Suppositories

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Transcript Suppositories

SUPPOSITORIES
- Definition
-
merits
limitations
formulations
suppository bases
compounding
labeling
displacement value
evaluation
- solid or stiffened semi-solid dosage form for insertion
into body cavities other than mouth
1.
2.
3.
4.
5.
Types
Rectal
Vaginal (pessaries)
Urethral bougies
Ear (ear cones)
Nose bougies
Merits:
 Local effects
 Systemic effects
 Mechanical effects
 Bye pass first pass metabolism
 Alternative route for unconscious, elderly patients etc
 Unpleasant drugs
 Avoids gastric irritation & GI instability
 Prolonged drug release
Limitations:
 Aesthetic objection
 Leakage
 Unpredictable absorption
 Mucosal damage
Formulation:
 Drug
 Base
 Other additives – surfactants, soothing agents,
antioxidants, preservatives, anti-settling agents (blend of
higher m.p waxes & fatty acids )
Methods of preparation:
1.
Hand rolling method (trituration)
2.
Moulding method (fusion)
3.
Cold compresion method
Labeling:
- For rectal use only
- Store in a cool dry place or
- To be refrigerated etc
Ideal properties of a suppository base:
Easily melt and dissolve or disperse
Release medicament readily
Retain shape while handling
Non-toxic & non-irritant
Stable & compatible
Moldable, non adhering
Bases:
I. Oleaginous (fatty) bases
a) Natural - cocoa butter or their substitutes
b) Synthetic - witepsol, massuppol
II. Hydrophilic (water soluble/miscible) bases
a) Natural - glycero gelatin
b) Synthetic - macrogols
Cocoa butter:
- m.p 30 – 36oc
- Readily liquefiable on warming and rapid setting on
cooling
- Blandness
Limitations:
- Polymorphism – unstable gamma/beta forms
- Adhere to mould due to contractility on solidification
- Softening point too low for hot climates (beeswax may
be added)
- Batch to batch variation in composition
- Becomes rancid on storage
- Immiscible in body fluids and poor water absorption
- Tendency to leak, immiscibility makes it not suitable for
vaginal and urethral route
- May melt at warmer climates
Synthetic bases:
- readily available
- do not become rancid
- chemically more inert
- do not exhibit polymorphism
- good water absorption and emulsification properties
- lubrication can be avoided
- white, smooth & odorless
- may become brittle & fracture if cooled rapidly
Glycero-gelatin:
- may cause irritation due to dehydration of mucosa
- hygroscopic, careful storage
- incompatible with many drugs
- chance for microbial growth
- base preparation is time consuming
- sticky, can’t be used for hand rolling
Macrogols:
- combination for adjusting m.p, hardness etc
- may produce irritation due to hygroscopic nature
- suitable for tropical climates
- good solvent properties
- less liable to leakage due to high viscosity
- do not become rancid
- physiologically inert
- do not support microbial growth
- give clean & attractive suppositories
- form complex with some drugs & retard release
Displacement value:
- the number of parts by weight of drug that displaces
one part of base.
Calculation of DV:
1.
Wt. of 6 CB suppository, WCB
2.
Wt. of 6 medicated(40%) suppository, WMS
3.
Wt. of drug in suppository, WD = WMS x 40/100
4.
Wt. of CB in suppository, WB = WMS – WD
5.
Wt. of CB displaced by drug, WDCB = WCB – WB
6.
Displacement value, DV = WD /WDCB
Evaluation:
- appearance
- wt. variation
- content uniformity
- melting temp.
- drug release
- stability studies