Glass ampoules remain the packaging of choice for injectable pharmaceuticals, precision cosmetics, and diagnostic reagents: they are chemically inert, tamper-evident, and hermetically sealed. But filling a container with a 1–2 mm neck opening and sealing it with molten glass — thousands of times per hour, without contaminating the contents — takes specialised equipment. This guide explains how an ampoule filling and sealing machine actually works, stage by stage.

The four stages of ampoule filling

1. Feeding

Empty ampoules arrive in bulk and must be presented to the filling needles one at a time, upright, at a steady rhythm. Modern machines use a rectangular feeding system: ampoules travel along a conveyor track and are picked into individual stations. Feeding is where cheap machines fail first — misaligned ampoules cause breakage, spillage, and line stops.

2. Filling

Dosing needles descend into the ampoule neck and dispense an exact volume. Fill accuracy is the single most important specification for pharmaceutical buyers: regulators require tight tolerances, and over-filling wastes product on every cycle. On a PLC-controlled machine, fill volume is adjustable from the control panel — operators can switch between 1 ml, 2 ml, 5 ml, 10 ml, and 20 ml specifications without mechanical rebuilds.

Machines are classified by needle count: 2-needle machines fill two ampoules per cycle, while 4, 6, and 8-needle models multiply output accordingly. A 6-needle machine typically produces 8,100–12,000 ampoules per hour; an 8-needle model suits large-scale pharmaceutical production. For a complete comparison of needle counts, see our ampoule filling and sealing machine buyer guide.

3. Pre-heating and sealing

Immediately after filling, the ampoule neck passes through oxy-gas flames that soften the glass. There are two sealing methods: tip-seal (drawing the molten tip closed with grippers, producing the classic pulled point) and pull-seal. A correct seal is smooth, uniform, and free of capillary channels or carbon deposits. Seal quality determines whether the contents stay sterile for their entire shelf life — well-tuned machines achieve pass rates around 98%.

4. Discharge

Sealed ampoules are collected for inspection and downstream processing — leak testing, ink printing, labeling, and packing.

What happens before filling: washing and drying

Pharmaceutical GMP standards require ampoules to be washed and depyrogenated before filling. A complete ampoule filling line pairs the filler with an ultrasonic ampoule washing machine and a tunnel drying oven that sterilises ampoules and destroys pyrogens at high temperature. Buyers planning a new facility usually purchase all three machines together so the handoff between stages is engineered as one system.

Specifications that matter when comparing machines

Output (ampoules per hour) at your actual fill volume — not just the headline maximum. Fill accuracy and how it is adjusted. Ampoule size range (1–20 ml compatibility means one machine covers multiple products). Contact-part material (FDA-compliant stainless steel for pharma). Control system — PLC control means operators can add or remove process steps themselves, with no specialist programmer required. Gas consumption: filling and sealing machines need fuel gas and oxygen, so factor supply into facility planning.

Frequently asked questions

How many ampoules can a filling machine produce per hour?
From roughly 3,000/hour for a 2-needle machine to over 12,000/hour for 6–8 needle models, depending on ampoule size.

Can one machine handle different ampoule sizes?
Yes — quality machines convert between 1 ml and 20 ml formats with changeover parts and PLC program adjustments.

Do these machines run continuously?
Cast iron construction machines are built for 24-hour continuous operation, with weekly scheduled maintenance.

Can the machine be customised for a specific ampoule shape?
Yes — see our custom orders service. Lead time is approximately 60 working days for modified machines versus 40 for standard.