oral solution

Question 1

definition of pharmaceutical solutions

Answer 1

liquid preparations in which therapeutic agent and excipients are dissolved in liquid solvent system

Question 2

aromatic waters

Answer 2

saturated aqueous solutions of volatile substances

Question 3

elixirs

Answer 3

oral solutions containing alcohol

Question 4

spirits

Answer 4

alcoholic or hydroalcoholic solutions of volatile substances, some are used as flavorings agents and some as medicines

Question 5

advantages of oral solutions

Answer 5

fast and onset drug action
dose uniformity is assured
volume of liquid dose can be measured accurately to tailored dose
easy to swallow
easy to manufacture

Question 6

disadvantages of oral solutions

Answer 6

less stable in solid dosage forms
colour change
precipitation
microbal growth

can be hard to dissolve in water
may have unpleasant taste or odour
packaging, transportation and storage costs are too high

Question 7

why does drug concentration need to be below saturation

Answer 7

to avoid precipitating

Question 8

why is water the most commonly used solvent

Answer 8

lack of toxicity
low cost
purified water is used as tap water could contain substances that interfere with drug formulation
purified water is produced by distillation, ion exchange or reverse osmosis

Question 9

what is purified water used for

Answer 9

used for the preparation of medicines that do not have to be sterile

Question 10

what is highly purified water used for

Answer 10

preperation of medicines where water of high biological quantity is needed, except water for injections

Question 11

what is water for injections used for

Answer 11

used for medicines for paternal administration
must be pyrogen-free

Question 12

what is steralized water for injections used for

Answer 12

medicines for paternal administration
water has been sterilised by heat and is suitably packaged

Question 13

what are nonaqueous solvents

Answer 13

Used when the drug is insufficiently soluble or stable in aqueous systems, or when a
solution is intended for specific properties, such as sustained drug absorption.

Question 14

viscosity enhancer (excipients)

Answer 14

improve pouring quality

Question 15

preservatives (excpients)

Answer 15

prevent microbial growth

Question 16

sweeteners (preservatives)

Answer 16

improve palatability of oral solutions

Question 17

antioxidants (excipients)

Answer 17

improve stability of the solutions by minimizing oxidation

Question 18

flavoring agents

Answer 18

mask unpleasant taste of drugs

Question 19

what factors can affect the stability of a solution during its shelf life

Answer 19

interactions with container closure system such as
high temperature
pH
oxygen
UV light
catalysts

Question 20

coloring agents

Answer 20

correlate with the flavouring agent

Question 21

methods to enhance solution stability

Answer 21

formulate at a suitable pH
include excipients to enhance product stability
include antioxidants or metal chelators to reduce oxidation
package in containers that reduce light transmission
add nitrogen to create nitrogen headspace

Question 22

what affects drug solubility and how can you increase solubility

Answer 22

molecular and crystal structure
solvent
pKa
PH of the medium

solubility can be increased by
pH modification
co-solvent
complexation
surfactant

Question 23

look at henderson hassle bach equation

Answer 23

okay

Question 24

how does altering pH increase drug solubility

Answer 24

altering pH can increase ionisation which increases drug solubility

Question 25

what is a co-solvent system

Answer 25

a system where a water-miscible or partially miscible organic solvent is mixed with water to form a modified solution. this is called solvency

Question 26

why are co solvents used

Answer 26

co solvents are used as many drugs are nit water soluble.
this allows them to dissolve such as ionic bonds since ‘like dissolves like’

Question 27

what are cyclodextrins

Answer 27

a family of compounds made up of sugar molecules bound together in a ring
the 3 most important cyclodextrins are:
6- membered sugar ring
7- membered sugar ring
8- membered sugar ring

Question 28

cyclodextrins complexation

Answer 28

they are in a hollow truncated cone shape
their effect is to increase aq solubility of drugs
when orally administered the drug is released and can absorbed by the body

Question 29

regions of a surfactant and its function

Answer 29

the two regions are hydrophobic and hydrophilic regions
reduces the surface tension of liquids
self assembled to form micelles at the critical micelle concentration

Question 30

considerations when switching between oral formulations of the same drug

Answer 30

administration times
bioavailability differences
excipients (allergy)
modified release formulation
site of action