxide
Advantages of effervescent tablets
Mask drug taste, drug in solution prior to ingestion, faster onset of action, easier to swallow
Ingredients of effervescent tablets
Active ingredients, buffering agent, soluble organic acid, alkali metal carbonate salt, water soluble binders, water soluble lubricants, artificial and natural sweeteners, flavouring agents, surfactants
How should effervescent tablets be packaged
Tightly closed containers, moisture proof, dry air added when sealed, heavy gauge foil to minimise risk of holes
Testing of effervescent tablets
Hardness, friability, disintegration, dissolution
What are lozenges
Solid preparations designed to dissolve or disintegrate slowly in the mouth, keep drug in contact with oral cavity for extended period
What is the compression of lozenges
Compressed harder than normal tablets so they dissolve/disintegrate slowly
What excipients do hard lozenges not usually have
Disintegrants and preservatives
Base of soft lozenges
Gelatin or PEG
Roles of acacia in soft lozenges
Adds texture and smoothness
Roles of silica gel
Suspending agent- reduce drug settling during cooling process
What are orodisperisble tablets
Uncoated tablets intended to be placed in the mouth where they disperse rapidly before being swallowed
How long should it take orodispersible tablets to disintegrate
3 minutes
Advantages of orodispersible tablets
No need for water, good for swallowing difficulties, sometimes see improved bioavailability
Limitations of orodispersible tablets
Get balance between mechanical strength and rapid disintegration, taste masking problems, high drug loading
Manufacturing techniques for orodispersible tablets
Disintegrant addition, freeze drying/lyophilisation, cotton candy process, sublimation, moulding compression
Locations for transmucosal drug delivery
Oral cavity (mucosal membranes), sublingual (place drug under tongue), buccal (place drug between teeth and cheek)
Why is transmucosal drug delivery used
Absorption from oral mucosa avoids 1st pass metabolism
Limitations/disadvantages of transmucosal drug delivery
Short residence time, small absorption area, taste sensing organ, inadequate permeability for some molecules