The effect of sucrose palmitate characteristics as a surfactant on the physical stability of red palm oil submicroemulsions

Submicroemulsions are delivery systems that can enhance the solubility and stability of lipophilic compounds, such as red palm oil (RPO). This study aimed to evaluate the effects of sucrose palmitate (surfactant) on the characteristics and stability of RPO submicroemulsions. Four sucrose palmitate surfactants (SP1–SP4) with varying ester concentrations and hydrophilic–lipophilic balance (HLB) values were evaluated. Submicroemulsions were characterized based on globule size, polydispersity index (PDI), and zeta potential. Several methods were used to evaluate stability. These included a cycling test, three temperature conditions (5°C ± 3°C, 30°C ± 2°C, 40°C ± 2°C), Ostwald ripening rate, and a Lumifuge test. The results were analyzed using SPSS. Initial results showed that SP3 and SP4, with HLB values of around 17, produced the best globule characteristics, namely globule size below 180 nm, PDI below 0.15, and zeta potential 0.05). This finding confirms that initial emulsification efficiency does not always correlate with stability. Furthermore, optimal stability of SP1 was found at 30°C ± 2°C, while SP4 was more stable at 5°C ± 3°C, indicating that differences in internal formulations influence the specific thermal behavior of the formulations. The characteristics of sucrose palmitate significantly influence the quality of the submicroemulsion. SP1 and SP4 are the best candidates for development into pharmaceutical products.