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What are the advantages of Oral administration?
most common, simplest, easiest, most economical, high patient acceptance and adherence
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What are the disadvantages of Oral administration?
First pass effect, not suitable for the drugs poorly absorbed or significantly destroyed in the GI tract
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What are the advantages of parenteral administration?
reliability, precision of dosage, timed control of onset of action
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What are the disadvantages of Parenteral administration?
Discomfort, possibility of infection, tissue damage, need trained professional
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What are the advantages of mucosal administration?
Avoid the first-pass effect, relative ease and convenience
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What are the disadvantages of mucosal administration?
small area of absorption (nasal, oral), taste (oral), delivery limited by molecular weight of a drug, local tissue irritation, sensitivity to pathologic conditions
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What are the advantages of transdermal administration?
Easy to apply and remove, avoid first pass metabolism
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What are the disadvantages of transdermal administration?
Lag time to reach steady state (2-6 hours in some cases, not for rapid onset, limited by polarity and size of drug, may need permeation enhancement via chemical and/or physical means
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What are the advantages of Local administration?
Reduced systemic side effects, reduced dose requirement
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What are the disadvantages of local administration?
need to know the location that needs to be treated
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What are the potential advantages of targeted administration?
Reduce side effects of drugs on healthy tissues and enhance drug uptake by targeted cells
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What are medical motivations to studying drug delivery systems?
Increase efficacy and enable activities, decrease toxicity, Increase patient compliance and convenience, enabling tools
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What are the economic motivations to studying drug delivery systems?
Increase patent life and market share with unique drug delivery systems, increase patient and physician acceptance, Avoid costs of developing a new chemical entity
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What three areas do tablets transport?
Stomach, Small Intestine, Large Intestine
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What is the pH of the small bowel?
7
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What is the pH of the large bowel?
5
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What is the pH of the stomach?
1
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How long does a tablet stay in the stomach?
30 min
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How long does a tablet stay in the jejenum?
1.25 hours
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How long does a tablet stay in the Ileum?
1.5 hours
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How long does a tablet stay in the Ileo-caecal junction?
1.25 hours
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How long does a tablet stay in the colon?
20 hours
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What is the surface area of the duodenum?
2m2
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What is the surface area of the jejenum?
180m2
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What is the surface area of the ileum?
280m2
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what is the surface area of the colon?
1.5m2
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What is enteric coating?
a surface on the tablet that won't dissolve in the stomach but will allow the tablet to dissolve once it reaches the small intestine
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What are the five factors that affect absorption of drugs from tablets?
Permeability, dissolution, formulation, efflux, metabolism
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Does amorphous or crystalline dissolve better?
amorphous
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What is a crystalline solid?
it is the highly ordered structure of molecules which diffracts x-rays
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What is a polymorph?
differenct arrangements of crystal
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What is a crystalline solvate?
solvent is incorporated in the crystal lattice
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What is amorphous?
non crystalline solvent that possesses no long-range order and does not diffract x-rays
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What are the steps in development of the optimum solid form?
new drug substance--> characterize raw material--> determine crystal structure--> salt selection study --> assess polymorphism --> assess physical and chemical stability of desired form --> scale up
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What are the length of sides of a unit cell?
a,b,c
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What are the angles of the corners of a unit cell?
alpha, beta, gamma
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what is the cost of the ritonavir problem?
$900,000,000
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What are the steps in controlling the solid form?
select a solvent and add to the drug, prepare solution, filter, supersaturated solution, add seeds of the desired form, nucleation and crystallization, retrieve sample, characterize crystalline form
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Do amorphous or crystalline solids diffract xrays?
crystalline
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What are the four aspects of a formulation?
analytical, physical, pharmaceutical, physicochemical
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what factors are used to select the best salt?
aqueous solubility >1, no hydroscopicity
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What are the types of tablets?
simple uncoated, effervescent, buccal and sublingual, fast disintigrating, multilayered tablets, sugar coated
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granulation leads to (larger/smaller) particles and (increases/decreases) flow
larger;improves
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more binder = (smaller/larger) particles
larger
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what was the KV problem?
oversize tablets
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What are advantages of capsules?
easier to formulate, versatility in dosage form design
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What are disadvantages of capsules?
must still measure accurate, not as easy to make, more costly, more likely to be lodged in the esophagus
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What are the best ways to prevent esophageal adhesion?
take medications with water, continuous flow of saliva, remain standing for 30 seconds
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What are the steps in capsule filling?
empty capsules are oriented so that they all point the same direction, separation of caps from bodies, dosing of fill material, replacement of caps, ejection of filled capsule
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What dose is given to humans in the first human testing?
the No Observed Adverse Event Level seen in animals
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how many patients are tested and how many have a placebo?
6 patients are given the drug and 2 are given a placebo
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What must be specified before a drug is given to humans?
impurities, dissolution, moisture, assay
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What are advantages of soft gelatin capsules?
- oThe drug can be a liquid or at least dissolved, solubilized, or suspended in a liquid vehicle.
- oThe liquid fill is metered into individual capsuled thus a high degree of precision is achieved
- oA higher degree of homogeneity is possible
- oA content uniformity of �3% has been reported for soft gelatin capsules
- oBecause the drug is dissolved it is rapidly released
- oRapid release of capsule contents
- oGood bioavailability
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What are disadvantages of soft gelatin capsules?
- oDrugs can migrate to the shell
- oDrugs can degrade in the liquid state
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What formulations can be in soft gelatin capsules?
liquid or suspensions
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