The various types of tablets are described as follows

1. Conventional Compressed Tablets – Compressed tablets are solid dosage forms prepared by compaction of a formulation containing a drug and certain excipients selected to aid in processing and to improve product properties. The majority of tablets used today in clinical practice are conventional compressed tablets. Examples: Tylenols tablet, metformin tablet.
2. Molded Tablets – Molded tablets are prepared by molding rather than by
   compression. They are very soft and disintegrate quickly. One example of molded tablets is tablet triturates. Examples: Nitroglycerin tablet triturates.
3. Buccal Tablets – Buccal tablets are flat, oval tablets intended to be dissolved in the buccal pouch for absorption through the oral mucosa. Example: Fentanyl buccal tablet.
4. Sublingual Tablets – These are flat, oval tablets intended placed beneath the tongue. Example: Glyceryl trinitrate sublingual tablet
5. Chewable Tablets – Chewable tablets are chewed in the mouth before swallowing. They are not intended to be swallowed intact and are used when a faster rate of dissolution and/or buccal absorption is desired. Examples: Pepcid chewable tablet, chewable aspirin tablet.
6. Effervescent Tablets – Effervescent tablets are uncoated tablets produced from compression of effervescence granules that contain an organic acid (citric) and sodium bicarbonate in addition to the medicinal substance. When such tablets are placed in water, they react rapidly by releasing carbon dioxide which acts as a disintegrator to produce either a drug suspension or an aqueous solution. Example: Alka-Seltzert tablet, Ca C1000 Sandoz effervescent tablet (Novartis).
7. Lozenges and Troches – Lozenges and troches are slow dissolving tablets intended to be sucked and held in the mouth, where they exert a local effect in the mouth or throat. Examples: Clotrimazole troches, Chloraseptics^® lozenges, Nicorettes^® lozenges.
8. Multiple Compressed Tablets – Multiple compressed tablets are tablets that are composed of two or more layers. They are also called multi-compressed tablets and are designed to enable the separation of incompatible ingredients or make sustained-release products, or they are merely designed for appearance. There are three classes of multiple compressed tablets: layered tablets, inlay tablets, and compression-coated tablets. Examples: Phenylephedrine HCL, ascorbic acid with acetaminophen.
9. Sugar-Coated Tablets – Sugar-coated tablets are conventional compressed tablets that are coated with successive coats of sugar solution with or without a color to produce elegant, glossy, and easy-to-swallow tablets for oral use. Example: Perphenazine tablet, sugar-coated
10. Enteric-Coated Tablets – Enteric-coated tablets are conventionally compressed tablets that have delayed-release properties. They are coated with a polymer that does not dissolve in the acidic condition of the stomach but readily dissolves in the alkaline pH of the small intestine. Examples: Enteric-coated aspirin tablet, naproxen enteric-coated tablet.
11. Film-Coated Tablets – Film-coated tablets are compressed tablets coated with a colored polymeric coating (e.g., hydroxypropylmethyl cellulose, hydroxypropyl cellulose, and
    Eudragits E100, etc) that forms a thin skin-like film around the tablet core.  Example: Glyburide/metformin (5 mg/500 mg) film-coated tablets.
12. Tablet Triturates – These are small, usually cylindrical, molded, or compressed tablets containing small amounts of usually potent drugs mixed with a combination of sucrose and lactose or any suitable diluent. Example: NTG tablets.
13. Immediate-Release Tablets – Immediate-release (IR) tablets are tablets designed to start releasing the drug as soon as they come in contact with the tablet disintegrating/dissolving fluid. This is the most common type of tablet and examples include chewable, effervescent, sublingual, and buccal tablets.
14. Sustained-Release Tablets – Sustained-release (SR) tablets sometimes called extended-release (XR) tablets are tablets designed to release their medication in a predetermined manner over a prolonged period of time. Example: Wellbutrin SRs (bupropion hydrochloride) tablet.
15. Controlled-Release Tablets – Controlled-release (CR) tablets are tablets designed to release the drug at a predetermined and controlled rate. Example: Oxycodone HCl CR tablet (analgesic).
16. Delayed-Release Tablets – Delayed-release (DR) tablets are designed to delay the release of the drug from the time it first comes in contact with the tablet disintegrating/ dissolving fluid. Example: Omeprazole DR tablet.
17. Rapidly Dissolving Tablets – Rapidly dissolving tablets also called rapid release tablet, rapidly disintegrating tablets, orally-dispersible tablets, quick disintegrating tablets, mouth dissolving tablets, fast disintegrating tablets, fast-dissolving tablets, rapid-dissolving tablets, or porous tablets are characterized by disintegrating or dissolving in the mouth within 1 minute, some within 10 seconds, leaving an easy-to-swallow residue. Example: Clarinex Reditabs (desloratadine).
18. Hypodermic Tablets – Hypodermic tablets are soft, readily soluble tablets that were originally used by physicians in extemporaneous preparation of parenteral solutions. Example: Dilaudid – Dihydromorphinone HCl.
19. Dispensing Tablets – Dispensing tablets also referred to as compounding tablets are tablets supplied primarily as a convenience for extemporaneous compounding. Example: silver potentiate, bichloride of mercury merbromin, and quaternary ammonium compounds.
20. Vaginal Tablets – Vaginal tablets or vaginal inserts are ovoid- or pear-shaped uncoated conventional compressed tablets that are inserted into the vagina using a plastic inserter. Examples: Vagifems (estradiol vaginal tablets), nystatin vaginal tablets, USP.
21. Gelatin-Coated Tablets – Gelatin-coated tablets are compressed tablets coated with either one or two-toned color gelatin. Example: gelatin-coated hydrochlorothiazide tablet.

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