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53 Cards in this Set
- Front
- Back
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Pharmaceutics
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science that deals with the dosage forms design, includes formulation, manufacturing, stability and effectivness
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dosage form
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physical form drug administered in
-convienient delivery of accurate dose -protection from environment -mask bitterness etc -provide liquid prep for insolubles -reduce freq. drug admin. -localized drug action -avoid gastric destruction |
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drug delivery systems
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means of administering drugs to body in safe efficient reproducible manner
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Classifications by physical form
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solid dosage
molded solid dose semi solid dose piquid dose sterile dose |
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classification--> routes admin
Oral |
most frequent
convenient, effective absorb through GI -ves slow onset absorption variability unconsious cant use |
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Classification route type
Buccal/sublingual |
high blood flow (rapid absorp sublingual)
slow absorp- buccal no destructive GI convientent can be used for unconscious patient -ves bitter sucks dry mouth could swallow load may be limited |
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Classification route type
Rectal vaginal |
rapid absorp
local or systemic effects for rectal for unconscious bypass GI and metab vaginal feels awesome -ve inconvenient absorb variable refridgration |
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Classification route type
topical/ transdermal |
local effect but can do systemic
absorb slow in systemic bypass GI and metab -ve inconvientent absorb variable |
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Classification route type
parental |
local and systemic
fast onset unconscious bypass GI metab large volume via IV -ve not patient friendly cost side effects due to injection |
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Classification route type
pulmonary |
local systemic
fsat onset bypass Gi/ metab -ve may need training low drug load (only good for potent) |
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Classification route type
nasal |
-local systemic
fast onset bypass GI / metab -ve low drug load local irritation |
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Classification route type
ocular route |
local
-ve wash out most drug small dose poor absorb |
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Classification route type
otic |
drops
local -ve low dose shit absorb |
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Classification route type
overall idea |
no single route is good for all
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absorption
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drug goes into blood w/o alteration
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factor affect aborption
anatomical |
surface area
thickness membrane pH gastric emptying time blood flow food |
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factor affect aborption
drug related |
dosage form type
dosage form design (delayed/sustained release) manufacturing factors (hardness, size..) excipients |
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Noyes-Whitney equation
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related absorption to factors of dissolution
dC/dt= D . A . (Cs-Cg) / h dc\dt= dissolution rate dc = amount of dissolved drug D= diffusion coefficient of drug in body fluids A = surface area of drug particles h = thickness of the diffusion “stagnant ” layer of solvent around the drug particle Cs= saturation solubility of the drug in the diffusion layer “h” Cg= concentration of the drug in the bulk solution of the gut |
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surface area
lipo hydro |
L-smaller the particle the smaller the S.A.
H- larger the particle the larger the S.A. |
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Saturation solubility of the drug (Cs):
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can be modified by pH
turning ionized and unionized amorphous, more soluble but less stable polymorphous opposite can be affected by complexation |
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Concentration of dissolved drug in the bulk solution (Cg) :
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if little crap in GI, drug distributes and reduces conc gradient and dissolution decreases
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Thickness of the diffusion layer (h):
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h decreases with increasing GI motility and increases with increasing the drug particles.
•drug particles dissolve, they reduce in size, cause h to decrease, increases the dissolution |
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Diffusion coefficient (D):
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•D dependsmainly on the radiusof the drug particle and the viscosityof the GIT fluids
•Increasingviscositywill decrease drug dissolutionand will slowgastric emptying, therefore delay absorption |
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Parenterals
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Parenterals“injectables” are sterileand pyrogen-free preparations injected through skin into internal body compartments
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Recently, there is a growth in the use of Parenterals, why?
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•New and better administration techniques
•Increase in the number of drugs that can be administered only by the parenteral route •Simultaneous administration of the multiple drugs in hospitalized patients •Extension of parenteral therapy to home •New forms of nutritional therapy |
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What is the role of a hospital pharmacist?
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–Clinical use
–IV admixtures –Stability –Incompatibilities –Unit-dosing packaging –Handling |
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Intravenous (I.V.):
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Injected into a vein using needles (venipuncture) or indwelling catheters
-bevel up, blood backflow –infusion rate range from 42-150 mL/hour, or at a lower rate to keep catheter open. risks-thrombus, embilism –Only clear, aqueous, non-precipitating, isotonic, and emulsionscan be injected. |
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Patient Controlled Analgesia (PCA) Device
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-automated I.V. delivery system
-constant and uniform analgesia -used for I.V., S.C., and epidural administration |
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Intramuscular (I.M.):
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Injected into a skeletal muscle.
