A pharmaceutical suspension is synthesized such that a significant amount of salt is formed during neutralization. This micro-fine suspension is washed out of salt by diafiltration and further concentrated. Initial salt concentration is about 10 % and the active ingredient is around 3.5 %. The desired final concentration is almost no salt (< 0.1 %) and 7.5 % active ingredient.
The fineness of the suspension requires microfiltration. With conventional crossflow technology a further concentration of the suspension is impossible due to the high viscosity. Therefore, dynamic crossflow filtration is required. Systems with rotating ceramic discs have too low throughput and require 100 m² filter area. Hence the BoCross Dynamic Filter is the only available technology for this challenging separation task.
Three 8 m² BoCross Dynamic Filters are applied for thickening and washing of this viscous suspension achieving the target values of 7.8 % active ingredient and 0.1 % salt.
BoCross Dynamic Filter L8 – Hygenic Design
Units installed |
|
3 |
Filter area per unit |
[m²] |
8 |
Material |
[ - ] |
1.4435 (316 L) |
Filter drive power |
[KW] |
20 |
Foot print |
[m²] |
2 |
Year of commissioning |
[ - ] |
2 units in 2008 / 1 unit in 2016 |
Process and Operation Data
Solids content in feed |
[wt- %] |
3 |
Solids content in retentate |
[wt- %] |
7.8 |
Solids content in filtrate |
[g/l] |
Free of particles |
Washing out of salt |
[–] |
1 : 100 |
Operation pressure |
[bar, g] |
1.5–3.0 |
Product Data
Product | Iron hydroxide (pharmaceutical product) | |
Range of particle sizes | [µm] | 1–50 |
Flow behaviour | | thixitropic |