L4 - Roles Of Dosage Forms And Excipients

Question 1

Why are drugs not administered as pure substances? (2)

Answer 1

• human errors
• difficult to accurately weigh every time

= need to formulate the dosage form

Question 2

What are dosage forms?

Answer 2

The means by which drug molecules are delivered to sites of action within the body

Question 3

What do we need in a dosage form? (8)

Answer 3

• accurate dosing
• protection and shelf-life
• protection from gastric juice
• mask test and odour
• placement of drugs directly within body tissues
• sustained/controlled release medication
• insertion of drugs into body cavities
• use of desired vehicle for insoluble drugs

Question 4

What is an excipient? And what should it be?

Answer 4

• All the other components of a formulation other than the API
• should be chemically and physiologically inert

Question 5

What are some uses for excipients? (5)

Answer 5

• help processing of the system during manufacture and accurate dose control
• control rate of absorption
• protect, support or enhance stability, bioavailability/acceptability
• assist in product identification
• enhance overall safety and effectiveness of the drug during storage and use

Question 6

What are differences in in-vivo absorption due to?

Answer 6

The excipients used in the formulation

Question 7

Why formulate to control dose? (2)

Answer 7

• Patient unlikely to be able to measure this amount
• difficult to manufacture - blend uniformity

Question 8

When can you not make a tablet (regarding dose)?

Answer 8

When the drug has poor flow/compressability

Question 9

Why are some tablets film coated?

Answer 9

Avoids gastric mucosal irritation
= peptic and mucosal ulers
= dyspepsia
= severe gastric pain and bleeding

Question 10

What are the types of dosage forms? (2)

Answer 10

• route of administration
• physical form

Question 11

What are some routes of administration? (9)

Answer 11

• oral
• topical
• transdermal
• rectal
• parenteral
• vaginal
• inhaled
• ophthalmic
• otic

Question 12

What are some physical forms?

Answer 12

• solid
• semisolid
• liquid

Question 13

What is a tablet?

Answer 13

Hard, compressed medication in round, oval or square shape

Question 14

What do excipient include in tablets? (3)

Answer 14

• dilutants, binders, glidants and dry lubricants: ensure compressibility, flow and efficient tabletting
• disintegrants: ensure tablet breaks up in the GI track
• sweeteners/ film coating: taste masking

Question 15

What are some requirements for an ideal oral solid dosage form? (6)

Answer 15

• remain stable
• bioavailable (releases drug in GIT)
• uniform drug content
• robust and resistant to disintegration during handling
• easy, cost effective to mass produce
• pleasent to take

Question 16

What is a buccal/sublingual tablet? + features (3)

Answer 16

Meds administered by placing them in the mouth (tongue or between gum and cheek)

• dissolve rapidly
• absorbed through the mucous membrane into blood strea,
• (bypasses the stomach and liver)

Question 17

What are effervescent tablets? + features (4)

Answer 17

Contain acid substances, react rapidly in the presene of water to effervesce
= dissolve or disperse in water

• rapid dispersion and dissolution
• pleasent tasting
• lubricant needs to be water soluble to release drugs
• tablet packaging is critical for stability

Question 18

What are capsules? And what are the 2 main types?

Answer 18

Formulation contained in gelating or hydrozypropyl methilcellulose matrix

• hard-shelled: dry powdered ingredients
• soft-shelled: oils and active ingredients dissolved or suspended in oils

Question 19

What are oral granules? (2)

Answer 19

• solid, dry aggregates of powder
• placed on the tongue and swallowed with water or dissolved in

Question 20

What are fast dissolving oral delivery formulations? + features (3)

Answer 20

solid dosage form that dissolves or disintegrates rapidly in oral cavity

• tablet disperses in saliva
  -absorbed from the mouth, pharynx and oesophagus
• either porous or soft moulded matrices or tablets
• peel-off blister

Question 21

What are types of liquid preparations? (7)

Answer 21

• solutions
• emulsions
• suspensions
• syrups
• elixir
• linctus
• oral drops

Question 22

What are solutions?

Answer 22

Clear liquid preparations for oral use

Solvents: alcohol, glycerin or propylene glycol and purified water

Question 23

What are emulsions?