5ml butt 2ml arm no blood enter -–Aqueous or oleaginous“oily” solutions, and suspensionscan be injected. risk- if miss cause neuro damage |
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Subcutaneous (S.C., S.Q., Sub-Q, hypodermic):
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between the skin and the muscle tissue
injected, up to 1.3-2 mL, no blood –Absorption and eliminationare slower than I.M. |
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Intradermal(I.D.):
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Injections into the skin“dermis” of the anterior surface of the forearm
–Vey small volume (0.1 ml) diagnostic purposes( |
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Parenteral Dosage Forms
•Solutions |
–Most injectable products are solutions.
–The vehicle can be aqueous or nonaqueous. |
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Parenteral Dosage Forms
•Suspensions |
The most difficult dosage form to formulate.
–Requires delicate balance of several physical and rheological factors |
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Official “USP” Types of Injections
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•[DRUG] Injection
•[DRUG] for injection •[DRUG] Injectable Emulsion •[DRUG] Injectable Suspension •[DRUG]for Injectable Suspension |
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Aq Vehicles for Injection
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-Sterile Water for Injection, USP
–BacteriostaticWater for Injection, USP:(not for newborns) –Sodium Chloride Injection, USP –Dextrose Injection, USP –Bacteriostatic Sodium Chloride Injection, USP (not for newborn) –Ringer’s Injection, USP –Lactated Ringer’s Injection, USP |
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Non Aqueous vehicles for Injection
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when the drug substance has limited water solubility or stability
-Fixed vegetable oils –Miscible solvents (cosolvents): glycerin, polyethylene glycol (PEG), propylene glycol (PG), alcohol |
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Added Substances in Parenteral Formulations
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Antimicrobial preservatives
Buffers Antioxidants Solubilizers Tonicity modifiers Chelating Agents Protectants |
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Overages
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excess amount withdrawn into syringe
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PyrogenTesting
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Rabbit’s Test, USP
Bacterial EndotoxinTest, USP |
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Particulate Mater Testing
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Sources of particulate matter:
•dust •Cloth fibers •Glass fragments •Materials leaching form the glass or plastic container or seal –Individual final products must inspected visually or automatically |
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Container/Closure Integrity Testing:
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–Vial and bottles are not subjected to this test
–For ampoules sealed by fusion immersing the ampoule in dye solution Apply negative pressure then release |
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Facilities Requirements
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Clean room (grade A air)
•“Aseptic Area”, the design must allow sanitization with disinfectants •Support area can be designed with less standards (clean room grade D) •Evaluation –Count the number of particles in the air –Microbiological sampling using agar culture plates |
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Why pharmacuetical liquids?
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easier to swallow
only suitable dosage form irritation flexibility immediate drug availability |
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disadvantages
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relative chemical stability
medium for microbial growth bulky more pronouced distaste potential dosing errors |
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Collodions
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-put on skin, wait solvent evap, impervious layer remain
-Collodion USP -Flexible Collodion USP -Salocyclic acid Collodion USP |
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Bacteriostatic examples and warning
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-not for youngins
-Thimerosal Phenylmercuric nitrate chlorobutanol phenol cresol methyl para hydroxy benzoate propyl para hydroxy benzoate benzyl alcohol benzalkonium chloride |
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Waters and process manu
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purified water- only ion exchange allowed
water for injection sterile water for inject-songle dose sterile water for irragation- single dose bacteriostatic water for injection sterile water for inhalation |
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Oils differ?
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Vegatable-fixed
Almond, Peanut, Sesame, Cottenseed, Soybean (Fatty acid ester and Liquid paraffin) Volitile- wintergreen, turpentine fixed- used I.M. produce depot action |
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Solvent vehicles for piq. preps
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alcohol
diluted alcohol glycerin propylene glycol isopropyl rubbing alcohol oils waters |
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solubility rules
organic vs inorganic |
organic-
basically stuff with lots of carbons and not charges big = organical inorganic charged ates ites ores thios mates ides shits most of those x-ep phosphates, carbonates, silicates, borate, hipochlorites |
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Relative terms solubility
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Very soluble
< 1 Freely soluble 1 to 30 Soluble 10 to 30 Sparingly soluble 30 to 100 Slightly soluble 100 – 1000 Very slightly soluble 1000 to 10000 Practically insoluble, or insoluble 10000 and over |
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Noyes Whitney equ
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loss of wieght per unit time = constant K * Surface area ( Conc. saturate - conc. instant)
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factor affect dissolution
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free surface energy and shape of particle
-temp -type agitation -amount of material already in -viscosity and volume solvent -conc of dissolved solute |
