Pharmacology Lab Dosage Forms PDF

Pharmacology lab Third stage College of dentistry Dosage Forms Assist. Lec. Huda Abdul Baki Dosage Forms (DFs) Dosage Forms are the means that used to deliver a drug molecule to the action site in the biological system to get optimum desirable effect with lowest adverse reaction. ...

Pharmacology lab Third stage College of dentistry Dosage Forms Assist. Lec. Huda Abdul Baki Dosage Forms (DFs) Dosage Forms are the means that used to deliver a drug molecule to the action site in the biological system to get optimum desirable effect with lowest adverse reaction.  DFs can be classified according to the route of administration or to the physical form. Physical form classification includes: 1- Solid (tablets, capsules, powder, etc.) 2- Semisolid (ointments, creams, pastes) 3- Liquid (suspension, solutions) 4- Gaseous (aerosols) The aims for preparing different dosage forms are embodied in 1. Getting an accurate dose. 2. Protecting the drug from gastric juice. 3. Masking taste and odour. 4. Placement of drugs within body tissues. 5. Sustaining and controlling a drug release. 6. Optimising a drug action. 7. Inserting of drugs into body cavities (e.g. rectally). Selection of a suitable dosage form depends on: 1- The physico-chemical properties of a drug (e.g. acid or base). 2- Site of desired drug action (local or systemic). 3- The required onset of response (fast or slow response). 4- Rate and extent of a drug absorption (from different routes). 5- State of the patient (e.g. conscious or not).  Solid Dosage Forms 1- Tablet (tab, tabs): is a hard-compressed unit consisted of the active ingredient, which is the drug, and excipients in predetermined ratio. The excipients can include diluents, binders or granulating agents, glidants (flow aids) and lubricants to ensure efficient tableting, disintegrants to promote tablet break-up in the digestive tract, sweeteners or flavors to enhance taste, and pigments to make the tablets visually attractive Can a tablet be coated? And why? Yes, to Make a tablet smoother and easier to swallow. Make it more resistant to the environment (extending its shelf life). Control the release rate of the active ingredient of the tablet. Enhance the tablet's appearance. Types of tablets: Scored tablets: have indented lines, usually dividing the tablet into two or more equal parts.  Sugar coated tablets: a sugar coat is added to the tablet to mask the unpleasant taste of tablet, e.g. Flu-out. Chewable tablet: They are tablets that can be chewed before swallowing  Enteric coated tablets: have special coating designed to allow tablet to pass through acid in stomach and not dissolve until in alkaline environment of small intestine – this avoids irritating the stomach, e.g. Aspirin. Slow-release tablets: designed to provide continuous, sustained release of a certain drug over time. e.g. voltarin (100 mg) last 24 hours. Caplets (capsule-shaped tablet): elongated shape tablets, which may make it easier for some to swallow. 2- Capsules: Is a gelatin container filled with a medication. A- Hard gelatin capsules: Made by using gelatin and contain dry, powdered ingredients and manufactured in two pieces. B- Soft gelatin capsules: Drug usually in liquid form inside the shell and manufactured in one piece. Effervescent tablets: They are uncoated tablets that generally contain acid substances (citric and tartaric acids) and carbonates or bicarbonates, which react rapidly in the presence of water by releasing carbon dioxide. They are intended to be dissolved or dispersed in water before use providing: A- Very rapid tablet dispersion and dissolution. B- Pleasant tasting carbonated drink 3- Lozenges: Solid preparations formed from sugar base, containing drug and other flavors. They are designed to dissolve slowly in the mouth and release drug topically to the tissues of mouth and throat. E.g. Strepsils *Note: Lozenges should not to be swallowed. 4- Dental cones: Tablets can be applied in an empty-sockets following a tooth extraction in order to prevent the multiplication of pathogenic bacteria as they can contain antibiotic or antiseptic material. 5-Powders: A finely ground form of an active drug. e.g Arestin, which is a tetracycline antibiotic that fights bacteria so can be used together with certain dental procedures to treat periodontitis (gum disease).  6- Granules: Consisting of solid, dry aggregates of powder particles. 7- Suppositories: A solid base of glycerin or cocoa butter containing a drug. Manufactured in appropriate size for rectal and vaginal use. Vaginal suppositories most often used to treat vaginal infections. Rectal suppositories often offer alternate route of administration for patients who are vomiting Semisolid dosage forms 1- Creams: are semisolid emulsions, which is a mixture of water and oil with a predetermined ratio. 