For sunscreen formulators, achieving a higher SPF is only part of the challenge. UV filter systems must also provide broad-spectrum protection, maintain stability and address concerns around skin penetration, while meeting expectations for formulation ease and skin feel.
Uniproma’s Sunsafe® Fusion C4 and C5 approach these requirements through lipid microsphere encapsulation. Multiple organic UV filters are combined within a pre-dispersed carrier designed to support more uniform distribution and synergistic UVA and UVB protection.
In comparative testing at identical UV filter content, Sunsafe® Fusion C4 achieved a 62% higher in vitro SPF and a 57% higher PFA than the corresponding free UV filter system. Sunsafe® Fusion C5 delivered increases of 59% and 56%, respectively. These results demonstrate the potential of encapsulation to improve protection performance without increasing UV filter content in the tested systems.
Characterisation of the microspheres showed a narrow particle-size distribution, with a Z-average of 337.4 nm and a polydispersity index of 0.033. Stability testing also found that particle size, appearance and UV filter content remained essentially unchanged after three months under multiple storage conditions.
The delivery system was further investigated in a fluorescent tracer study using rhodamine B (RhoB). After eight hours, free RhoB reached a depth of 413 μm, whereas RhoB carried within Sunsafe® Fusion C4 remained within the stratum corneum and upper epidermis, reaching 79 μm. The findings indicate more superficial distribution of the encapsulated tracer under the study conditions.
Together, these results highlight the potential of lipid microsphere encapsulation to bring protection performance, dispersion stability and controlled delivery into an integrated UV filter system. The pre-dispersed format also supports convenient incorporation into sunscreen formulations.
Uniproma will present Sunsafe® Fusion C4 and C5 at in-cosmetics Asia 2026, taking place on 3–5 November at BITEC in Bangkok, Thailand. Visitors to Booth AA50 can explore the technology, try sunscreen prototypes to experience their skin feel firsthand, and meet the team to discuss applications in their next formulation.
