Pharmaceutics Exam II

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What is the difference between a drug and the dosage form?: A drug is the active ingredient (API - Active pharmaceutical Ingredient).
The Dosage Form is the form that the drug is taken in. (i.e. tablets, capsules, syrups...)
What is pre-formulation?: Studies done before processing the drug into the dosage form. i.e. Drug-excipient compatabilites
What information do we need to know in order to formulate a drug?: 1.Physical characteristics of drug.
2. Intended route of drug administration
3. Drug Stability
4. Drug-excipient Compatability
What steps are involved in pre-clinical work?: 1. Discovery of a new chemical entity (NCE)
2. Pre-formulation studies
3.Formulation studies
4. Animal testing
What steps are involved with clinical work?: 1. Phase I, II, III(human trial)
2. If phase III is successful, drug comes to market.
3. Phase IV, drug can be recalled.
Physical description involves what?: Solid (i.e. Is the powder crystalline/amorphous?)
Liquid (i.e. Is the liquid volatile?)
Gas
What does microscopic examination tell us about the substance?: 1. Particle Size
2. Particle Size distribution
3. Particle Shape
4. Crystal/Amorphous Structure
What is polymorphism?: A drug can exist in multiple forms
What factors could be impacted by polymorphic structures?: 1. Strenght of material
2. Particle Size
3. Solubility
4. Dissolution
5. Stability
What are solids that don't melt, but show a differnt transition?: Amorphous solids
Crystal A has a melting point of 120C while crystal B has a melting point of 270C. Which crystal is more stable?: Crystal B is more stable because it requires more energy to break the bonds.
The total number of particles that go into solution after an infinite period of time. Temperature is a factor.: Solubility
What are the factors that affect solubility?: 1. Temperature
2. pH of solution
3. Crystal Structure
4. Particle Size
What is the process by which a drug dissolves?: Dissolution
How is the partition coefficient determined?: K = conc. of drug in octanol/conc. of drug in water
What is the Noyes-Whitney equation used to find?: Diffusion and Permeability
Ionized ---> more soluble Unionized ---> more permeable: True
What is the concentration of H2O?: 55.3 moles/L
What is neutral pH at 37C?: 6.8
What two steps are important in the targeting of drug molecules?: 1. Penetrate the SOA in adequate concentration.
2. Avoid distribution in unwanted ares.
What concentrations does the therapeutic window exist between?: Minimum Toxic Concentration and Minimum Effective Concentration
What is the science of flow?: Rheology
Considering Newtonian Flow, what can be predicted if viscosity is given?: The rate of flow can be predicted.
1. Exhibits solid-like behavior initially. 2. The point at which it breaks down = yield value. 3. Once it flows, it is Newtonian behavior.: Features of a Non-Newtownian material
What are the three types of Non-Newtonian materials?: 1. Simple Plastic
2. Pseudo Plastic
3. Dilatant
What material is characterized by shear-thinning systems?: Pseudoplastic Flow
What material is characterized by shear thickening flow?: Dilatant Flow
What kind of material could be considered a subset of simple plastic and pseudoplastic?: Thixotropic material
(Shear thinning behavior induced upon stress)
What type of viscometer is used to measure the viscosity of Non-Newtonian materials?: Cone and Plate viscometer
What type of viscometer is used to measure the viscosity of thin liquids?: Ostwald Viscometer
What are semi-solid dosage forms intended for topical application?: ointments, creams, and gels
What is an emulsion?: It is a liquid suspended in a liquid. They key is to have two immiscible liquids.
Contain hydrocarbons, oils, waxes, or petrolatum: Oily Base (Oleaginous base)
Absorption bases - capable of aqueous base absorption. Needs surfactant: Water in oil emulsion
Water removable bases. Hydrophilic ointment used. (USP): Oil in water emulsion
Greaseless bases. Polyethylene glycols: Aqueous Bases
True or False? If you are looking for a local effect, absorption is desireable.: False
1. Want uniform product 2. Non-gritty product 3. Flow properties 4. Stability of the formulation: Objectives for preparing ointments
What are the three layers of the epidermis?: 1. Stratum Corneum (main barrier)
2. Stratum Lucidum
3. Stratum Granulosum
Protein lysed by salicylic acid.: Keratinized cells of the stratum corneum
This layer of the epidermis is very hydroscopic. It absorbs 4-5 times its weight in moisture.: Stratum corneum
Considering an ointment in a tube, is thixotropy desired?: No, a simple plastic or pseudoplastic consistency would be desired.
