THE LAYER ARCHITECTURE
Dual-Layer Peptourbillon™: retatrutide and thiamine separation
The Peptourbillon™ is the answer to a simple constraint: retatrutide and thiamine must share one cartridge and one reconstitution event, but they must not spend their shelf life as one premixed liquid. Inside the protected lyophilised chamber of Lyoprester SS™, the two actives form a dual-layer cake — a 5 mg retatrutide lower layer and a 20 mg thiamine upper layer with a distinct interface between them.
The layers share the same lyophilisation cycle and the same final cartridge. What they do not share is a solution phase: from filling to activation, each active keeps its own stratum, its own microenvironment and its own stability behaviour.
The seven-step build
- 1
Retatrutide liquid introduced
The retatrutide-containing peptidic liquid is introduced into the protected Lyoprester SS™ chamber first.
- 2
Lower layer frozen
The peptidic liquid is frozen to create the solid retatrutide lower layer — the foundation of the cake.
- 3
Thiamine layer positioned
A separately prepared supercooled thiamine-containing liquid is positioned over the frozen retatrutide layer.
- 4
Two frozen layers, spatially separated
Both layers are frozen while preserving their physical identity — two strata, one interface.
- 5
Co-lyophilisation
The two frozen layers are lyophilised together in the same protected chamber, retaining their layered structure as a dual-layer Peptourbillon™.
- 6
0.5 mL P-EARLs™ activation
The separate P-EARLs™ chamber holds the 0.5 mL reconstitution vehicle until the moment of use.
- 7
Rapid unified reconstitution
Activation reconstitutes both layers into one short-lived preparation immediately before the single shot.
Why separation matters
Separation converts a compromise into a sequence. In storage, each layer can be lyophilised and kept under conditions suited to its own chemistry rather than a shared liquid least-common-denominator. The single-shot architecture also avoids long-term storage of retatrutide and thiamine as one ready-mixed liquid — the mixture exists only for the short interval between activation and administration.
What must still be demonstrated
- Physical integrity and reproducibility of the dual-layer cake across batches.
- Interlayer migration during freezing, lyophilisation and storage — and interface integrity over the shelf life.
- Retatrutide stability in the lower layer and thiamine stability in the upper layer, including oxidation and light sensitivity.
- Rapid and complete reconstitution of both layers with 0.5 mL P-EARLs™.
These are named pillars of the Reta-B1 testing programme; the reconstitution chemistry is detailed on the P-EARLs page.