Step 1 — Formulate the fill

Decide what goes inside: a powder blend, pellets, beads or a liquid. The fill's bulk density, flow and compressibility decide everything downstream. Low-density powders need tamping or dosator dosing; liquids need a sealed softgel or a banded hard-shell process. Characterise the fill before choosing any equipment.

Step 2 — Select the shell

Shells run 000 (largest, ~1.37 mL) down to 5 (smallest). Material is gelatin (standard, EU vegetarian lines use HPMC) or softgel for liquids. Size sets the dosing volume and the machine bore; a 00 shell (~0.95 mL) is the common nutraceutical workhorse, 000 for veterinary and high-dose.

Step 3 — Fill

• Manual tray: hand-loaded, 1,500–3,000 caps/hr, RSD 4–7%. Fine for R&D and pharmacy.

• Semi-automatic: mechanical dosing, 6,000–25,000 caps/hr, RSD 3–5%.

• Fully automatic: dosing-disk/tamping/dosator turret, 50,000–200,000 caps/hr, RSD <3%.

Step 4 — Seal or close

Hard-shell: the cap is locked onto the body; for moisture-sensitive products a banding (a gelatin ring at the joint) or an overcap seals it. Softgel: the liquid-filled shell is welded by a wedge and dried. Liquid in hard-shell: requires a specialised sealing/banding step — not a standard filler.

Step 5 — Finish and inspect

Polish to remove dust, then check-weigh for fill accuracy and run a metal detector. For commercial lines this feeds the batch record; for EU export, serialisation enters at the carton stage.

Measured throughput by scale

Compliance across the chain

Every stage answers to EU GMP, FDA 21 CFR 211, CE (Machinery Directive 2006/42/EC) and ISO 9001; device-linked products add ISO 13485. Auditors trace material-contact surfaces, cleaning validation and the fill-accuracy record — the closing/sealing step is specifically checked for joint integrity.

Real cases (anonymized)

• Southeast Asia nutraceutical: scaled from manual trays (3,000/hr) to a semi-auto bench (12,000/hr) for 00 mineral capsules; RSD improved from 6% to 3.8% after a tamping upgrade.

• EU probiotic CDMO: low-density powder, fully automatic dosator line at 28,000 caps/hr, validated fill and banded seal for moisture defence.

• Middle East veterinary: 000 antibiotic, manual-to-semi scale-up; humidity controlled at the closing stage to prevent cap sticking.

Pain points

• Fill variation from uncharacterised powder or wrong dosing method.

• Sealing leaks at the cap-body joint for moisture-sensitive products.

• Scale-up gap — a manual process that does not transfer to automatic settings.

Misconceptions

• "Manual and automatic give the same quality." Accuracy and consistency diverge sharply past a few thousand capsules.

• "Shell size is cosmetic." It sets dosing volume and machine bore.

• "Filling is the hard part." Closing/sealing is where moisture and leak failures appear.

Manual vs industrial

Procurement pitfalls

• Buying a fully automatic line before the formulation and shell are fixed.

• Ignoring the sealing/banding step for moisture-sensitive fills.

• No fill-RSD acceptance criterion written into the equipment SAT.

FAQ

What are the five steps?

Formulate, select shell, fill, seal/close, finish and inspect — in that order.

Which scale should I start at?

Manual for R&D; semi-auto for contract/low volume; fully auto above ~50,000 caps/hr.

How do I seal moisture-sensitive capsules?

Use banding at the cap-body joint or an overcap; for liquids use softgel or sealed hard-shell.

Is manual capsule making GMP-compliant?

Difficult to document at commercial scale; semi-auto or auto is expected for GMP output.

What shell size is most common?

Size 00 (~0.95 mL) for nutraceuticals; 000 for veterinary/high-dose.

Can I fill liquid in a hard shell?

Only with a specialised sealing/banding process — standard fillers handle powder/pellets.

What compliance covers the chain?

EU GMP / FDA 21 CFR 211, CE, ISO 9001; ISO 13485 for device-linked products.

When should I scale from manual to automatic?

When volume reliably exceeds what semi-auto delivers and RSD must be tightly validated.