L12- Formulation Of Analgesics Flashcards
Lidocaine used for
Toothache
Ideal analgesic formulation
Should be effective against a broad range of pain types, eg different stages of pain and typses like Nociceptive, psychogenic and neuropathic
Should have a rapid onset and controllable duration
Easy to administer
No side effects
Nociceptive pain
Physical damage to body
Psychogenic
Caused by psychological factors eg depression
Neuropathic
Pain affecting somatosensory nervous system
What influences the selection of dose and route of administration
Severity and localisation of the pain
Advantages and disadvantages of tablet
Convenient, accurate dosing, easy to take
Poor bioavailability, local irritants effects and harm caused to GI mucosa
Capsules a&ds
Controlled release of drug, good patient complience, accurate dosing
Larger in size, susceptible to moisture, ingredient and shell interacts, difficult to fill accurately. Have to be swallowed whole
Caplets
Faster dissolution rate than tablets or capsules, can be used for drugs usually as a solution or suspension
Less convenient to carry and self administer as liquid preparations than tablets or capsules, unpleasant taste not masked
Suspension a&ds
Convenient when drug isn’t soluble in water and non-aqueous solvent can’t be used.
Insoluble solids act as a reservoir and continuously supply the drug into solution.
Higher bioavailability that’ll tablets/capsules
Masks unpleasant taste
Sedimentation of solids, microbial contamination, not precise dose
Syrup a&d
Masks unpleasant taste,thick=soothes throat, no alcohol, easy to adjust dose for children
Loss of potency faster than solids,incompatibilities between substances, bacteria and mould growth, contains sugar, inaccurate dose on spoon
Suppository a&ds
Absorption not affected by GI
Avoids FPM
Good when vomiting
Quick response
Irritation of mucus membrane
Small surface area
Less fluid content than ingestine(dissolution affected)
Interrupted by bowel movements
Topical administration
Application of a formulation to the skin to treat a local disorder (drug stays on skin)
Transdermal administration
Application of formulation to skin to deliver drug to systemic circulation
Gels/gel patch a&d (topical)
Avoids serious adverse effects of NSAIDS
Therapeutic conc in localized tissue
Avoid FPM
Difficult to formulate
Must have aqueous and lipid solubility
Variation of skin permeability
Patches a&ds (transdermal)
Avoid pH variations in GI
Avoids FPM
Removed quick and easily in case of adverse reactions
Long duration of action
Few molecules have the physiochemical and therapeutic properties for sustained transdermal delivery
Matrix patch example
Mezolar, osmanil
Reservoir patch
Fentalis, tilofyl (contains drug reservoir and rate controooijg membrane)
