Silicone-Free Lip Balms: The Impact of Cooling Times and Temperatures on Performance

This study explores whether optimising post-moulding cooling can enable replacement of multi-domain silicones (MDSi) with biodegradable polyglycerol esters (PGE) in lip balms without altering the base composition. A silicone-based benchmark, cooled at 4 °C for 30 minutes, was compared with silicone-free formulations cooled under fridge, freezer, and room temperature protocols. Instrumental testing measured hardness, pay-off, yield strain, and melting enthalpy. Results showed that although none of the silicone-free samples fully matched the benchmark, the freezer-cooled variant (−20 °C, 7 min) achieved the closest similarity, with strong hardness, balanced pay-off, and the highest resemblance score, while also reducing production time by 76.6%. These findings demonstrate that cooling optimisation is an effective, low-cost strategy for improving the performance of silicone-free formulations, offering a practical path toward more sustainable lip balms. Sensory evaluation will be required to validate consumer experience.