HARD GELATIN CAPSULES
(HGC)
What are Capsules?
¾ Solid dosage form most common after Tablets
Limitations
¾ Not useful for highly soluble drugs e.g. KBr,
NH4Cl
¾ Highly efflorescent or deliquescent materials
Types of Capsules
¾ Hard Gelatin Capsules (HGC)
¾ Hard non-flexible shells
¾ for filling granules, pellets, tablets or liquids
¾ Soft Gelatin Capsules (SGC)
¾ more flexibility in size and shape
¾ Suitable to fill semisolids and oil solution and
suspensions
Gelatin
¾ Translucent, colorless, brittle, nearly tasteless
¾ Heterogeneous mixture of single or multi-stranded
polypeptides solid substance
¾ partial hydrolysis of collagen extracted from the
bones and connective tissues of animals like cattle &
horses
¾ Gelatin melts when heated and solidifies when
cooled again
¾ Types of gelatin
¾ Type A: Acid-treated - Pig skin collagen 10-48 hr
¾ Type B: Alkali-treated - Bovine hides, Calf skin 6-
12weeks
Structure of Gelatin
Gelatin contains many glycine (almost 1 in 3
residues, arranged every third residue), proline and 4-
hydroxyproline residues. A typical structure is -Ala-
Gly-Pro-Arg-Gly-Glu-4Hyp-Gly-Pro-.
Gelatin Manufacture
1.
Pretreatment:
¾ Size reduction, washing, removing hair from
the hides and degreasing
2.
Extraction:
¾ With Hot water, Acid treatment
¾ Reducing cross linkages between collagen
¾ Removing impurities like fat and salts
3. Recovery:
¾ Filtration, Evaporation, Drying, Grinding,
Sifting
Manufacture of Capsule shells
¾ Formation of gelatin slurry
¾ Dipping of pin-bars in slurry
¾ Rotation of pin bars with simultaneous drying
¾ Cutting the formed shells to required size
¾ Assembling body and cap to close them loosely.
HGC Sizes and Filling Capacities
156
130
104
78
0.10
5
252
210
168
126
0.21
4
360
300
240
180
0.30
3
444
370
296
222
0.37
2
600
500
400
300
0.50
1
816
680
544
408
0.68
0
936
780
624
468
0.78
0el
1092
910
728
546
0.91
00
1224
1020
816
612
1.02
00el
1644
1370
1096
822
1.37
000
1.2
1.0
0.8
0.6
Capacity (mg)
Powder density gm/ml)
Volume
(ml)
Size
Formulation P