Considering a cream or lotion, would thixotropy be desired?: Yes
What type of consistency do gels have?: They have simple plastic consistency.
Are preservatives usually added to water-containing ointment bases or to oleagenous bases?: Preservatives are added to water-containing bases. Usually oleagenous bases do not require preservatives.
What are the two preparation methods to make an ointment/cream/gel: 1. Incorporation Method
2. Fusion Method
What are the steps influencing percutaneous Absorption?: 1. Dissolution of drug in the vehicle. (crystaline or amorphous???)
2. Diffusion through the skin
3. Absorption inside the skin
Most commercial patches have an occlusion barrier. What is this used for?: The barrier traps moisture. When hydration increases, absorption increases.
What are some methods of permeation enhancers?: 1. Increase hydration (polypropylene glycol)
2. Decrease consistency of lipoprotein matrix
3. Increase driving force for the drug.
1. Sonication 2. Electric Current 3. Temperature: Ways to increase the driving force for the drug.
Why is dermal clearance important?: If clearance is low, then absorption is low.
If clearance is high, then absorption is high.
Why is it important to rotate the site of the dermal system?: 1. minimize irritation
2. Dermal clearance
Unit for Shearing Stress: F/A
Unit for rate of shear: dV/dr
ή: Viscosity
Shear thinning behavior induced upon stress. Stays for 10-20 minutes even after the stress is removed.: Thixotropic materials
1. Site of application is important (stratum corneum can't be too thick) 2. Rotate the site 3. surface free of sebum/sweat 4. no defilatory creams/keratolyics 5. No hair at site 6. Do not alter package in any way.: Considerations for transdermals
What are vaginal suppositories called?: Pessaries
What are urethral suppositorries called?: Bougies
Melt/soften/Dissolve at body Temperature?: Important features of suppositories
What are some local effects of rectal suppositories?: 1. Used mostly for to relieve constipation.
2. antihemorrhoidal
3. local anestetics/vasoconstrictors/astringents/analgesics/emollients/protectives
What is a system that coats a surface?: Emollient
What are vaginal inserts used for?: 1. Contraceptives
2. Antiseptics used in feminine hygiene
What are urethral suppositories used for?: 1. Antibacterial agents
2. Antiseptics in urethral examination
What are some examples for systemic uses of suppositories?: 1. Relief from nausea and vomitting
2. Analgesia
3. Relief from migraine
4. analgesic/antipyretic
1. Anorectal Physiology 2. Colonic Content 3. Circulation Route 4. pH/Buffering capacity: Factors affecting Systemic absorption of suppositories
Which has the larger surface area; Large intestine or rectum?: Large intestine has significantly larger surface area.
Where do the upper, middle, and lower hemorroidal veins surrounding the rectum transport the blood?: The upper veins carry blood to the portal system.
The lower and middle veins bypass the portal system.
Why would you use and enema before inserting a suppository?: The enema is used to evacuate the colon, and there is much greater absorption from a void colon.
1. non-toxic/non-irritating to mucous membranes 2. compatible with a variety of drugs 3. Melt or dissolve in body fluids 4. Stable upon storage: Characteristics of Suppository Bases
Type of oleaginous suppository base: Cocoa Butter (also called Theobroman oil)
Type of water soluble suppository base: Polyethylene Glycols (PEG)
What is the difference between the alpha and beta polymorphs of cocoa butter?: The alpha has a MP of 30C and the beta has a MP of 35C. The beta form is preferred.
How can we avoid preparing the alpha form during formulation?: Never exceed 50C during formulation.
PEG with a MW of 400: Liquid
PEG with a MW of 1000-1600: Semi-solid
PEG with a MW of 1600: Solid Powder
What are the three ways to prepate a suppository?: 1. molding
2. compression
3. Hand rolling/shaping
What are the steps for preparing a suppository by molding?: 1. Melt the base
2. Incorporate desired drug
3. Pour into prelubed molds
4. Allow the melt to cool/congeal
5. removal/packaging/labeling

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