Research
Parilla Guard explores perilla seed extract as a natural alternative to conventional mineral UV filters such as Oxybenzone (Benzophenone-3, BP-3), Octinoxate (Ethylhexyl methoxycinnamate), 4-Methylbenzylid Camphor (4MBC) and Butylparaben, which are known to cause coral reef bleaching and environmental accumulation. Our research focuses on developing biodegradable, plant-based sunscreen formulations that maintain high SPF and PA performance while being safe for marine life and ecosystems.
Through systematic extraction, formulation, and SPF testing, Parilla Guard demonstrates how natural bioactives can deliver photoprotection comparable to synthetic compounds — without the ecological cost.
This research is conducted under the guidance of
Asst. Prof. Narongrit Lah-Pun, Faculty of Science and Technology, Phranakhon Rajabhat University, who serves as the consultant for this research project.
Extract Procedure and UV Absorption Analysis
Perilla seed extracts were prepared into 3 samples using ethanol (50%, 70%, 95%) to identify the most efficient method. Perilla seed samples were sealed, shaken, and left to ferment, then filtered and concentrated using a rotary evaporator at 15°C to obtain purified extracts.
The resulting extracts showed strong UV absorption under UV-VIS analysis, highlighting their potential as natural, coral-safe alternatives to traditional substances in sunscreens.
Sunscreen Base Formulation
A balanced oil-in-water emulsion was developed to serve as the base for Parilla Guard sunscreen. The water phase (with Carbopol 940 and Butylene Glycol) provides moisture and stability, while the oil phase (with Emulgade 165, Olive Oil Extract, Lipid Soft SPF, and Silica Sunsphere H53) enhances UV protection and texture.
Both phases were heated to 75 °C and blended using a high-speed homogenizer to achieve a smooth, stable cream ready for SPF testing.
Stability & SPF Testing
Two sunscreen formulas — one base and one with 1% Perilla seed extract — were mixed at 3,000 rpm for 15 minutes and analyzed for pH, viscosity, color, and cream stability (CI). SPF values were measured to determine UV-protection efficacy. Results showed that the 95% ethanol extract achieved the highest SPF, confirming a greater concentration of natural UV-absorbing compounds.
Parilla Guard sunscreen achieved SPF 32.06 ± 9.03, providing broad-spectrum, UV protection verified by laboratory testing.
Skin Safety Test
To ensure both skin safety and consumer acceptance, Parilla Guard underwent comparative patch testing on human volunteers. Two cream samples — one with and one without Perilla seed extract — were applied on marked skin sections under transparent patches.
Measurements of skin redness, moisture loss, and color variation were recorded using precision instruments including the Mexameter MX18, Tewameter TM300, and Skin-Colorimeter CL400.
Results showed no irritation or allergic response, and participants reported a light, comfortable texture. These findings support the extract’s suitability as a biocompatible, eco-safe ingredient in next-generation sunscreens.
