Dosage Forms Exam 3 Flashcards
What are the advantages/disadvantages of Tablets and Capsules dosage forms?
-stable
-accurate dose
-easy to use (patient compliance)
-low cost
-taste masking/controlled release
DISADVANTAGES
-hard for infants/children
-not suitable for non-oral medications
What are the advantages/disadvantages of IV solution?
-fast
-avoids GI tract environment
-for patients that cant swallow
DISADVANTAGES
-expensive
-not convenient
-associated with pain
What are the advantages/disadvantages of transdermal patches?
-mostly for local treamtment
What are the advantages/disadvantages of Intranasal spray?
-mostly for local treatment
-can be used for systemic drug delivery
What is the difference between solid state versus solution?
Solution
-faster to act
-less stable
-more for parenteral administration (not by mouth)
Solid state
-slower to act
-more stable
-more convenient
-common for oral administration
What is preformulation?
-determining the physiochemical properties necessary to formulate the compound
What is formulation?
determining the route and composition of the final dosage form
What is manufacturing?
What unit operations are necessary for final dosage preparation
What are some roles/types of excipients?
-diluents
-disintegrants
-binders
-lubricants
-glidants
-controlled release (functional)
-preservative
-solubility enhancer
-stability enhancer
-taste masker
What do Diluents do?
-bulking agents
-needed to make practical weight for tablet and keep it together, enhances powder flow (for manufacturing)
ex. lactose, starch, compressible sugar
What do Disintegrants do?
-breaks up tablet, enhancing dissolution
-works by either water uptake and/or swelling
ex. sodium starch glycolate, starch, croscarmellose sodium
What do binders do?
-gives tablet mechanical strength, creates granules in wet milling
-water uptake/swelling
ex. Polyvinylpyrrolidone, Starch, Polymers, microcrystalline cellulose
What do lubricants do?
-prevents tablet from sticking to the press
-overlubrication can affect dissolution
ex. Magnesium stearate, stearic acid
What do glidants do?
-improves powder flow, stops inter-particle friction
-very fluffy
ex. Fumed Silica (collodial silicon dioxide), Talc (has issues with asbestos)
What do controlled release/Protection excipients do?
-extends the release of drug from a matrix
-coats a tablet for specified release
ex. HPMC, hypromellose, Xanthan gum
protection- Eudragits- poly(meth)acrylates
What do coloring agents do?
-improve esthetics, identification to use, control product, help in case of poisoning
-can be combined with sugars, starches
What is polymorphism?
-ability of a molecule to adopt two or more conformations/arrangements of molecules in the crystal lattice
what does modified-release mean?
-the time course, location of drug release or both are altered to accomplish therapeutic objectives not achieved by conventional dosage forms
What are the types of modified release?
Zero-order-releases drug at a constant and known rate
variable-release drug at variable rates so as to match circadian rhythms (useful when changes in blood concentration are necessary)
Bio-responsible- drug release triggered by a change in biological stimulus such as pH, temperature, or concentration of some disease marker (insulin)
-delayed-release delivery system
-Extended-release delivery system (sustained, controlled, prolonged, etc.)
What are diffusion systems?
-release rate of the drug is determined by diffusion through a poorly water-soluble polymer
-reservoir device: core of drug surrounded by a poorly water-soluble polymeric membrane
-Matrix device: dissolved or dispersed drug is distributed uniformly throughout a polymer matrix. diffusion through the matrix is rate-limiting step
What is Flux?
mass of drug that moves through a membrane per unit time. Fick’s law
-Zero-order release kinetics has a constant flux (reservoir system)
-Matrix device is not zero order and release rate is proportional to t-1/2
What is Fick’s law of diffusion?
-for steady state diffusion
What factors affect permeability?
-lipophilicity, solubility
-properties of membrane (hydration state, pH, penetration enhancers)
-dictated by diffusion
What is a syrup?
a drug solution containing sugar or a sugar subsititute
