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Pharmaceutics 2 > suppositories > Flashcards

suppositories Flashcards

1
Q

what are suppositories

A

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

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2
Q

Latin supponere meaning “to place under” Suppositories are commonly used rectally and vaginally, and occasionally urethrally

A

ok

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3
Q

how are different suppositories are inserted

A

Rectal suppositories are inserted with the fingers.
Certain vaginal suppositories (particularly the inserts or
tablets prepared by compression) may be inserted high
in the tract with the aid of an appliance.

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4
Q

what is the rectal suppositories physical appearance

A

Rectal suppositories are usually about 32 mm (1.5
inches) long, are cylindrical, and have one or both end
tapered ( bullet- or torpedo-shaped)

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5
Q

on what does the weight of the suppository depend on

A

density of the base and the medicinal agent in the
suppository.

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6
Q

adult suppositories—-2g when we use cocoa butter
infant and children—– half the weight and pencil shaped
vaginal suppositories—— globular, oviform and con shaped

A

ok

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7
Q

what are the local effects for rectal supps

A

– Relieve constipation.
– Relieve pain, itching and inflammation associated
with hemorrhoids.

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8
Q

what do antihemorrhoidal supps contain

A

– Local anesthetics
– Vasoconstrictors
– Astringents
– Analgesics
– Soothing emollients
– Protective agents

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9
Q

what do anticonstipation supps contains

A

glycerin suppositories that promote laxation by local
irritation of the mucous membranes (probably by the
dehydrating effect of glycerin on these membranes)

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10
Q

what do we use local vaginal supps for

A

-Contraceptives: nonoxynol-9
– Antiseptics
– Specific agents to combat invading pathogens
and treatment of vaginitis caused different
microorganisms.

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11
Q

do we use the vagina or rectum for systemic effects

A

rectum

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12
Q

what are the advantages for using rectal supps for systemic effects

A
  1. Drugs that are destroyed by the pH or enzymatic
    activity of the stomach or intestine need not to be
    exposed to these destructive environments.
  2. Drug irritating to the stomach may be given without
    causing such irritation.
  3. Drugs destroyed by portal circulation may bypass
    the liver after rectal absorption.
  4. This route is convenient for administration of drugs
    to patients who are unable to swallow medications.
  5. It is an effective route for treatment of patients with
    vomiting
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13
Q

examples for systemic supps

A

– Prochlorperazine and chlorpromazine: relief
of nausea and vomiting
– Oxymorphone HCl: opioid analgesic
– Ergotamine tartrate: relief of migraine.
– Indomethacin: NSAID analgesic and
antipyretic.
– Ondansetron: relief of nausea and vomiting.

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14
Q

what are the factors that controls absorpriton in rectal supps

A

– Physiological factors.
– Physicochemical factors of the drug and the
base.

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15
Q

The human rectum is approximately 15 to 20 cm long.
–
When empty of fecal material, the rectum contains only
2 to 3 ml of inert mucous fluid.
–
In the resting state, the rectum is not motile; there is no
villi or microvilli on the rectal mucosa.

A

ok

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16
Q

what are the physiological factors

A
  1. The colonic content
  2. The circulation route
  3. The pH and lack of buffering capacity of rectal
    fluids.
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17
Q

how does the colonic content effect absorption

A

Greater absorption (↑ systemic effects) may be
expected from a rectum that is void than from one
that is distended with fecal matter.
(make contact with the absorbing surface of the rectum and colon in an empty rectum.)

other factors
– Diarrhea
– Colonic obstruction due to tumorous growths
– Tissue dehydration.

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18
Q

how does the circulation route effect absorption

A

bypass the portal circulation during their first pass into the general
circulation  enabling drugs otherwise destroyed in the liver to exert systemic effects.

– The lower hemorrhoidal veins surrounding the
colon receive the absorbed drug and initiates its
circulation throughout the body, bypassing the liver.

– Lymphatic circulation also assists in the
absorption of rectally administered drugs.

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19
Q

how does the ph effect absorption

A

Rectal fluids are essentially neutral in pH (7.5 – 8),
and have no effective buffer capacity  the form in
which the drug is administered (salt or free form) will
not generally be chemically changed by the
environment.

20
Q

why do we use and for what do we use cocca butter

A

While cocoa butter melts rapidly at body temperature, Because of its
immiscibility with rectal fluids  it fails to release fat-soluble drugs readily. using a cocoa butter base, it is preferable to incorporate the ionized (salt) form rather than the unionized (free) form

For hydrophilic, water miscible bases such as,
glycerinated gelatin and polyethylene glycol, the free
form (unionized form) or the salt form can be used 
these bases themselves tend to dissolve slowly and
thus retard the release of the drug regardless of the
form. (

21
Q

why do we use and for what do we use cocca butter

A

While cocoa butter melts rapidly at body temperature, Because of its
immiscibility with rectal fluids  it fails to release fat-soluble drugs readily. using a cocoa butter base, it is preferable to incorporate the ionized (salt) form rather than the unionized (free) form

