Suppositories and inserts

Question 1

Suppositories

Answer 1

are solid dosage forms intended for insertion into body orifices, i.e.,
rectum, where they melt, soften or dissolve and exert local or systemic effects

Question 2

Suppositories have various

Answer 2

shapes and weights; the shape and size must be such that it can easily be inserted into the intended orifice without causing undue distension, and once inserted, it must be retained for the appropriate period of time

Question 3

Rectal suppositories are inserted

Answer 3

with the fingers

Question 4

Inserts

Answer 4

are solid dosage forms that are inserted into a naturally occurring
(nonsurgical) body cavity other than the mouth or rectum, i.e., vagina and urethra

Question 5

Certain vaginal inserts (and tablets) may be inserted

Answer 5

high in the tract with the aid of an appliance

Question 6

Rectal suppositories characteristics

Answer 6

Usually about 32 mm (1.5 in.) long

• are cylindrical
• and have one or both ends tapered
• Some shaped like a bullet, torpedo or the little finger

Question 7

Depending on the density of the base and the medicaments in the suppository, their
weights may vary

Answer 7

Adult rectal suppositories weigh approximately 2 g when cocoa butter (theobroma oil) is
employed as the base
– Ones used for infants and children are about half the weight and size and assume a more
pencil-like shape ( 1g)

Question 8

Vaginal inserts

Answer 8

Also called vaginal suppositories and pessaries

- can be tablets

Question 9

Vaginal inserts characteristics

Answer 9

Usually globular, oviform or coned-shaped and weigh about 5 g when cocoa butter is the base

Question 10

Urethral inserts

Answer 10

Also called urethral suppositories and bougies

Question 11

Urethral inserts characteristics

Answer 11

Slender, pencil-shaped and intended for insertion into the male or female urethra
- For males, may be 3 to 6 mm in diameter and approximately 140 mm long, although
this may vary
• When cocoa butter is employed as the base, these weigh approximately 4 g
• For females, are about half the length and weight of the male verversions, being about 70 mm long and weighing about 2 g, when made of cocoa butter

Question 12

Urethral inserts are used for

Answer 12

the treatment of local infections and erectile dysfunction

Question 13

Local and systemic action of suppositories and insert

Answer 13

Once inserted, the suppository base melts, softens or dissolves, distributing its
medicaments to the tissues of the region

Question 14

Rectal suppositories intended for local action are most frequently used to

Answer 14

relieve constipation or the pain, irritation, itching and inflammation associated with
hemorrhoids or other anorectal conditions

Question 15

Vaginal inserts intended for local effects are employed mainly as

Answer 15

contraceptives, antiseptics in feminine hygiene, and as specific agents to combat an invading pathogen

Question 16

Mucous membranes of the rectum and vagina permit

Answer 16

absorption of many soluble
drugs
– Rectal used frequently, the vagina not as frequently for systemic absorption

Question 17

Why might it not be practical for oral administration of a drug

Answer 17

in some circumstances during nausea and vomiting or convulsions, in uncooperative patients and before surgery)

Question 18

The rate and extent of rectal drug absorption are

Answer 18

often lower than with oral

absorption, possibly an inherent factor owing to the relatively small surface area available for drug uptake

Question 19

Some advantages of rectal

administration

Answer 19

1. Drugs avoid, at least partially, the first-pass effect
2. Drugs destroyed or inactivated by the pH or enzymatic activity of the stomach or
   intestines need not be exposed to these destructive environments
3. Larger doses can be administered, compared to oral administration
4. Drugs irritating to the stomach may be given without causing such irritation
5. No taste limitations
6. Convenient for administration of drugs to patients who are unable or unwilling to
   swallow medication, i.e., infants
7. An effective route in the treatment of patients with vomiting
8. Achievement of a rapid drug effect systemically, as an alternate to injection

Question 20

Some disadvantages of rectal administration

Answer 20

1. Not preferred by patients
2. Rectal absorption can be erratic
3. Can be expelled after insertion
4. The absorbing surface area of the rectum is much smaller than that of the small intestine
5. The fluid content of the rectum is much less than that of the small intestine, which may affect dissolution
6. Local irritation – Long term medication with rectal ergotamine and acetylsalicylic acid, for example, may result in rectal ulceration, and irritation after a single
   administration of several drugs and formulations has been described

Question 21

Factors that affect rectal absorption of drug

Answer 21

1. Physiologic factors

2. Physicochemical factors of the drug and the base:

Question 22

Physiologic factors

Answer 22

1. Colonic content
2. Circulation route
3. Essentially neutral pH and lack of buffering capacity of the rectal fluid

Question 23

Physicochemical factors of the drug and the base:

Answer 23

1. Lipid-water solubility
2. Particle size
3. Nature of the base

Question 24

Colonic content –

Answer 24

Greater absorption when rectum is empty

Question 25

Circulation route

Answer 25

Drugs absorbed rectally bypass the portal circulation during their first pass
into general circulation, enabling drugs that are otherwise destroyed in the liver to exert systemic
effects

Question 26

Essentially neutral pH and lack of buffering capacity of the rectal fluid

Answer 26

The form in which a drug

is administered will not generally be chemically changed by the environment

Question 27

Lipid-water solubility

Answer 27

An important consideration in the selection of the suppository base and in
anticipating drug release; Example: Lipophilic drug distributed in a fatty base in low concentration has less tendency to escape to the surrounding aqueous environment than a
hydrophilic substance in that base