Answer 23

Stabalised oil-in-water dispersions

Question 24

What are suspensions?

Answer 24

Liquid preparations for oral use that contain one or more APIs suspensed in suitable vehicles
- purified water with cellulose derivative polymers and thickening agents

Question 25

What are syrups?

Answer 25

Conc. aq, solution of sugar - masks taste

Question 26

What are elixirs?

Answer 26

Pleasently flavoured clear liquid - high proportion of ethanol in purified water and sucrose + antimicrobial preservatives = confers the stability of the prep

Question 27

What are linctuses? (2)

Answer 27

Viscous, liquid oral preparations: described for the relief of cough - high proportions of syrup and glycerol = demulcent effect - dose is typically small

Question 28

What are oral drops?

Answer 28

Liquid preparations for oral use to be administered in small volumes - can be solutions, suspensions or emulsions

Question 29

What are topical dosage forms? (3)

Answer 29

- ointments - creams - gels

Question 30

What are ointments? (2)

Answer 30

Viscous, semi-solid, greasy preparations - base usually anhydrous and immiscible with skin secretions - used as emollients/apply suspended or dissolved medicaments to the skin

Question 31

What are creams? And the 2 types?

Answer 31

Semi-solid emulsions, mixture of oil and water - oi-in-water (O/W) - water-in-oil (W/O)

Question 32

What are O/W creams features? (2)

Answer 32

- more comfortable - less greasy and more easily washed off

Question 33

What are W/O benefits? (2,2)

Answer 33

- more difficult to handle - many drugs which are incorporated into creams are hydrophobic - will be released more readily from W/O - more moisturising: provide an oily barrier, reduces water loss from the stratum corneum

Question 34

What are gels? And what are they used for?

Answer 34

- Semi-solid system in which a liquid phase is constrained within a 3D polymeric matrix having a high degree of physical or chemical cross-linking - medication, lubrication and some misc application like carrier for spermicidal agents to be used intra vaginally

Question 35

What are transdermal patches?

Answer 35

Medicated adhesives that are placed to deliver a specific dose of medication through the skin into the bloodstream

Question 36

What are the advantages of transdermal patches?

Answer 36

Provides a controlled release of the medicament

Question 37

What are suppositories/pessaries? What are they made by?

Answer 37

Suppositories: solid dosage forms for administration via rectum, vagina or urethra that melts, softens or dissolves - dissolving or dispersing the active ingredient in a base, poured into a mould and solidifies

Question 38

What are parenteral dosage forms?

Answer 38

Injections - an infusion method of putting liquid into the body

Question 39

What are the different forms of injections?

Answer 39

- Intravenous (IV) - Intramuscular - Subcutaneous

Question 40

What are IV injections? + advantages (2)

Answer 40

Liquid admistired directly into the bloodstream - rapid onset - 100% of drug is bioavailable

Question 41

What are Intramuscular injections? (2)

Answer 41

Injections of a substance directly into a muscle - may either be absorbed fairly quickly or more gradually - deltoid muscle, vastus laterails, gluteal muscles

Question 42

What are subcutaneous injections? + advantages

Answer 42

Injections given by injecting a fluid into the subcutis (layer of fatty tissue directly below the dermis - highly effective in administering vaccines

Question 43

What are inhaled dosage forms?

Answer 43

Any drug or solution of drug administered by the nal or oral respiratory tract - prepared as solutions, suspensions or a dry powder

Question 44

What are the different types of DDDs for inhalers? (3)

Answer 44

- pressuries metered dose inhaler (pMDI) = standard inhalers, spacers - dry powder inhaler (DPI) = active inhaler, passive inhalers - liquid dose inhaler (LDI) Nebuliser = pneumatic, ultrasonic

Question 45

What are opthalmic dosage forms? (2)

Answer 45

Saline containing drops used for medication in the eye - steoid, antihistamines, topical anesthetics - sometimes lubricating, tear replacing

Question 46

What are ophthalmic ointments?

Answer 46

Sterile semi-solid preparations for application to the conjuctive or eyelid margin

Question 47

What are otic dosage forms?

Answer 47

Ear drops - solutions, suspensions or emulsion instilled into the ear with a dropper - used to treat/prevent ear infections