Pharm Formulation and Delivery Systems Flashcards
Area of study concerned with the formulation, manufacturing, stability, and effectiveness of dosage forms
Pharmaceutics
- The study of the relationship between the physical, chemical, and biological properties of a drug substance, dosage form and drug action
- The study of the physicochemical factors of drug dosage forms that influence the rate and extent of systemic drug absorption
Biopharmaceutics
The aim is to adjust the delivery of the drug substance to the site of action to provide optimal therapeutic activity
Biopharmaceutics
Importance of drug delivery
- must be present at site of action for adequate time
- more than 50% of developed drugs fail because they can not be silvered to target
Two approaches to achieve efficient drug discovery
- via a suitable drug delivery system/dosage form
- via a drug modification
Components of Pharmaceutical Dosage Forms
- Drug substance (API)
- Pharmaceutical ingredients (non-medicinal)
Product: Drug Substance + Excipients
Name at least 5 Pharmaceutic Ingredients
Binders, disintegrates, diluents, fillers, lubricants, flavors, compression aids, colorants, preservatives, glidants, suspending/dispersing agents, sweeteners, film coatings, printing inks
Purpose of Dosage Forms
To provide:
Consistent accurate administration
Convenient administration
A palatable form for administration
Controlled-release of drug
To protect:
The substance from environmentally-induced degradation
Purpose of Pharmaceutic ingredients
Impose patient acceptability and product stability, optimize production processes, enable product identification
In typical tablet formula Latino, what is the % composition of the API?
The desired dose
There is also diluents/fillers, binders, disintegrates, surfactants, lubricants/gildants
Preformulation considerations
The physicochemical characteristics of the drug, target site for drug, intended therapeutic use, age of target population, compatibility
Biopharmaceutical Classification System
See/draw figure on Slide 19
- process by which a solid of only fair solubility enters solution
- time for drug substance to dissolve in fluid at absorption site
Dissolution rate
Dissolution Rate
dM/DT=DS/h (Cs-C)
dC/dt=DS/Vh (Cs-C)
A solid particle with surface area S 9cm20 dispersed in a solvent of volume V is surrounded by a stagnant layer of thickness h (cm)
Diffusion coefficient (cm2/sec)
M is the mass of solute dissolved in time t
Notes-Whitney equation
dM/DT=DS/h (Cs-C)
dC/dt=DS/Vh (Cs-C)
A solid
Dosage forms with drug released features based on time, course or location that are designed to accomplish therapeutic or convenience objectives not achieved with immediate-release forms
Modified Release
- Delayed release
- Extended (sustained) release
- Controlled release systems
Designed to release the drug at a time other than immediately after administration
Delayed release (enteric-coated)
Defined as those that allow a reduction in dosing frequency compared with a conventional dosage form
Extended (sustained) release
Look over slides 26-28
Include a component that can be engineered to regulate essential characteristic and have a duration longer than a day
Controlled release systems
Type A and B Gelatins
Type A:
Acid processing of pork skins
Plasiticity and Clarity
pI 7.0-9.0
Type B:
Alkali processing of bones and animal skins
Firmness but is hazy
pI: 4.8-5.0
Usually mixture of A and B is used
Physicochemical properties of gelatin
Bloom strength
-Empirical measure of gel strength
-measured in Blood telomeres
Viscosity
Why is gelatin ideal material?
Swells but is insoluble in cold water Has the ability to form a thermally reversible gel Has excellent film-forming properties Freely soluble in the stomach secretions As a protein, is digested to amino acids
Characteristics of Enteric-coated Tabs
- Form of delayed-release
- Designed to pass unchanged through stomach
- Tablet disintegration in intestine allowing drug dissolution and absorption
- Sow to have substantially higher absorption in intestine when stomach is by-passed
- Unstable in gastric pH
- irritating in gastric mucosa
Tablet Additives (list at least 6)
- Diluents (fillers, bulking agents)
- Binders or Adhesives
- Lubricants and Antiadherents
- Disintegrants
- Colorants
- Flavoring Agents and Sweeteners
- Wetting Agents