Question 28

Particle size

Answer 28

Particle size of drug affects dissolution; the smaller the particle, the more readily
the dissolution and the greater the chance for absorption

Question 29

Nature of the base

Answer 29

Must be capable of melting, softening or dissolving; ideal characteristics:
Non-toxic, non-irritating and compatible with the incorporated drug

Question 30

Suppository bases

Answer 30

Play an important role in the release of the medication they hold and, therefore, in the
availability of the drug

Question 31

Suppository bases Should remain

Answer 31

solid at room temperature but soften, melt or dissolve readily at body
temperature so that drug is fully available soon after insertion

Question 32

Suppository bases: Release of drug and onset of action depend on

Answer 32

n liquefaction of the base, dissolution of

drug and absorption

Question 33

Classification of suppository bases

Answer 33

1. Fatty (or oleaginous) bases
2. Water-soluble and water-miscible bases
3. Miscellaneous bases

Question 34

1. Fatty (or oleaginous) bases

Answer 34

Perhaps the most frequently employed suppository bases, principally because
cocoa butter is a member of this group of substances
-Melt quickly at body temperature

Question 35

Fatty (or oleaginous) bases example

Answer 35

1. Cocoa Butter, NF is the fat obtained from the roasted seeds of
   Theobroma cacao; it is intended to melt over a narrow temperature range (30 to 36 C)
2. Triglyceride mixtures; their advantage over cocoa butter is that they
   do not exhibit polymorphism

Question 36

Advantages of cocoa butter

Answer 36

Advantages: Generally, non-irritating to membrane tissues and an excellent emollient

Question 37

disadvantages of cocoa butter

Answer 37

➢ Disadvantages: May give poor and erratic release of some drugs and exhibits
polymorphism

Question 38

Polymorphism

Answer 38

Polymorphs usually exhibit different physicochemical properties, e.g., melting point, solubility
- If a wrong polymorph is chosen for formulation, the metastable polymorph (i.e., the
thermodynamically unstable form) can convert to more stable polymorph resulting in
changes in solubility and, ultimately, bioavailability

Question 39

Water-soluble and water-miscible bases

Question 40

Glycerinated gelatin

Answer 40

is slower to soften and mix with physiologic fluids than is

cocoa butter and therefore provides a slower release

Question 41

that glycerin is hygroscopic which means that

Answer 41

it must protect from atmospheric moisture and

may irritate tissues because of its dehydrating effect

Question 42

PEG suppositories

Answer 42

do not melt at body temperature but rather dissolve in
mucosal fluids; thus, it need not be formulated to melt at body temperature
• Permits a slow release of medication from base

Question 43

Miscellaneous bases

Answer 43

Mixtures of oleaginous and water-soluble or water-miscible materials

Question 44

Oil-soluble drug:Oily base

Answer 44

Slow release; poor escaping tendency

Question 45

Water soluble drug:Oily base

Answer 45

Rapid release

Question 46

Oil soluble drug:Water-miscible base

Answer 46

Moderate release

Question 47

Water soluble drug:Water-miscible base

Answer 47

Moderate release; based on diffusion; all water soluble

Question 48

Suppositories are prepared by:

Answer 48

1. Molding from a melt

2. Hand rolling and shaping

Question 49

Vaginal inserts that are tablets are prepared

Answer 49

by compression

Question 50

The method most frequently employed both on a small scale and an industrial scale
today is

Answer 50

molding

Question 51

Molding steps include:

Answer 51

1. Melting the base
2. Incorporating medicaments
3. Pouring the melt into molds
4. Allowing the melt to cool and harden
5. Removing the suppositories from the mold

Question 52

Which bases are suitable for preparation by molding

Answer 52

Cocoa butter, glycerinated gelatin, polyethylene glycol and most other bases

Question 53

Packaging and storage

Answer 53

Most commercial suppositories are individually wrapped in either foil or plastic
- Some suppositories are packaged in a continuous strip, separated by tearing along
perforations
• Commonly packaged in slide boxes or in plastic boxes
• Label includes the route to be used
• It is necessary to maintain them in a cool place

Question 54

All of the following are characteristics of cocoa butter suppositories,
except:
A. Solid at room temperature, but melt quickly at body temperature
B. Demonstrate good emollient properties
C. Immiscible with body fluids
D. Fat-soluble drugs are rapidly released from them

Answer 54

*D. Fat-soluble drugs are rapidly released from them

Question 55

Which of the following is not an advantage of the rectal route?
A. Useful for administering drugs that irritate the stomach
B. Effective for treating nausea and vomiting
C. Avoidance of systemic drug absorption
D. Partial avoidance of first-pass metabolism

Answer 55

*C. Avoidance of systemic drug absorption

Question 56

Typically, rectal suppositories intended for pediatric use weigh
approximately
A. 1 g
B. 2 g
C. 3 g
D. 4 g

Answer 56

*A. 1 g

Question 57

Does 0.1 g of Drug X (density factor = 2) displace more cocoa butter than 0.2 g of Drug Y (density factor = 5)?
A. Yes
B. No

Answer 57

A. yes

0. 1 g / 2 = 0.05 g displaced
1. 2 g / 5 = 0.04 g displaced