For hydrophilic, water miscible bases such as,
glycerinated gelatin and polyethylene glycol, the free
form (unionized form) or the salt form can be used 
these bases themselves tend to dissolve slowly and
thus retard the release of the drug regardless of the
form. (

22
Q

what are the physicochemical factors

A
  1. The relative solubility of the drug in lipid and in
    water:
  2. Particle size of the dispersed drug:
  3. Nature of the base:
23
Q

how does the particle size effect the absorption

A

 ↓in particle size  ↑ surface area, A
 ↑ surface area, A  ↑ increases dissolution
rate.
 ↑ increases dissolution rate  ↑ in rapid
absorption

24
Q

– As mentioned previously, water soluble bases (e.g.,
polyethylene glycol) that dissolves in the rectal fluids
releases for absorption both, water-soluble and lipidsoluble drugs.
– The more drug a base contain  the more drug will
be available for absorption.
until saturation

A

ok

25
Q

what are the properties of a good base

A
  1. The base should be solid at room
    temperature, but must be capable of melting,
    softening or dissolving at body temperature to
    release the drugs for absorption
  2. The base should not interact or complex with
    the drug  this will slow or even prevent drug
    release.

3.t should not irritate the mucous membrane of the
rectum  this will initiate a colonic response and
cause bowel movement. This will lead to
elimination of the drug product outside the body

26
Q

give an example for long acting supps

A

morphine sulfate in slow-release
suppositories. It can be compounded by the
pharmacist by including alginic acid in the base
which will prolong the release of morphine over
several hours.

27
Q

give examples on the advantages of diffirent bases

A

cocoa butter melts quickly at body temperature and would release
drugs very fast. Cocoa butter will give excellent release of water-soluble drugs. When irritation or inflammation is to be relieved
(such as in hemorrhoids), cocoa butter appears
to be the superior base because of its emollient
or soothing effects.

Fat soluble drugs seems to be more readily
released from bases such as glycerinated gelatin
and PEG.However, glycerinated gelatin and PEG bases
dissolves slowly in body fluids. The release
therefore is not as fast as for water-soluble drugs
from cocoa butter base

28
Q

give examples on the advantages of diffirent bases

A

cocoa butter melts quickly at body temperature and would release
drugs very fast. Cocoa butter will give excellent release of water-soluble drugs. When irritation or inflammation is to be relieved
(such as in hemorrhoids), cocoa butter appears
to be the superior base because of its emollient
or soothing effects.

Fat soluble drugs seems to be more readily
released from bases such as glycerinated gelatin
and PEG.However, glycerinated gelatin and PEG bases
dissolves slowly in body fluids. The release
therefore is not as fast as for water-soluble drugs
from cocoa butter base

29
Q

what are the diffrent classes for bases

A

A. Fatty or oleaginous bases
B. Water-soluble or water-miscible bases
C. Miscellaneous bases: usually a combination
of lipophilic and hydrophilic substances.

30
Q

give examples for fatty bases

A

cocca butter
– Hydrogenated fatty acids of vegetable oils such
as palm kernel oil and cottonseed oil.
– Compounds containing glycerin with highmolecular weight fatty acids(e.g., palmitic acid
and stearic acid): examples include glyceryl
monopalmitate and glyceryl monostearate

31
Q

talk about cocca butter

A

– Defined as the fat obtained from the roasted seed of
theobroma cacao.
– Appearance: at room temperature it is a yellowish white
solid having a faint, agreeable chocolate-like odor
– Chemical composition: it is a triglyceride primarily
of oleopalmitostearin and oleodistearin.

– Melting point: 30 to 36 C.

– Because of its melting point, it is an ideal base as
it melts just below the body temperature and yet
maintaining solidity at usual room temperatures.

– However, because of its triglyceride content, it
exhibits marked polymorphism (existence in
several crystalline forms).

should be melt at 23 in a warm water bath

Substances such as phenol and chloral hydrate have
a tendency to lower the melting point of cocoa butter.

– If the melting point is low enough (because of
additives) that it is not feasible to prepare a solid
suppository using cocoa butter alone as the base 
solidifying agents like cetyl esters wax (~20%) or
beeswax (~40%) may be melted with the cocoa butter
to compensate for the softening effect of the added
substance.
– However, the hardening agent:
• Must not be so excessive as to prevent the base
from melting in the body
• Must not interfere with the therapeutic agent in any
way or alter the efficacy of the product.

32
Q

give examples for water soluble bases

A

– Glycerinated gelatin
– Polyethylene glycol

33
Q

talk about Glycerinated gelatin

A

– Prepared by dissolving granular gelatin (20%/) in
glycerin and adding water or a solution or a
suspension of the medication (10%).

– Most frequently used in preparation of vaginal
suppositories  where prolonged action of the
medicinal agent is usually desired

– The reason of the prolonged action is that the
glycerinated gelatin base is slower to soften and mix
with the physiological fluids than is cocoa butter 
slower drug release.

