Skip to content
Rglax Pharma

Coating systems

Ten systems, one brand

Start from the job the coat has to do. Each system page carries the grades in that range, the application parameters and the actives those grades are formulated for.

Choose by the job, not by the code

Choosing

Start from the problem, not the product list

Ten systems sounds like a lot until you sort them by what they are actually for. Four questions get you to the right one.

Does the tablet only need covering and a finish?

Film coating. Aqueous where the core allows it, non-aqueous where it does not, extra white where the core shows through. Sugar film and metallic sit here too, as finishes rather than functions.

Is the active destroyed by stomach acid?

Enteric coating, over a seal coat if the core is acid labile. Which enteric grade depends on the polymer your filing names, which is why we hold four separate bases.

Does it pass release but drift on stability?

Moisture barrier. The film is doing shelf life work rather than cosmetic work, and it is judged on stability data rather than on gloss.

Does it fail on the press rather than in the pan?

Then the answer is not a coating at all. A hygroscopic adsorbent goes into the powder before compression, and a dissolution enhancer corrects disintegration time at the same stage.

At a glance

All ten systems compared

Grades held, the process base each one runs on, and the job it does.

SystemGradesProcess baseWhat it is for
Film coating5Aqueous, Non-aqueous (solvent), Aqueous or non-aqueousAqueous and non-aqueous film coats, formulated to your application and regulatory requirement.
Enteric coating5Non-aqueous (solvent), AqueousDelayed release polymers on methacrylic, phthalate and CAP bases for aqueous or organic processing.
Moisture barrier4Non-aqueous (solvent)HPMC and PVA based immediate release systems that protect against light, moisture and environmental gases.
Seal and pre-coat2Aqueous or non-aqueousTransparent and coloured sub-coats that prepare the core for enteric or functional layers.
Sugar coating1Non-aqueous (solvent)Fully formulated HPMC sucrose based systems for a classic sugar coated finish.
Metallic and pearl1Non-aqueous (solvent)Non-aqueous metallic and pearl effect film coats, shade matched to your reference sample.
Sustained release1Dry blendControlled release drug delivery blends for extended release solid dosage forms.
Taste mask1Dry blendMasking the taste and odour of bitter actives in suspensions and dispersibles.
Dissolution1Dry blendDissolution enhancer blends for disintegration time and dissolution correction.
Hygroscopic adsorbent1Dry blendAdsorbent material for hygroscopic drugs that create problems during and after compression.

Parameters

Two temperature bands, not one

Every system here runs one of two bands, and the gap between them is the largest single difference between the ranges.

Film, seal, sugar, metallic, moisture barrier and sustained release all run the film coating band. On an aqueous dispersion that is 35-40 / 30-35 degrees at the tablet bed against 75-80 / 60-65 at the inlet, the first figure in each pair being the aqueous route and the second the non-aqueous one.

Every enteric grade runs a third band entirely, 30 to 32 degrees at the bed against 45 to 50 at the inlet. That is not a preference. A bed run warmer softens the polymer as it lands, the film coalesces unevenly, and the weak points that creates are invisible on a finished tablet and decisive in an acid stage.

Drying capacity falls with the inlet temperature, so an enteric stage takes longer than a film coating stage of the same build-up. Pushing the spray rate to recover that time puts liquid into a bed that cannot clear it, which produces picking rather than a faster batch.

Why an enteric coat runs cooler than a film coat covers this in full, and every system page carries the parameter table for its own range.

Common questions about coating systems

Start from the job the coat has to do rather than from the product list. If the tablet only needs covering and a finish, that is film coating. If the active is destroyed by stomach acid, that is enteric. If the product passes release but drifts on stability, that is a moisture barrier. If it fails on the press rather than in the pan, the answer is an adsorbent and not a coat at all.

An immediate release film only has to form, adhere and look right. An enteric film has to form and then stay impermeable to acid. A bed run warmer than 30 to 32 degrees softens the polymer as it lands, and the film coalesces unevenly. Those weak points are invisible on the tablet and decisive in an acid stage.

Rarely, and the exception proves the rule. UZ1 disperses in either water or solvent, so it spans both film coating routes. Everything else is formulated for one job, because a film optimised for barrier performance is not the film you want when dissolution is the constraint.

Not every one, but under an enteric coat on an acid labile core it is not optional. The seal isolates the core from the enteric polymer and gives the functional film an even surface to build on. On a robust core going under a plain film coat, it is usually unnecessary.

Three of the ten. The taste mask goes into a suspension formulation, the dissolution enhancer and the hygroscopic adsorbent go into the powder before compression. None of them have coating parameters, because nothing is being coated.

Grades outside these ten can be developed against your specification. Send us the core composition with the shade reference and the coater you will run it on.

Call usWhatsApp