Pharmaceutical Solid Dosage Form

          Solid dosage form such as tablets, capsules, have many advantages over other types: greater stability, less risk of chemical interaction between different medications, smaller bulk, accurate dosage,
and ease of production. 

I. TABLETS: Tablets are solid dosage forms usually obtained by single or multiple compressions of powders or granules. Tablets are normally right circular solid cylinders, the end surfaces of which are flat or convex and the edges of which may be beveled. They may have lines or break-marks (scoring), symbols or other markings.

     1. Uncoated tablets:  compressed tablet or core tablet formed by compression and contain no special coating. They are made from active ingredient in combination with excipients such as binders, diluents, etc

Example: Analgin, Paracetamol, Bactrim, etc

     2. Sugar-coated tablets: are smooth, round or oval compressed tablets containing sugar coatings. Sugar coating provides both protection and sweet taste but the coating operations take a long time. Example: Neocodion, Paderyl, Aphatyl, Spasfon etc.

     3. Film-coated tablets: are compressed tablets which are covered with a thin layer or a film of polymeric substances to protect their contents from moisture or to mask the taste of the ingredients.

Example: Ibuprofen

   4. Modified release tablet: Modified-release tablets are coated, uncoated or matrix tablets containing excipients or prepared by procedures which, separately or together, are designed to modify the rate, the place or the time of release of the active ingredient(s) in the gastrointestinal tract.

          -Sustained-release tablets (Extended/Controlled/Prolonged-release): Sustained-release    tablets are designed to slow the rate of release of the active ingredient(s) in the           gastrointestinal tract.

                Example: Nifedipine

      -Delayed-release tablets (Entered-coated/Gastro-resistant tablets): are coated with          substances that resist solution in gastric fluid but            disintegrate in the alkaline contents of           the intestine. Enteric coating is used for medicines with a gastric irritant action, for         medicines which are unstable in the acid medium of the             gastric contents or if the         medicine should act on the intestine.

            Example: Aspirin 81mg

    5. Effervescent tablets: Effervescent tablets are uncoated tablets generally containing acid substances and carbonates or hydrogen carbonates that react rapidly in the presence of water to release carbon dioxide. They are intended to be dissolved or dispersed in water before administration.

Example: Efferalgan Vitamin C, Berroca, Suppradine, etc

     6. Chewable tablets: Chewable tablets are usually uncoated. They are intended to be chewed before being swallowed; however, where indicated on the label, they may be swallowed whole instead. They should be hard and large which difficult to swallow.

Example: Maalox, Amoxicillin chewable, Zentel, etc

     7. Lozenge tablets (Trouche): Tablets containing palatable flavoring, indicated for a local (often soothing) effect on the throat and mouth. They are placed in the mouth where they slowly dissolve, liberating the active ingredient. The drug involved can be antiseptic, local anesthetic, antibiotic, or antitussive.

Example: Lysopaine, Horf, Strepsil, Wood, Zecuf, etc

       - Patient is advised not to swallow a lozenge; it should be allowed to slowly dissolve in the             mouth.

         - Patient is also advised not to drink liquids for approximately 15 minutes after administration, 

            to prevent washing of the lozenge contents from throat or mouth.

    8. Sublingual tablets: Medicine is placed under the tongue and allows dissolving. It is absorbed into the circulation and provides the systemic effects. This medication form is suitable for the active ingredients which is destroyed or unstable in the gastrointestinal fluids.  

Example: Nitroglycerin

II. CAPSULES: are solid dosage forms in which the drug substance is enclosed in either a hard or soft soluble container of suitable form of gelatin. They are intended to mask the smell and taste of the drug substances. Capsules are tasteless, easily administered and some patients prefer them to the tablets. They are of various shapes and sizes and contain a single dose of one or more active ingredients.

      1. Hard Gelatin Capsules: Hard capsules have shells consisting of two prefabricated cylindrical sections that fit together. One end of each section is shorter, larger rounded, and closed (cap) and the other is open, longer and smaller (body). The contents of hard capsules are usually in solid form (powder or granules).

Example: Amoxicillin, Ampicillin, Cephalexin, etc

     2. Soft Gelatin Capsules: Soft capsules have thicker shells than hard capsules and antimicrobial preservatives are usually added. The shells are of one piece and various shapes. They may be round, oval and oblong. The contents of soft capsules are usually solutions or suspensions of the active ingredient(s) in non-aqueous liquids.

Example: Vitamin E, Vitamin A, Eugica, etc

     3. Modified-Release Capsules: Modified-release capsules are hard or soft capsules in which the contents or the shell or both contain excipients or are prepared by special procedures such as micro-encapsulation which, separately or together, are designed to modify the rate, place or time of release of the active ingredient(s) in the gastrointestinal tract.

           -Sustained-release capsules (Extended/Prolonged-release capsule): Sustained-release       capsules are designed to slow the rate of release of the active ingredient(s) in the           gastrointestinal tract.

            Example: Cardene SR (nicardipine)

           

            -Delayed-release capsules (Enteric/Gastro-resistant capsule): Delayed-release capsules are          hard or soft capsules prepared in such a manner that either the shell or the contents resist the     action of gastric fluid but release the active ingredient(s) in the presence of intestinal fluid.

            Example: Casprin, Esomeprazole

III. PILLS: Are small, round dosage forms for oral administration which are prepared by the pharmacist. They are rarely prescribed today. The powdered ingredients are mixed together with binding agents. The pill mass is rolled into spheres and coated with talc, gelatin, or sugar.

Example: Oral contraceptive pills (Ok, i-Pill, Anlitin, Yasmine, Diane 35)

IV. ORAL POWDER: Oral powders are preparations consisting of solid, loose, dry particles of

varying degrees of fineness. They contain one or more active ingredients, with or without excipients

and, if necessary, authorized colouring matter and flavouring substances. They are generally administered in or with water or another suitable liquid. They may also be swallowed directly. They are presented as single-dose or multidose preparations. Each dose of a single-dose powder is enclosed in an individual container, for example a packet, a sachet or a vial. Multidose oral powders require the provision of a measuring device capable of delivering the quantity prescribed.

Example: Clamoxyl 250mg, Dolipran  powder, Smecta, etc

V. GRANULES: Are dosage forms related to powders. They are particularly suitable for the preparation of solutions or mixtures of medicines.

Example: Montiget, Biorrhee, etc.

  

References: Essential Pharmacology for Health Occupations, 5TH EDITION,  RUTH WOODRAW