Modified release
The problem
A single active input gives you a single release curve. For caffeine that means an early peak and an early decline — fine for a pre-workout, wrong for a product that promises sustained focus through a working day. Reformulating around that constraint usually means accepting a compromise curve chosen by whoever made the ingredient.
Why the conventional approach fails
Fixed sustained-release blends are supplied as a single finished profile. If you need 40% immediate and 60% over eight hours rather than the ratio on offer, you cannot get there — and buying two products from two suppliers usually fails for a physical reason rather than a formulation one: populations with different particle size, shape and bulk density segregate during blending, transfer and capsule filling. The dose per capsule then drifts, and the dissolution result stops matching the blend you designed on paper.
Applying a release membrane also costs active loading. An SR-8 pellet carries less active than an SR-4, which carries less than an IR. Ignore that and the capsule gets too large to sell.
How NexaGens addresses it
The pellet platform supplies release profiles as independent modules developed to a matched 500–850 µm target size range, with matched physical properties. You choose the ratio; the physical matching is what keeps the blend behaving as designed through capsule-fill uniformity and segregation control.
This is the most differentiated thing NexaGens supplies, and it is a deliberate architectural choice rather than a coating trick.
Relevant products
| Product | Assay | Release profile | Status |
|---|---|---|---|
| Caffeine IR Pellets | 85% w/w | NLT 80% at 30 min; NLT 90% at 45 min | Qualified |
| Caffeine SR-4 Pellets | 70% w/w | 15–30% at 1 h; 40–65% at 2 h; NLT 85% at 4 h | Qualified |
| Caffeine SR-8 Pellets | 65% w/w | 10–20% at 1 h; 20–40% at 2 h; 45–65% at 4 h; NLT 85% at 8 h | Qualified |
| L-Theanine SR-4 Pellets | 70% w/w | 15–30% at 1 h; 40–65% at 2 h; NLT 85% at 4 h | Qualified |
All figures above are confirmed specification values. Each production batch is supplied with a batch-specific certificate of analysis. Method: Ph. Eur. 2.9.3.
What to specify, and how to test it
- The dissolution method in full — pharmacopoeial reference, apparatus, rotation speed, medium composition, volume, pH and temperature. A release percentage without its method is not comparable to anything.
- Multiple time points, not a single endpoint. “85% at 8 hours” is satisfied by profiles that behave very differently at hour one.
- Batch-to-batch variability at each time point, not a single representative curve.
- Particle size distribution and bulk density for every population you intend to blend. This is what determines whether your blend survives handling.
- Blend-verified dissolution — the profile of the actual ratio you will ship, not the arithmetic sum of the individual curves.
- Coating integrity after processing — capsule filling and tableting can damage a release membrane. Ask for post-process dissolution.
Next steps
See the functional pellet range · Discuss a blend ratio with our technical team