Primary Packaging & Filling

Stick-Pack & Sachet

Single-dose flexible packets — a slim stick or a flat sachet — formed on FFS machines from barrier film. At single-serve, the net weight is the dose, so small-fill accuracy is a content-uniformity question.

This page’s family — the operations that form, fill, and seal product into its primary container, which is where stick-packs and sachets are made.See the other primary packaging & filling technologies The single-dose powder that fills a stick-pack is dried, granulated, and blended upstream — engineered to flow and dose evenly — in the drying and particle engineering family.See the drying & particle engineering technologies Once formed, filled, and sealed, the packets are coded, cartoned, cased, and shipped downstream in the labeling and secondary packaging family.See the labeling & logistics technologies
What it is

One serving, sealed in barrier film.

Stick-packs and sachets are small single-dose flexible packages. A stick-pack is a narrow, tall tube — typically three-side or fin-sealed — for one serving of powder or liquid; a sachet is a flat four-side-sealed packet for the same. Both are made on FFS machines from barrier film and built around single-dose convenience and barrier protection of a small fill.

The format is all about the single serve — pocketable, pour-and-go, fresh every time — which puts unusual weight on getting a very small fill exactly right and sealing it perfectly.

The levers are fill accuracy at small dose, seal integrity, film barrier, and machine speed. The small target is the hard part: at single-serve, a fill that drifts a fraction of a gram is a dose that drifts — and a hygroscopic powder behind a marginal seal spoils fast because there’s so little of it.

Barrier film is specified for the small, often hygroscopic fill, formed on stick or sachet FFS with longitudinal and end seals, dosed to the single-serve net weight, then sealed, cut, and coded into individual units.

Process flow
1

Barrier film specified for the small, often hygroscopic single-dose fill

2

Formed on (vertical) stick or sachet FFS; longitudinal and end seals made

3

Dosed (auger/volumetric for powder, pump for liquid) to the single-serve net weight

4

Sealed and cut to individual units; coded

Single-dose stick-packs or sachets

The leversFill accuracy at small dose, seal integrity, film barrier, and machine speed.
Why it matters

At single-dose, the net weight is the dose.

Because each pack is one serving, fill accuracy on a small target is a content-uniformity issue, not just a fill question — an under- or over-filled stick is an under- or over-dosed serving. And a hygroscopic powder makes barrier and seal integrity critical, because a tiny leak ruins a small fill fast: there’s no margin to absorb moisture ingress.

High line speeds make marginal seals and fill drift easy to miss without monitoring — the failures are small and frequent rather than dramatic. The discipline is tightly monitored small-dose fill weight tied to content-uniformity needs, seal-integrity testing on the narrow stick and sachet seals, a barrier film matched to the fill’s sensitivity, seal-zone contamination control at speed, net-content verification across the run, and film substitutions requalified for barrier.

21 CFR 174–178 · food-contactThe food-additive rules for food-contact substances — the barrier film and sealant that touch the product must be cleared for that use, so the package does not migrate into the single-dose fill.
21 CFR 211.94 · container-closureThe drug CGMP rule for container-closure systems — for a drug in a stick-pack or sachet, the film-and-seal packet is the container-closure that must protect the dose and not react with or add to it.
USP <905> · uniformity (drug)The uniformity-of-dosage-units standard — at single-serve the net weight is the dose, so each packet has to hold its target amount within the allowed spread for the drug it carries.
21 CFR 101.7 · net quantityThe net-quantity-of-contents declaration — the amount you print on the stick-pack has to match what the dosing system and checkweigher actually put in each single-dose packet.

Food-contact film under 21 CFR 174–178; drug single-dose uniformity under USP <905>; net-content accuracy and seal integrity anchor the rest.

How it compares

Why a maker chooses single-dose — and what they trade.

The stick or sachet sells convenience and freshness per use. Knowing the choices around it tells you the cost.

vs.

Stick vs. sachet

Sticks are slim and pocketable (pour into water); sachets lay flat and tear open.

The tradeThe choice is ergonomic and graphic — both face the same fill and seal discipline.
vs.

Multi-dose pouch or bottle

A multi-dose pack is cheaper per gram.

The tradeSingle-dose guarantees dose accuracy and freshness per use, at higher packaging cost per gram.
vs.

Effervescent tube / capsule

Tubes and capsules are alternative single-dose formats.

The tradeThey carry different barrier and reclosure needs than a sealed stick or sachet.
Where it tends to go wrong

The gaps a reviewer looks for on a stick or sachet.

None of these are exotic. They’re the quiet places small fills and narrow seals drift unseen — recognizable the moment you’ve run a stick machine.

Small-dose fill weight isn’t tightly monitored — at single-serve, weight is the dose.

Seal integrity on narrow stick seals isn’t tested — leakers ruin a small fill quickly.

The barrier film is inadequate for a hygroscopic or oxygen-sensitive single dose.

Powder bridging or contamination in the seal zone at high speed.

Net-content compliance across the run isn’t verified.

Film substitution without barrier requalification.

If this is your operation

Six things to check against your own records.

Not an audit — a read you can run yourself before anyone else does. Pull one recent run and walk it.

01

Ask how single-dose fill weight is monitored and whether it meets content-uniformity needs.

02

Check seal-integrity testing on the stick and sachet seals.

03

Confirm the barrier film suits the fill’s sensitivity.

04

Review seal-zone contamination controls at line speed.

05

Look at net-content verification across the batch.

06

Verify any film change was requalified for barrier.

Applications

The same format, across very different fills.

The fill changes — the discipline never does: nail the small dose, test the narrow seal, match the barrier.

Supplement

Powder & electrolyte sticks

Single-serve drink-mix, electrolyte, and greens sticks, where small-dose accuracy and moisture barrier are the controls.

Pharma / OTC

Unit-dose powders & granules

Single-dose oral powders and granules where net weight maps directly to drug content uniformity.

Food & beverage

Condiment & instant sachets

Sugar, coffee, condiment, and seasoning sachets, where fill accuracy and seal hold across a fast line.

Cosmetic

Sample & single-use sticks

Single-use cosmetic and personal-care sticks and sachets, where the barrier protects a tiny fill to point of use.