Pharmacology: Drug Delivery Systems

Drug Delivery Systems

• The release of API is under the control of the drug delivery system (temporal control)
• Advantages of controlled release: • Avoids fluctuations of plasma drug concentration for better safety and efficacy • Decreased frequency of drug administration (often once daily) for better compliance
• Types of controlled release: • Sustained release (SR) – release of the initial API dose and further prolonged release • Controlled release (CR) – properly controlled (Zero order) release of API

Capsules

• A capsule is a medication in a gelatin container
• Advantage: masks the unpleasant taste of its contents
• Types of capsules: • Hard-shelled capsules (for dry, powdered ingredients) • Soft-shelled capsules (for oils and active ingredients dissolved or suspended in oil)

Lozenges

• Solid preparation consisting of sugar and gum
• Used to medicate the mouth and throat for slow administration of indigestion or cough remedies

Pastilles

• Solid medicated preparations designed to dissolve slowly in the mouth
• Softer than lozenges, with bases made of glycerol and gelatin, or acacia and sugar

Dental Cones

• Tablet form intended to be placed in the empty socket following a tooth extraction
• Prevents the local multiplication of pathogenic bacteria associated with tooth extractions

Pills

• Oral dosage forms consisting of spherical masses prepared from one or more medicaments incorporated with inert excipients

Granules

• Solid, dry aggregates of powder particles often supplied in single-dose sachets
• Some granules are placed on the tongue and swallowed with water, others are intended to be dissolved in water before taking

Powders (Oral)

• Two kinds of powder intended for internal use: • Bulk Powders: multidose preparations consisting of solid, loose, dry particles of varying degrees of fineness • Divided Powders: single-dose presentations of powder (e.g., a small sachet) intended to be issued to the patient as such, to be taken in or with water

Powders for Mixtures

• Mixed powders may be stored in dry form and mixture prepared by the pharmacist when required for dispensing by suspending the powders in the appropriate vehicle

Liquid Preparations

• Solutions are traditionally one of the oldest dosage forms used in the treatment of patients
• Advantages: rapid and high absorption of soluble medicinal products

Topical Dosage Forms

• Lotions: fluid preparations (aqueous) for external application without friction
• Collodion: a solution of nitrocellulose in ether or acetone, sometimes with the addition of alcohols
• Paints: liquids for application to the skin or mucous membranes
• Pressurized dispensers (aerosol sprays): several different types of pharmaceutical product may be packaged in pressurized dispensers

Vaginal Dosage Forms

• Vaginal capsules: similar to soft gelatin oral capsules, differing only in size and shape
• Vaginal ring: 'doughnut-shaped' polymeric drug delivery devices designed to provide controlled release of drugs to the vagina over extended periods of time
• Douche: a device used to introduce a stream of water into the body cavity for medical or hygienic reasons
• Intrauterine device (IUD): a birth control device placed in the uterus, also known as a coil

Parenteral Dosage Forms

• Injections: infusion methods of putting liquid into the body, usually with a hollow needle and syringe
• Types of injections: • Intravenous injection: liquid administered directly into the bloodstream via a vein

Inhaled Dosage Forms

• Nebulizer or atomizer: a device used to administer medication to people in forms of a liquid mist to the airways
• Aerosol particles: size determines the speed of penetration into the respiratory tract

Ophthalmic Dosage Forms

• Eye drops: saline-containing drops used as a vehicle to administer medication in the eye
• Ophthalmic ointment and gel: sterile semi-solid preparations intended for application to the conjunctiva or eyelid margin

Otic Dosage Forms

• Ear drops: solutions, suspensions, or emulsions of drugs instilled into the ear with a dropper
• Used to treat or prevent ear infections, especially infections of the outer ear and ear canal

This quiz tests your knowledge of drug delivery systems, including temporal control, advantages, and types of release such as sustained release and controlled release.