– Glycerinated gelatin-based suppositories have a
tendency to absorb moisture as a result of the
hygroscopic nature of glycerin  they must be
protected from atmospheric moisture if they are to
maintain their shape and consistency.

– Also a result of hygroscopicity, the suppository has a
dehydrating effect and may irritate the tissue upon
insertion.

the water in the formula for the suppositories minimizes
this effect.

34
Q

talk about polyethylene glycol

A

– Polymers of ethylene oxide and water
– It is prepared at various:
–Chain lengths
–Molecular weights
–Physical states

– The are available in a number of molecular weight
ranges, the most commonly used are summarized
in the table 1.
– Note: the numeric designation refers to the
average molecular weight of each of the polymers.

– Various combination of these polyethylene glycols may
be combined by fusion

Polyethylene glycol suppositories do not melt at body
temperature but rather dissolve slowly in the body’s
fluids.
Therefore, the base need NOT to be formulated to melt
at body temperature.

35
Q

what are the advantages of PEG

A

• Permits slower release of the medication from
the base once the suppository is inserted.
• Permit convenient storage of these
suppositories without the need for refrigeration
and without danger of softening excessively in
warm weather.
• Permits slow insertion without fear that they
would melt in the fingertip (as cocoa butter
suppositories sometimes do).

36
Q

what are miscellaneous bases

A

• These are mixtures of oleaginous and water-soluble
or water-miscible materials.

• These mixtures may be chemical or physical
mixtures.

• Some of these materials are preformed emulsions
(generally w/o type) or they are capable of
dispersing in aqueous fluids and making emulsions.

• Example: polyoxyl 40 stearate.

37
Q

talk about Polyoxyl 40 stearate

A

it is a surface active agent that is employed in a
number of commercial suppositories.
– Compositions: it is a mixture of the following:
• Monostearates ester of mixed polyoxyethylene
diols.
• Distearates ester of mixed polyoxyethylene diols.
• Free glycols.
– The average polymer length is about 40
oxyethylene units.
– Appearance: it is white to light tan waxy solid
– It is water soluble.
– Melting point: 39 – 45 C.

38
Q

what are the methods of prepearing supps

A
  1. Molding from a melt.
  2. Compression
  3. Hand rolling and shaping
39
Q

how do we prepare by molding

A
  1. Melting the base.
  2. Incorporating any required medicaments.
  3. Pouring the melt into the mold.
  4. Allowing the melt to cool and congeal into
    suppositories.
  5. Removing the formed suppositories from the
    mold.
    •
    Most bases are suitable for preparation by molding
    such as, cocoa butter, glycerinated gelatin,
    polyethylene glycol.
40
Q

how do we prepare by molding

A
  1. Melting the base.
  2. Incorporating any required medicaments.
  3. Pouring the melt into the mold.
  4. Allowing the melt to cool and congeal into
    suppositories.
  5. Removing the formed suppositories from the
    mold.
    •
    Most bases are suitable for preparation by molding
    such as, cocoa butter, glycerinated gelatin,
    polyethylene glycol.
41
Q

what are the diffirent molds

A

– Commercially available molds can produce
individual or large numbers of suppositories of
various shapes and sizes.

– Plastic mold may be used to produce as little as a
single suppository.

– Metal molds that are commonly used for
pharmacy or laboratory scale production are
capable of producing 6, 12, or more suppositories
in a single operation.

– Industrial molds produce hundreds of
suppositories in a single batch.

42
Q

what are the trades of now days molds

A

– Molds in common use today are made of stainless
steel, aluminum, brass, or plastic.
– The molds usually separates into sections, generally
longitudinally.
– The molds are opened for cleaning before and after
preparation of a batch of suppositories.
– The molds are closed when the melt is poured and
opened again to remove the cold molded
suppositories.
– Care must be taken during cleaning the molds as any
scratches on the molding will take away from the
desired smoothness of the suppositories. It may
cause the suppository to stick on the mold and get
damaged while removing from the mold.

43
Q

why do we lubricate the molds

A

– Suppository molds may require lubrication before the
melt is poured to facilitate clean and easy removal of
the molded suppositories.
This will depend on the formulation
– When cocoa butter or polyethylene glycol are used as
base, lubrication is usually unnecessary  these
materials contract sufficiently on cooling to separate
from the inner surfaces of the mold and allow easy
removal.
– Lubrication is necessary when glycerinated gelatin is
used as the base.
– A thin coating of mineral oil applied with the finger to
the molding surfaces usually suffice.

44
Q

why do we and how do we calibrate molds

A

we calibrate them because the diffrence in density

  1. Prepare molded suppositories from base material
    alone.
  2. Remove the suppository from the mold.
  3. Weigh the suppositories: record the total weight
    and the average weight.
  4. The suppositories are then carefully melted in a
    calibrated beaker
  5. Determine the volume for the total number as
    well as the average of one suppository.
45
Q

remember df= weight of the drug\the weight of the base dispalced

A

ok

Pharmaceutics 2 (4 decks)

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