2- Ointment: Semi-solid greasy preparations of hydrocarbons (petrolatum, mineral oil, paraffins, synthetic hydrocarbons). Strong emollient that makes it useful in treating dry skin conditions. Contains no water Less skin penetration than cream 3- Paste: is a mixture of powder and ointment. Pastes are less penetrating than ointment. Pastes make particularly good protective barrier when placed on the skin. 4- Gel: Semisolid system consisting of dispersion of small or large molecules in an aqueous liquid vehicle rendered to jelly like by adding gelling agent. Gels on contact with the skin, dry and leave a thin film of active medication. Liquid dosage forms Come mainly in solutions and suspensions which do not require disintegration of the formulation and thus are generally absorbed more readily than solid formulation. - 1.Elixir: is clear sweetened hydro-alcoholic solution. Moreover, flavoring agents can be added to enhance palatability. - 2- Syrups: It is concentrated aqueous solution of a sugar, usually sucrose to which medicaments are added Do not contain alcohol but it may have flavoring agents. They are sweeter and more viscous than elixirs 3- Suspensions: Contain fine and undissolved particles of a drug suspended in a liquid base. These particles will settle to the bottom of the container after prolonged standing. This needs to shake the suspension bottle well before use to evenly distribute the drug particles.  4- Tinctures can be defined as alcoholic preparations containing the active principals of vegetable drugs. It can be topically applied for example tincture of iodine.  5- Emulsion: a suspension of fat particles in a watery base. 6- Lotion: topically applied suspension of an active drug in a water base, usually some skin-moisturizing agent added. e.g. Calamine lotion  7- Injections: is a method of putting liquid into the body, usually with a syringe. There are several methods of injection, including: A- Intravenous injection (IV): It is a liquid administered directly into the bloodstream via a vein. B- Intramuscular (IM) injection is a technique used to deliver a medication deeply into the muscles  C- Subcutaneous (SC) injection: is a method of administering medication. In this type of injection, a short needle is used to inject a drug into the tissue layer between the skin and the muscle Depends on drug diluents, they could be aqueous solution or depot preparations (solid or oil base, from which the drug gradually absorbed by surrounding tissue). Q/ What's the difference between vials and ampoules? A/ Vials usually keep contents sealed in screw caps and can be opened and closed indefinitely. Closed with screw cap or dropper to allow more than one dose to be taken and has a rubber cover to avoid contamination. Ampoules are made up completely of sealed glass and need to be broken to access the material sealed inside. Therefore, ampoules are not reusable  8- Infusion therapy: Involves the administration of medication through a needle or catheter. It consists of diluted solution that contains a readily soluble constituents of crude drugs. 9- Drops: We have different types of drops such as eye, nasal and ear drops. Moreover, we have oral drops, take for example, sodium fluoride oral drops (0.5 mg/mL)  10- Gargles: They are aqueous solutions used in the prevention or treatment of throat infections. Usually, they are prepared in a concentrated solution with directions for the patient to dilute with warm water before use. 11- Mouthwashes: These are similar to gargles but are used for oral hygiene and to treat oral infections. 12- Extracts: These are concentrated preparations containing the active principals of vegetable or animal drugs. Gaseous dosage forms Gaseous dosage forms can be either as liquid or powders, which are packed in a canister that gets released upon applying pressure. The gas inside contains the active ingredient. Valve systems with continuous or limited delivery should be used within the containers. They are used for topical application on skin and as local application into nose, mouth, and lungs Gaseous dosage forms can be packed and dispensed in: 1. Sprays 2. Vaporizer 3. Aerosols 4. Nebulizer or atomizer 5. Inhalers  Liquid sprays: solutions of a drug combined with water or alcohol. Commonly used for topical application. An example is the Anginovage spray which is indicated for prevention and treatment of oropharyngeal conditions.  Inhalers: are solutions, suspensions or emulsion of drugs in a mixture of inert propellants held under pressure in an aerosol dispenser. Usually, used to treat respiratory diseases like asthma. Nebulizer: is a device used to administer medication to people in forms of a liquid mist to the airways. Usually, used to treat respiratory diseases like allergic bronchitis.