PSC 4215 - Exam 1 - Suppositories

Sub

Under

Ponere

To place

3 Regions of the body are suppositories intended for

Rectal, Vaginal, Urethral

Which suppository can have systemic effects? Why?

• Rectal

• Middle hemorrhoidal veins can absorb the drug

3 Hemorrhoidal veins

1. Superior

2. Middle

3. Inferior

Swollen, painful rectal veins; often a result of constipation

Hemorrhoids

Characteristic of an ideal suppository base

Oleaginous or water soluble base that can melt at 37C or 98.6F and not leak out

(Others: Firm enough to insert at room temperature, Stable during manufacture & storage, Chemically compatible with drug, Non irritating)

1. Rectal suppository have _____ bases

2. Vaginal/urethral have _____ bases

• Rectal → Oleaginous such as cocoa butter

  (residues passes w stool)

• Vaginal/urethral → Water soluble

Theobroma oil

Coca butter

Cocoa butter composition (Hint: POLLS)

POLLS

• Palmitin

• Olein

• Laurin

• Linolein

• Stearin

and other long chain fatty acid glycerides

How to extract theobroma oil

Dissolve it in ether or chloroform and extract using separation

3 Limitations of cocoa butter in suppositories

• Hydrophobic (unsuitable for vaginal/urethral)

• Polymorphic (forms multiple crystals)

• The melting point decreases after adding the drug

2 Examples of cocoa butter substitutes (synthetics)

Witepsol and Wecobee

(long chain fatty acids that are synthesized)

3 Types of water soluble bases used in suppositories

PEG, Glycerinated gelatin, Surfactant

T/F: Water-soluble bases, such as polyethylene glycol (PEG)-based suppositories, tend to soften more slowly compared to fatty or oleaginous bases (like cocoa butter). This results in a slower drug release

T

PEG 4000 (2)

• Water soluble suppository base

• Takes long to soften so slower release

3 Methods to prepare suppositories

1. Hand rolling

2. Compression

3. Fusion (Molding)

Compression method for suppository formation

Mixes cocoa butter or peg with heat sensitive or insoluble drugs

Fusion/molding method for suppository formation

Melts cocoa butter, PEG, or glycerinated gelatin with drugs that ARE NOT heat sensitive. Insoluble powders must be finely dispersed

Factors to consider when choosing suppository bases

SCAR

1. Solubility of drug in bases

2. Compatibility of drug in base

3. Application site (no cocoa butter for vaginal/urethra)

4. Rate of drug release/ absorption

Rank rectal, vaginal, and urethral suppositories from smallest to largest

Urethral (Smallest) < Rectal < Vaginal (Largest)

Compressed tablets, soft gelatin capsules, and urethral inserts may be used as suppositories but may cause

Irritation and inflammation

(not recommended unless theres a need)

What could cause a fail in treatment of a urethral insert or rectal insert

Urinating or defecating less than 1 hour after insertion (not enough time to release/will not be in therapeutic range)

2 Advantages of suppositories

1. Avoids oral/ parenteral route (ex: oral surgeries)

2. Localized site of action (ex: hemorrhoids, infection)

4 disadvantages of suppositories

1. Inconvenience (ex: melt, deep)

2. Unpredictable absorption (ex: did it dissolve/ reach circulation? covered by mucus/ feces?)

3. Mucosal irritation

4. High cost

How deep should a rectal suppository be inserted?

Past the anal sphincter

8 Common Medications in Suppositories

1. Analgesics

2. Local Anesthetics

3. Antipyretics

4. Antiemetics

5. Cathartics

6. Sedatives/Hypnotics

7. Antibiotics

8. Antifungals