Tablets Flashcards
What are tablets
Tablets are solid dosage forms consisting of API and suitable pharmaceutical excipients. They may vary in size , shape , taste, weight, hardness and dissolution
What are advantage of tablets
1) Production aspect
a) Large scale production at low cost
b) Easy and cheap to package and ship
2) User aspect
a) Easy to handle
b) light and most compact
Disadvantages of tablets
Some drugs resist compression into dense compacts
Drugs with poor wetting, slow dissolution, intermediate to large dosages may be difficult or impossible to formulate as a tablet that provide adequate or full drug bioavailability
Bitter taste drugs require encapsulation prior to compression
Types of tablet
1) Compressed tablet
2) Sugar coated tablet
3) Film coated tablet
4) Enteric coated tablet
5) effervescent tablets
6) Chewable tablets
7) Dispersable tablets
8) multilayer tablets
9) buccal tablets
10) implant tablets
Excipients for compressed tablets
Compressed tablets usually contain a number of pharmaceutical adjuncts, known as excipients, in addition to the medicinal substance. The use of appropriate excipients is important in the development of the optimum tablets. Excipients determine the bulk of the final product in dosage forms such as tablet, capsule, etc., the speed of disintegration, rate of dissolution,release of drug, protection against moisture, stability during storage, and compatibility . Excipients should have no bioactivity, no reaction with the drug substance, no effect on the functions of other excipients, and no support of microbiological growth in the product
What are the types of excipients
1) Diluents
2)Binders
3) Lubricants
4) Disintegrators
5) Wetting agents
What are diluters
Diluents increase the volume to a formulation to prepare tablets of the desired size. Widely used fillers are lactose, dextrin, microcrystalline cellu-lose starch, pregelatinized starch, powdered sucrose, and calcium phosphate.
What are binders
Binders promote the adhesion of particles of the formulation. Such adhesion enables preparation of granules and maintains the integrity of the final tablet. As listed in the Table, Commonly used binding agents include: starch, gelatin and sugars (sucrose, glucose, dextrose, and lactose).
What are lubricants
Lubricant is a substance capable of reducing or preventing friction, heat, and wear when introduced as a film between solid surfaces. It works by coating on the surface of particles, and thus preventing adhesion of the tablet material to the dies and punches.
What are Disintegrators
The breakup of the tablets to smaller particles is important for dissolution of the drug and subsequent bioavailability. Disintegrators promote such breakup. To rupture or breakup of tablets, disintegrating agents must swell or expand on exposure to aqueous solution. Thus, the most effective disintegrating agents in most tablet systems are those with the highest wa-ter uptake property. In general, the more hydrophilic, the better disinte-grating agents are therefore highly hydrophilic
What are wetting agents
Water molecules attract each other equally in all directions. Water molecules on the surface, however, can only be pulled into the bulk water by water molecules underneath, since there are no water molecules to pull in the opposite direction. The surface tension of water is strong enough to support the weight of tiny insects such as water striders. The surface ten-sion in action can be visualized by placing a small drop of alcohol on a thin layer of water. Alcohol with lower surface tension mixes with water causing reduction in the surface tension in the local region. Owing to the higher surface tension of water in the neighbor, water is pulled from the alcohol dropped region into the neighbor, and this leads to the formation of a dry spot in the middle of the water layer.
