This work aimed to study the stability by thermal cyclization of solid lipid microparticles (SLMs) loaded with ascorbic acid (AA). It studies thermal cyclization stability, SLMs were submitted to storage in stress conditions at two alternating temperatures (30 and 45°C) for 48 hr each cycle. The particles were characterized by thermal behavior using DSC, polymorphism, AA retention levels, and AA retention kinetic modeling. The analyses were performed on days 0, 7, 15, 30, and 45 of storage. At the end of the 45th day, the SLMs presented good AA retention values, equivalent to 76.39%, 74.25%–83.07%, respectively, for F1, F2, and F3. The results indicate that all the SLMs had controlled release and followed the Higuchi kinetic model, and the melting peaks remained stable throughout the storage period. The polymorphic analysis revealed that the β' crystals type was predominant in all the formulations studied.
Novelty impact statement
For the application of solid lipid microparticles (SLMs), it is necessary to study their physical stability during storage. The use of temperature fluctuations (thermal cyclization) allows the study of the polymorphic, thermal, and retention behavior of the asset in the SLMs. The particles obtained in this work proved to be stable (controlled release by Higuchi model) when subjected to thermal stress during the 45 days of storage, with AA retention ranging from 74.25% to 83.07%, β' crystals, and invariable melting properties.