Exam aid · Calculations and formulas

QC Tests & Pharmacopoeial Limits

The numbers behind tablet, capsule and sterile product quality control, stability testing and sterilisation.

Tables to memorise

Cover the right-hand column and test yourself before checking.

Test	Limit
Disintegration: uncoated tablets	15 min
Disintegration: film-coated	30 min
Disintegration: sugar-coated	60 min
Enteric-coated	Intact 2 h in 0.1 M HCl, then disintegrate in pH 6.8 buffer within 60 min
Dispersible / soluble tablets	3 min
Effervescent tablets	5 min
Friability	≤ 1% weight loss
Uniformity of mass: ≤ 80 mg	± 10%
Uniformity of mass: 80–250 mg	± 7.5%
Uniformity of mass: > 250 mg	± 5%
Content uniformity trigger	< 25 mg or < 25% of unit weight
Dissolution S1	Each unit ≥ Q + 5%

Item	Standard
Autoclave	121 °C for 15 min (saturated steam)
Dry heat	160 °C for 2 h (or 170 °C 1 h, 180 °C 30 min)
Depyrogenation	About 250 °C for ≥ 30 min
Sterilising filter	0.22 µm
Sterility test incubation	14 days
Media	Fluid thioglycollate (30–35 °C); soya-bean casein digest (20–25 °C)
Endotoxin test	LAL (gel clot, turbidimetric, chromogenic)
Biological indicator (steam)	Geobacillus stearothermophilus
Biological indicator (dry heat, EtO)	Bacillus atrophaeus
Isotonic	0.9% NaCl; −0.52 °C freezing point

Condition	Value
ICH long-term (zone II)	25 °C / 60% RH
Zone IVa long-term (e.g. Pakistan)	30 °C / 65% RH
Zone IVb long-term	30 °C / 75% RH
Accelerated	40 °C / 75% RH for 6 months
Refrigerated	2–8 °C
Cool place	8–15 °C
Shelf life definition	Time to fall to 90% of label claim
Type I glass	Borosilicate; all parenterals
Type II glass	Treated soda-lime; acidic and neutral aqueous
Type III glass	Soda-lime; non-aqueous and dry powders

Friability over 1%, or any broken tablet, fails the test.
Membrane filtration removes bacteria but not endotoxins or most viruses.
Accelerated stability: 40 °C/75% RH; a 5% assay change is a 'significant change'.
Moist heat kills by protein coagulation; dry heat by oxidation.
Multi-dose injections contain a preservative; large-volume parenterals do not.

15–30–60 for disintegration: Uncoated 15 min, film-coated 30 min, sugar-coated 60 min.
121 for 15, 160 for 120: Autoclave 121 °C/15 min; dry heat 160 °C/120 min.

Attempt MCQs on these topics while the sheet is fresh. Anything you get wrong goes to your incorrect list for the next round.