Tablets

a-Coating material:

1-protect act. Ingradient against o2,moisture,temp(environmental conditions).

2-mask undesirable odour.

3-mask bitter taste of drug.

b-Enteric coating:

Tablet resist dirintegration,dissolution in stomach but in intestine due to

1-act.constituent decompose by acidic ph of stomach(1.2ph)

2-prevent irritation of certain drugs of stomach mucosa as nausia,vomiting and ulcers.

3-some drugs absorbed mainly from intestine and not stomach.

4-site of action of drug in intestine (worms).

c-Granulationmethod

Tablet contain 7 things , polymer form paste from them them wet granules then drying and put in mashine.eg.sod alignate,acacia,gelatin for binding powder (adhesive agent).

d-Disintegrating agent of tablet

Tablet                                                     therapeutic effect

eg.starch,carboxymethyl starch

 

other dosage forms

1-suspention(thickening agent)

to revent sedimentation of suspention particles.

2-emulsion stability:2 immisible system by act as em. Agent.

3-opthalmic soln:increase contact time bet. Eyedrops and eye(adherance to cornea) eg.me.ce,

4-oint.bases (PEG)

liq PEG(200-600)+solidPEG(>1000)=semisolid consistency.

 

gelatin

collagen of white c.t (skin,bone, of pig)

collagen  on hydrolysis    form gelatin.

Pharmagen A   by acid hyd.  Form gelatin  stable in acid med.

Pharmagen B  by base hyd.  Form gelatin satble in alkaline med.

Uses of gelatin

1-major const. Of hard& soft gelatin capsules.

2-water sol. Sup. Base.(gelatin+water+glycerol).

3-microencapsulation. Particles of powder of any drug coat by gelatin layer  suitable for administration .

 

sustained release

]to overcome frequency of administration.

Drug+polymer embedding of drug throughout matrix of polymer

Drug slowly and regularly released due to polymer

Forms

1-erodible matrix =sheets of polymer (drug +matrix sol in ) viscous matrix

erotion=dissolve y time due to solvent penetration.

2-non erodible

matrix +drug+solvent

solvent dissolve drug and leave matrix intact.

Matrix act as barrier only.

3-barrier resins

drug+viscous soln=barrier against transfere of drug.

Increase viscousity of med to give sustained release.

4-Slightly soluble salts

Decrease sol. Decrease absorption  increase effect time(take longer time)

Polymer is (tannic acid and polygalacturonic acid) +basic drug =salt (slightly soluble )give sustained effect.

 

Polymer drug

Use polymer as adrug