SUPPOSITORIES Definition merits limitations formulations suppository bases compounding

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: n Local effects n Systemic effects n Mechanical effects n Bye pass first pass metabolism n Alternative route for unconscious, elderly patients etc n Unpleasant drugs n Avoids gastric irritation & GI instability n Prolonged drug release

Limitations: n Aesthetic objection n Leakage n Unpredictable absorption n Mucosal damage Formulation: n Drug n Base n 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 – 36 oc - 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