Lecture 3 Tablets Flashcards
What distinguishes capsules from tablets?
Tablets are compressed powders.
What are the qualities of a good tablet?
Accurate and uniform of weight, homogeneity, absence of incompatibilities (ex. metal shards from machinery), stability and hardness, ease of disintegration, reasonable size and shape, pleasing appearance, ease of manufacturing, and economy of production.
What are the advantages of tablets?
Accurate dosage/minimum variability, absence of alcohol, concentration variability, elegance, patient acceptance, convenience (light and compact), tamper resistant, low cost, easiest/cheapest to package and ship, production identification is simple, ease of administration, special release profiles possible, suited for large-scale production, and best overall properties of all oral dosage forms.
What are some disadvantages of tablets?
Swallowing, difficult to extemporaneously prepare, some drugs resist compression, poorly wetting drugs, slow-dissolving drugs, intermediate to large dosages/bad odor, and oxygen/moisture-sensitive require coating.
What are the types of tablets are available?
compressed, multiply compressed, sugar-coated, film-coated, gelatin-coated, enteric-coated, buccal and sublingual, effervescent, instantly disintegrating or dissolving, and vaginal tablets.
What are compressed tablets?
Solid dosage forms prepared with suitable excipients and tablet machines capable of exerting great pressure in compacting the powdered or granulated material.
What are the usual tablet excipients?
Diluents or filler, binders or adhesives, disintegrants, antiadherents, lubricants, glidants, and colorants/flavorents(might not be used).
What is the purpose of a diluent?
To add the necessary bulk to a formulation to prepare tablets of the desired size.
What are some examples of diluents?
dibasic calcium phosphate, lactose, sucrose, mannitol, microcrystalline cellulose (also disintegrant), powdered cellulose, and starch.
What is the purpose of a binder or adhesive?
To promote adhesion of the particles.
What are some examples of binders or adhesives?
Acacia, alginic acid, carboxymethylcellulose, gelatin, liquid glucose, methylcellulose, povidone, pregelantinized starch.
What is the purpose of a disintegrant?
To promote breakup of tablets after administration to smaller pieces for ready drug availability.
What are some examples of disintegrants>
microcrystalline cellulose (also diluent), sodium starch glycolate, and starch.
What is the purpose of a glidant?
To improve powder flow.
What are some examples of glidants?
Colloidal silica, cornstarch, and talc.
What is the purpose of a lubricant?
Reduce friction to punch/die during tablet compression and facilitate tablet ejection, improve powder flow properties, decrease adhesion to punch/die, and reduce punch/die wear.
What are some examples of lubricant?
Calcium stearate, magnesium stearate, stearic acid, and zinc stearate (waxy material).
When would you add a lubricant in the mixing process?
At the end because it won’t dissolve if it is blended throughout.
What is the purpose of an antiadherent?
It prevents tablet ingredients from sticking to punches and dies during production.
What are some examples of antiadherent?
Talc and magnesium stearate
Which excipient was most likely added to a tablet formulation with the sole purpose of facilitating powder flow?A. Magnesium stearateB. Microcrystalline celluloseC. Collidal silicaD. Starch
C. Collidal silica
There is a problem with the dissolution of a drug product. What are possible reasons for this and what recommendation do you have to rectify the problem?
Adding the lubricant too early in the production process or not adding enough disintegrant. Add a disintegrant such as starch or add lubricant at the end of production process.
List 5 ways a patient might misuses a tablet dosage form and suggest counseling strategies to dissuade them from doing so.
They could crush/chew the tablet, break the tablet, take with or without food, with alcohol, more or less than prescribed, time of day, route of administration, storage. Make sure they are aware of the proper dosage to take and let them know the side effects of not taking it correctly.
What type of excipient is Collodial Silicone Dioxide and what does it do?
A glidant that helps the powder to flow.
What type of excipient is microcrystalline cellulose and what does it do?
A disintegrant that helps facilitate the break up and distribution once in the body. A diluent that is used to add bulk.
What type of excipient is stearic acid and what does it do?
A lubricant that reduces friction to punch/dye, helps tablet ejection, and improves powder flow.
What are the three ways to prepare compressed tablets?
Wet granulation, dry granulation, and direct compression.
What are the benefits of preparing by wet granulation?
Produces granules with good flow and compression properties (good flow is necessary for high speed presses), produces robust formulations, can be used to distribute low concentrations of drug to achieve acceptable content uniformity.
What are the steps of the wet granulation process?
- Powders dry blended2. Blended material wetted with a binder solution3. Wet milling (optional)4. Granulation dried5. Dried granulation milled to size6. Granules blended with remaining excipients7. Tablet blend compressed