Drug Formulations Flashcards
Orally Taken Medications
Classifications
Liquids
Tablets
Capsules
Powders
Orally Taken Medications
Liquids
Solutions: dissolved in water
Syrup: drugs in homogenous sugar based solutions
Elixir: dissolved in alcohol, sweetened
Tincture: alcoholic extract, not sweetened
Suspension: fine drug particles suspended in liquid base
Tendency for drug to settle at bottom-> shake!
Oil/emulsion: liquid in liquid. Unpleasant tast
Ex: Castor oil
Oil in water emulsion
Reach skin surface
Water in oil emulsion
out phase is lipophilic-> can reach deeper
Orally Taken Medications
Tablets
Discs containing one or more drugs
Created by compressing granulated powder
+ Apects
convenient, economical, accurate dose, portable
Components
Drug
Binder (to stick ingredients together)
Disintegrator (ex starch-> swells in + of fluids)
Lubricant (for prod. purposes)
Other (sugar, dyes)
Orally Taken Medications
Tablets
–> Special Tablet Formulations: Coated Tablets
Sugar Coated (dragees): taste better, prevent
disintegration in mouth
Enteric Coated: if stomach pH may destroy meds
Dissolve in alkaline pH of duodenum
Also protects mucosal lining of stomach
Sustained Release: drug release slowly and gradually
Stable blood levels over longer period
Needed if short T1/2
Follows 0 Order Kinetics
Chewable Tablets: better dissolution in gastric cavity
Example: Antacids
Good for patients with difficulties swallowing
Orally Taken Medications
Tablets
--> Special Tablet Formulations
OROS
Sublingual
Buccal
Oral Osmotic Therapeutic System (OROS)
Outer membrane is semi permeable
Water in GIT--> tablet; gap produced; dissolved drug
released
Also slow releasing
Sublingual Tablets
Rapid absorption–> sup. vena cava
Avoid 1st pass metabolism
Buccal Tablets
Drug absorbed via oral mucosa: directly enters
systemic circulation
Orally Taken Medications
Capsules
(Gelatine) cases used to enclose medications
Powders, granules, liquids
Should be stored in cool places
Capsules usually dissolve in stomach
Microcapsule: Each particle is individually coated
Hard Gelatine
Cont. drug as solid
Can be opened
Soft Gelatine
Cont. drugs: liquid or semiliquids
Completely sealed
Useful if drug is not water soluble
Transdermal Medications
Transdermal Patches
Contain steady supply of lipophilic compounds
Highly potent
Absorbed directly into blood stream-> no 1st pass
Greater bioavail. than oral preps
Reservoir Controlled
Active ingredient located within solution or suspension
Layers: backing, reservoir, rate cont. membrane,
adhesive
Matrix Controlled
Solution or suspension inside polymer or cotton pad in
direct contact with skin.
Layers: backing, adhesive cont. drug, release liner
Advantage: thinner
Examples
Oestrogen
Nitrates
Analgesics
Vaginal Medications
Creams, foams, jellies, solutions for irrigation, ointments, suppositories, tablets.
Used to treat local irritations or infections, contraceptives, local hormone props during menopause
Fewer SE than systemics
Rectal Medications
Admin when oral route not possible or CI
Ex: unconscious, vomiting, babies, drug is harmful for
gastric mucosa, local effects desired
Suppositories
Vehicles: cocoa butter, glycerinated gelatine
Melt at body temp–> release drug
Systemic effect: absorption in unpredictable and erratic
DON’T split in half
–> Liver via portal system
CI: inflamed or irritated rectum; diarrhoea
Enema
Ophthalmic Medications
Uses: diagnosis, treatment, prevention
Indications: eye infection, inflammations, glaucoma (ex-> pilocarpine), diagnosis
Eye drops: Solutions, suspensions Ointments Local injections Transconjunctival patches (pilocarpine ex) Local injections
STERILE!
Vehicle is sterile
Isotonic with tear
Can by isohydric (= pH with tear)
Sterile caster oil for oily eye drops
Can use benzalkonium to maintain sterility
Individual usage for each eye to prevent cross infection
Otic Medications
Liquid–> external auditory canal
To treat inflammations, infections and other internal and external ear issues.
Softening agents: for removal of ear wax
If ruptured TM/ drainage from canal: use STERILE tech!
Nasal Medications
Nasal conjestion
Allergic or inflammatory conditions
–> Nasal sprays of drops
Vehicle: high viscosity solvent for longer action
May cause systemic effects; some drugs admin this way to achieve systemic effects ex vasopressin, calcitonin
Peptides: short T1/2; not absorbed from GIT
Other examples of drugs:
Oxametazoline
Nephazoline
Topical Cutaneous Medications
Lotions
Ointments, creams
Solutions, soaps, shampoos
Uses: Local treatment Bacterial or fungal infections Wounds Burns Dermatitis Rash
STERILE if lesions +
Vehicle
Water or oil based dep on solubility of compound and
req. depth of penetration
Parenteral Medications
Not taken via digestive system
For local effects
intraarterial
intracardiac
intradermal
For systemic effects
subcutaneous (sustained effect; factors influencing SC
blood flow ex oedema, shock also influence absorp;
can’t be used for irritating meds; concentrated drugs
can’t be admin this route as –> abscess)
IM (faster than SC; for concentrated, ex VitB12; can be
prepped for slower absorption-> sustained action.
NOT given IV as danger for emboli formation)
IV (for immed action; quick and predictable blood level;
infusion is best way to maintain stable th blood level)
Intraosseal
In emergency if patient unconscious and vessel can’t be
found (ex in shock)
Compared to oral admin
More rapid onset of action
Higher degree of absorption
MUST be STERILE
Inhalation Medications
Example for asthma, chronic bronchitis
Advantages: smaller doses req-> minimal SEs
Pressurised Metered Dose Inhaler
Aerosol created when valve opened-> liquid propelled
via cavitation.
Liquid rapidly evaporated-> small particles (1 microm
diameter) inhaled
Dry Powder Inhaler
Drug: small powder particle
Mixed with larger particles (50-100 microm) of sugar
Increased aerodynamic forces on sugar allow for better
inhalation
Turbulence splits sugar from drug–> sugar is left behind
in oral cavity, throat and device
Drug is absorbed into lungs
Examples
Beta Agonists (Salbutamol, Salmeterol)
M Antagonist (Ipratropium)
Corticosteroids (budeonide)
