L51 Role Of Excipients Flashcards
(35 cards)
Why are drugs not administered as pure substances?
Factors include:
* Dose
* Taste- bitter, helped with film coating
* Solubility
* Bioavailability
* Stability
* Control rate of absorption
* Allow administration via specific routes
* Handling, transportation, and marketing
All of these factors can be controlled with the use of excipients and formulation science.
What is the role of excipients in solid dosage forms?
Excipients help to:
* Aid processing during manufacture
* Protect, support, or enhance stability, bioavailability, or acceptability
* Assist in product identification
* Enhance overall safety and effectiveness during storage and use
Excipients are all the other components of a formulation other than the active drug.
What is an excipient?
All the other components of a formulation other than the active drug
* should be chemically and physiologically inhert
Each component requires an appropriate evaluation for safety and should be chemically and physiologically inert.
What is the typical dose of aspirin in a tablet?
300 mg API
What is the dose of Ethinyl estradiol compared to aspirin?
0.035 mg, which is 1/8000 of the dose of aspirin
What are some common pharmaceutical excipients?
Examples include:
* Lactose
* Micro Crystalline Cellulose (Diluent)
* Sodium Bicarbonate (Effervescent excipient)
* Magnesium Stearate (Lubricant)
* Colloidal Silicon Dioxide
These excipients play various roles in tablet formulation.
What is the disadvantage of using magnesium stearate as a lubricant?
It can decrease disintegration time, drug dissolution, and weaken bonding forces, leading to soft tablets.
*reduction due to its hydrophobic nature
*incompatible with many drugs
What is the role of disintegrants in tablet formulations?
To promote break up of tablets in vivo and enhance drug dissolution
* rapidly dissintegrates to increase SA of particulates and promote rapid release of drug
What is the most common disintegrant used?
Starch
What are super disintegrants?
Modified starch (Sodium starch glycollate) with rapid swelling and much more effective at lower concentrations
* however more hydgroscopic
Fill in the blank: The primary substance employed as a diluent is _______.
lactose, pleasant tast, rapidly dissolves and not hydroscopic
What is the function of glidants in tablet formulations?
To improve the flow properties of granules by reducing inter-particulate friction
What is the most commonly used glidant?
Fumed silica
What are binding agents used for in tablet formulations?
To bind powders together in the wet granulation process or granules during direct compression
What is a common binding agent in tablet formulations?
Polyvinylpyrrolidone (PVP) and gelatin
What effect do tablet lubricants have on drug dissolution?
They can adversely affect rates of drug dissolution
True or False: Magnesium stearate is the most popular lubricant in tabletting.
True
What is the effect of adding colloidal silica to tablet formulations?
It can dramatically improve the flowability of granules when added in < 0.1% w/w
What is the purpose of using adsorbents in tablet formulations?
To hold quantities of fluids in an apparently dry state
What are some examples of adsorbents used in tablet formulations?
Fumed silica, microcrystalline cellulose, kaolin, magnesium carbonate
What are the common modes of action of disintegrants?
Swelling, porosity and capillary action, deformation, gas production
What is the role of sodium bicarbonate in Panadol ActiFast?
*Increases rate of tablet disintegration and dissolution, and gastric emptying so faster absorption
*amount of sodium bicarb in 2 tablets of actifast are needed per dose for an effect thereofre if u take one tablet or with less than 100ml of water the rate of absorption will be the same as for standard panadol
What is the effect of moisture on microcrystalline cellulose?
Sensitive to moisture, with a 5% moisture uptake
What is the function of effervescent excipients?
To promote disintegration and dissolution of tablets
