Ch 11- Capsules

be able to define a capsule

solid dosage forms in which the drug is enclosed within either a hard or soft container shell; usually formed from gelatin however may also be made from starch

properties of a hard gelatin capsule

-gelatin main component

-contains dyes, antioxidants, preservatives, water (13-16%), plasticizers

-consists of body (larger halve, smaller diameter) and cap (smaller halve, larger diameter)

what are hard gelatin capsules filled with?

active drug

diluent (inactive ingredient added to increase the volume of the powder)

glidants (increase powder flow)

lubricants (reduce powder to metal adhesion/reduce friction)

disintegrants

stabilizers

advantages of hard gelatin capsules

non-toxic

readily soluble in biological fluids

good film-forming material

high concentrations workable at low temp (50C)

solution undergoes reversible change from sol to gel at just a few degrees above ambient

purpose of adding soluble diluents and insoluble diluents

soluble diluent like lactose is added to poorly soluble compound to make it more hydrophilic

readily soluble are best mixed with insoluble diluents because they help the powder mass to break up without interfering with their solubility in the medium

define a soft gelatin capsule

a liquid or semisolid matrix inside a one-piece outer gelatin shell

how do SGCs differ from hard gelatin capsules

SGCs have continuous gelatin shell with no visible seam

shell is composed of gelatin, water and plasticizers (which make it soft)

SGCs are filled with liquid instead of a solid

why are SGCs used

increased rate of absorption (limited disintegration because drug is already in liquid)

increased bioavailability

this all increases patient compliance and consumer preference

oils and low melting points (liquid near room temp)

safety for potent and cytotoxic drugs

dose uniformity (a single piece unlike hard shells so more distribution)

product stability (dried shell has low oxygen permeability so longer shelf life)

formulation of soft gels

gelatin

plasticizers (account for 20-30% of the vet gel formulation and is more than hard shell)

water (contains less than hard shell)

colourants