1st Exam Flashcards
Extent of solubility of a substance in a specific solvent is measured as
Saturation concentration
Results when the simultaneous and opposing processes of dissolution and phase joining proceed at a constant rate
Equilibrium solubility
Standard technique to determine thermodynamic aqueous compound solubilty
Shake Flask Method
Factors affecting solubility
NHSSSPP
Examples of particle size reduction
Micronization and sprayd drying
Rely upon mechanical stress to disaagregate active compound
Particle Size Reduction
Physical means to improve solubility
PDMC
Chemical ways to improve solubiltiy
pBDCS
Refers to a group of solid products consisting of at least two different components, a hydrophilic matrix and hydrophobic drug
Solid Dispersion
Used to prepare fast release solid dispersion dosage forms
Hot-Melt Method
Advantage is the use of a lower temperature
Solvent Evaporatiog method
Same as fusion method but with intense mixing of the components
Hot-Melt Extrusion
Biphasic system consisting of nano sized drug particles stabilized by surfactants for either topical and oral use or parenteral and pulmonary administration
Nanosuspension
Applied to poorly soluble drugs that are insoluble in water and oi
Nanosuspension
Types of nanosuspension
PMHC
Suspension is prepared using high-sheer media filling
Media filling
Suspension of a drug and surfactant is forced under pressure through a nanosized aparture valve of a high pressure homogenizer
High Pressure Homogenizer
Technique in which precipitated particle suspension is homogenized which preserves the particle size
Combined precipitation and homogenization
Ibuprofen is BCS class?
2
Characteristics of a well designed drug product
- Precise dose in each dosage form
- Working according to a prescribed regimen
- Physically stable and appealing
- Clearly labeled with storage conditions and expiration date
Do not possess dissociable ions, freely soluble in in water
Non electrolyte
Composed of metal ions and electronegative elements
Inorganic acids bases and salts
Majority of the pharmaceutical and medicinal agents
Organic acids and bases
Best describe acid-base behavior
pKa and pH
For systemic infections, weak acid, pKa of 6.3, crystallize in low pH –> kidney damage
Sulfadiazine
Weak acid, pKa of 5.0. For UTI
Sulfisoxazole
Acidic, COOH group attached to the bicyclic ring called cephem
Cephalosporin
Instability of B lactam is the reason why it is poorly absorbed from the GI tract, IM for systemic infections
Cefoxitin
Contains and amino group at the cephalosporin side chain, resistant to acid, for UTI
Cefalexin
Tropine ester of racemic tropic acid, weak base because tertiary amine group
Atropine
Display both basic and acidic characteristics
Amphoteric Drugs
if pKa > pKb of basic group, ampholytes are…..
Ordinary ampholytes
pKa
Zwitterionic
Capable of donating more tha proton
Polybasic Acids
Capable of accepting two or more protons
Polyacidic bases
Mixtures of weak acid and its salt or weak base and its conjugate acid
Buffer
Effectiveness of a buffer in minimizing pH change
Buffer capacity
Process molecules undergo when they are transferred from the solid to the dissolved state
Dissolution
Reflects the effect of solubility and particle size of the drug raw material
Dissolution
Reflects the effect of formulation and manufacturing process variables
Disintegration
For non oral dosage forms
Drug release
Routinely used for QC and R and D
Dissolution
Noyes whitney
Dm/dt=DA(Cs -C)/h
Compendial buffers
pH = 1.2-6.8
Factors influencing in vitro
PPC
Factors influencing invivo
VpCHT
Volume of fasted stomach
20-50mL
Capacity of human stomach
1-1.6 L
Fasted small intestine volume
120-350 mL
Fed state of small intestine
1.6 L
Fluid flow volume in the intestines
9L
pH of gastric juice of fed stomach
Up to 5
pH of gastric juice of fasted stomach
1.5-2.9
pH of fasted small intestine
6-7.1
pH of fed small intestine
5.5-6.5
Steps in dissolution test
AMDSFSC
Preparation of medium
Method of Deaeration
Heat 41 degC
Sonicate
Filter using 0.45 um or less
Name all apparatus with number
1- rotating basket 2- paddle assembly 3- reciprocating cylinder 4- flow through cell 5-paddle over disk 6- rotating cylinder 7- reciprocating holder
First line apparatus in product development of controlled release preparationg
Reciprocating cylinder
For testing of products of poorly soluble drugs and chewable tablets, prevent cone formation
Reciprocating cylinder
For IR tablets and sugar coated tablets; suppositories, soft gelatin capsules semisolids powders granules and implants
Flow-through Cell
Specifically useful for transdermal patch
Rotating cylinder
Proposed apparatus 8
Franz diffusion cell/vertical diffusion cell
Property of a solid, liquid or gaseous solute to dissolve in a solid, liquid or gaseous solvent to form a homogenous solution
Solubility
