making a medicine

Question 1

what is a medicine

Answer 1

drug delivery system

Question 2

what is a drug

Answer 2

active pharmaceutical ingredient (API); therapeutic agent

Question 3

what is a formulation

Answer 3

recipe for making a medicine, including ingredients ingredients and processes

Question 4

what is an excipient

Answer 4

ingredient that is not the drug ( a preservative)

Question 5

what is a dosage form

Answer 5

physical form of the medicine (tablet or capsule)

Question 6

what is pharmaceutics

Answer 6

science of medicine design and manufacture

Question 7

what is preformulation

Answer 7

characterization of the drug

Question 8

what is the rational formulation design

Answer 8

delivering the drug to the right site and making it useful
right dose
right place
right time

Question 9

what is the aim of formulation

Answer 9

optimal drug delivery to the therapeutic target to maximize therapeutic efficiency and patient safety
* Drug properties, e.g. solubility, permeability, stability
* Route of administration, e.g. target specificity, local vs. systemic
* Use and patient need, e.g. infants, elderly, dexterity, consciousness

Question 10

how can formulation enhance a medication, how are these enhancements achieved

Answer 10

drug delivery and targeting
processability and manufacturability
usability and user acceptability
stability

these enhancements are achieved using excipients and medical devices

Question 11

what is lipinskis rule of five

Answer 11

molecular weight <500
log P <5
H-bonds donors <5
H-bonds acceptors <10
assumes absorption by passive diffusion

Question 12

what is the formula of log P

Answer 12

log P= log (concentration in octane/ concentration in water)

Question 13

why is log P important

Answer 13

it determines permeability across biological membranes (affects absorption and ultimately efficacy and safety)

affects formulation decisions
solvent choice
dosage form (emulsion, suspension or solution)

Question 14

what affects solubility

Answer 14

solvent properties (polarity, PH)
solute properties (solid form, pKa)
temperature
pressure

Question 15

why is solubility important

Answer 15

It affects drug dissolution and absorption
* It is a key factor that determines oral bioavailability (i.e. BCS)
* It underpins formulation decisions (e.g. excipient choice)
* Many drugs that are poorly water soluble may have increased solubility and
absorption in a fatty intestinal environment (e.g. after a meal)
* Understanding how solubility may change allows formulation stability to be
predicted, and measures to be implemented to modulate it

Question 16

what is the importance of reformulation

Answer 16

determines the physiochemical properties of the drug:
compatibility and stability
ease of formulation (solubility)
processability (flow properties)

shows best formulation strategy such as suitable dosage form and route of administration

Question 17

how to calculate molecular dissociation

Answer 17

look ay HA and PKA log calculations

Question 18

why is molecular dissociation important

Answer 18

It affects drug solubility and absorption
Ionised form more water soluble, but non-ionised form better absorbed. It may vary with body site, e.g. different parts of the GI tract.
* Needs to be accounted for in deciding route of delivery and formulation
* May be leveraged (e.g. in enteric-coated formulations).
It can affect formulation instability
Ionised drugs may form insoluble precipitates with incompatible counter ions.