[Kenneth Christianson]

Reply To: Stick Packs/ Pouches

Howdy Sherri,

We’ve recently completed a project using sachets (a slightly larger version of a crystal lite stickpack) on a granule formulation.

Here’s some thoughts as you move forward.

1) Equipment selection – Gravimetric or volumetric filling of stickpacks presents a trade-off between speed and accuracy. Depending on your precision requirements (and/or what the difference is between dose sizes) may guide you to make a decision on gravimetric filling. If you precision requirements are relatively tight (e.g. +/-5 mg), gravimetric filling might be the easiest way to get a prototype out in the clinical phase, and transition later into a volumetric fill later on.
2) Depending on the material you select for your stickpack/sachet, the material characteristics of your granule/powder, and your dosing instructions, more than likely the quantity of material you put into your stickpack will be more than what the patient receives as some residual material stuck inside of the container. Prior to doing the packaging of your clinical material, run a study and produce some data which demonstrates what the average loss is on your high and low strengths. This will help justify whatever overfill you choose to do if you go that route.
3) Formulation – To the extent you are able, consider a formulation which is geared to stick packs/pouches. The flowability of the material will be what serves ultimately as your bottleneck on precision and throughput during packaging.
4) Dose recovery – To the extent you are able, ensure that the in-process testing done during packaging to verify fill weight/volume aligns with the way the Analytical teams will be performing their assay/CU tests, and aligns with the way the patient will be dosing the kit. In other words, if during packaging they are only periodically checking changes in net weight of the pouch, and on the analytical side they are rinsing out the pouch completely, and on the patient side they are simply cutting off the top of the pouch and up-ending it, there’s a disconnect.

I could probably go on for an hour if you wanted to chat more about it. Our first sachet filling project was a learning experience for sure.