University:
American Career College
Course:
NURS115 | Intermediate Medical
Academic year:

2021
Views:

346

Pages:

49
Author:

Opfer8fg

Drug  A drug may be defined as an agent intended for use in the diagnosis, treatment, cure or prevention of disease. The nature & sources of drugs  Minerals- MgSo4, liquid paraffin  Animals- Insulin, Thyroid hormones  Plants- Morphine, quinine  Synthetic- Aspirin, sulfonamides  Microorganisms- penicillin, other antibiotics  Genetic engineering- human insulin, human GH Why do we need different drug formulations?  The drug active component can not be used directly (in powder form!)  Patient receiving proper dose (not easy to measure)  Easier to carry on pocket or bag.  Patient needs different formulations in various conditions (unconsciousness, vomiting, child,…)  Stability of the drug is important (light, oxygen, humidity)  Some drugs are very unstable  Emergency situation Route Of Administration  Oral  Parenteral (Injection into body cavity)  Transdermal (through skin)  Nasal  Ophthalmic  Otic  Rectal & vaginal Route of administration  Systemic administration  Local (topical) administration Systemic administration  Oral  Injections  Sublingual, buccal  Rectal-NSAIDs  Inhalational  Through skin-transdermal patches  Implants Topical administration  Skin- skin patches  Ophthalmic  Nasal  otic  Vaginal  Rectal- antihemorrhoids, laxatives  Broncial  Uretheral  Local injections (knee, shoulder, spinal cord) Physical classification of drug formulations  Solid  Semi-solid  Liquid  Gas Solid Oral Dosage Forms Powders Granules Capsules Tablets Controlled -release dosage forms Suppositories Transdermal patches Semi-Solid dosage Forms  Cream  Ointment  Gel  Paste Liquid dosage Forms  Homogen  Solutions     Oral External use Injectable Ophthalmic  Dispersed   Suspension Emulsions Gas dosage Forms  Homogen- medical gases  Dispersed   Liquid particles in gas Solid particles in gas Oral Route Advantage  Comfort and convenience  Accidental overdosing  Drug taken orally is swallowed  Systemic effect  Local action Oral Route  Solid oral dosage forms  Liquid oral dosage forms Powders  Bulk powders  Divided powders- sachet Granules Capsules  A common formulation of drug   Hard gelatin capsules (HGC) Soft gelatin capsules (SGC)  Might be transparent or opaque  Might be filled with powder, granule or liquid Tablets  Very common formulation.  Different shapes (circle, square, …)  Scored or double scored (can be easily divided)  Might be coated or not. Type of tablets         Compressed tablets (C.T.) Multiple compressed tablets (M.C.T.) Sugar-coated tablets (S.C.T.) Film- coated tablets (F.C.T.) Enteric- coated tablets (E.C.T.) Buccal or sublingual tablets Chewable tablets Effervescent tablets- joshan Controlled -release dosage forms Rate- controlled release (CR) Sustained-release or slow release (SR) Extended-release (XR) Repeat action Delayed release Characteristics  They exhibit neither very slow nor very fast rates of absorption and excretion.  They are uniformly absorbed from the gastrointestinal tract.  They are administered small doses.  They possess a good margin of safety.  They are used in the treatment of chronic rather than acute conditions. Pharmaceutical Technology  Coated beads or granules.  Micro encapsulation.  Embedding drug in slowly eroding matrix.  Two- layered tablets.  Embedding drug in inert plastic matrix. Liquid Oral Dosage Forms Fast effect, no dissolution required Oral solutions Oral suspensions Emulsion Liquid Oral Dosage Forms Solutions Solutions are liquid preparations that contain one or more chemical substances (a solid, a liquid , and less frequently a gas) dissolved in a suitable solvent Oral injection topical Oral Solutions Syrup  Sweet, viscous solution Elixir  Hydroalcoholic solution, clear and less sweet Oral Suspensions Liquid preparations containing undissolved drug distributed throughout, a vehicle The substance distributed is dispersed phase The vehicle is termed the dispersing phase or dispersed medium Together they produce a dispersed system Solid in liquid dispersion Example: antacids Oral Suspensions • More stable than solutions • Suitable for patients with difficulty in swallowing tablet and capsule. Two forms: Ready-to-use form (oral suspension) Dry powders form (for oral suspension) Emulsions  Emulsion - Small globules of a liquid distributed throughout a vehicle in which it is immiscible  w/o- for external use  o/w- fish oil, cascara oil  Liquid in liquid dispersion  Example: intralipid An emulsifier decreases surface activity between two phases Lotions  In the form of suspension or emulsion  For external use only  Aqueous base  Examples: corticosteroids, antifungals, anti acne, skin softners Parenteral  Injections - Injections are sterile, pyrogen-free preparations administered parenterally  Rapid drug action is desired.  When the patient unable to use the drug by the oral route.  When the drug itself is ineffective by other routes. Parenteral  Small volume parenteral - Ampoule - Vial  Large volume parenteral (LVP)  Pellets or implants Vial  Vial  Solid  lyophilized powder  Liquid    Solutions Suspensions emulsions Ampoule  Sterile  Once opened can not keep the remainder for future use  Made in different volumes Other injections  Prefilled syringe  Insulin pen Advantages and disadvantages Advantages:  When oral can not be used  The active component is unstable  Patient is unconscious or vomiting  Fast effect is desired Disadvantages:  Painful  Disinfection required  Expert needed  Sometimes serious adverse effect of drug Transdermal  Are used through the skin Transdermal Dosage Forms  Ointments  Creams (W/O or O/W)  Gels, pastes, plasters  Transdermal drug delivery systems Transdermal Drug Delivery Systems (TDDSs)  Deliver the drug substances at a controlled rate, to the intact skin of patients, for absorption into the systemic circulation Technology of Transdermal Drug Delivery Systems  Membrane-controlled system - Those that control the rate of drug delivery to the skin  Monolithic system - Those that allow the skin to control the rate of drug absorption Nasal, Ophthalmic, Otic Dosage forms used with eye, ear, nose, Nasal Preparations  Local, systemic  Solutions, spray, and rarely gel  Aqueous, isotonic, with preservative  Rebound congestion  For peptides, and polypeptides Ophthalmic Preparations Aqueous solutions and suspensions, ophthalmic ointments, ophthalmic inserts Sterility, preservation, isotonicity, buffering, viscosity Normal volume of tear 7l Non-blinking eye 30l Blinking eye 10l Ear Preparations      Otic or aural preparation Solution, suspension, and ointment Cerumen (wax)- Removing preparations Synthetic surfactants in glycerin or in propylene glycol Antibiotics in glycerin or in propylene glycol with topical anesthetics, and analgesic Aerosols are pressurized dosage forms containing one or more active ingredients, which emit a fine dispersion of liquid and/or solid materials in a gaseous medium Advantages of the Aerosol  Easily withdrawn without contamination  Protection from O2, moisture, light and keep sterility  Topical application without touching  Proper formulation and valve control  Clean application Suppository  Are solid dosage forms, for insertion into body orifices where they melt, soften, or dissolve and exert localized or systemic effect  Rectal  Vaginal  Urethral Novel drug delivery systems  Targeted delivery  Controlled drug delivery  Liposomes  Nanodrugs