In the field of cosmetic efficacy raw material development, the penetration depth of ingredients is not only related to product effectiveness but also closely tied to usage safety. As an efficient penetration enhancement method, the core challenge of micro-needling technology lies in achieving effective transdermal delivery of active ingredients while avoiding damage to deeper skin tissues. Addressing the widespread public concern—"Does micro-needling damage the dermis?"—Hunan Sunshine Bio-Tech Co., Ltd. has always placed safety at the core of its research and development, adhering to a foundation of scientific evidence and repeatedly validating product safety through rigorous experiments. Experimental results show that the measured penetration depth of Hunan Sunshine Bio-Tech's 99% Premium Hydrolyzed Sponge (Sponge Spicule) falls within the optimal safe range of 100–300μm. This not only effectively breaks through the stratum corneum barrier, creating a direct penetration pathway for active ingredients to reach the dermis, but also ensures that it does not reach the vascular distribution area in the superficial dermis, truly achieving "efficient penetration enhancement with safety as the cornerstone."
Experimental Design and Methods
To systematically evaluate the transdermal safety boundaries of Hunan Sunshine Bio-Tech's Sponge Spicule, this study relied on the company's independently established experimental system, focusing on two key safety indicators: ensuring effective penetration of the stratum corneum (target depth ≥50μm) while strictly avoiding excessive penetration (>500μm) to completely eliminate risks such as pain, bleeding, or infection that may arise from reaching the dermal blood vessels. The experiment used Panamanian fragrant pig abdominal skin as an in vitro model due to its similarity in thickness to the human stratum corneum. The skin underwent professional pretreatment to simulate the actual moisture content of the human epidermis. Subsequently, a precision dynamometer was used to simulate the actual pressure applied during human use, vertically pressing Hunan Sunshine Bio-Tech's 99% Premium Sponge Spicule onto the skin surface. After maintaining pressure for a specified time, samples were collected, prepared into frozen sections, and stained with HE. The vertical length of the needle traces was directly observed and precisely measured under a microscope as the actual penetration depth. Each group of experiments was independently repeated five times, with statistical data presented in the form of "mean ± standard deviation," and outliers were excluded to ensure the reliability and reproducibility of the conclusions.
Results and Conclusions
The experimental data clearly show that the actual penetration depth of Hunan Sunshine Bio-Tech's Sponge Spicule remains stable within the range of 162–235μm, with the longest observed value being 213±18μm, demonstrating good batch repeatability and penetration consistency. The average physical length of the Sponge Spicule sample is 250μm, with the actual penetration depth averaging approximately 14.8% lower than the physical length. This depth range (100–300μm) combines dermatological anatomical theory and industry safety consensus, belonging to the recognized safe and effective penetration range: its upper limit (300μm) is well below the starting region of major vascular distribution in the superficial dermis (approximately 300–500μm), while its lower limit sufficiently breaks through the human stratum corneum barrier (thickness 10–40μm), reliably establishing microchannels for the delivery of active ingredients.
The conclusion indicates that Hunan Sunshine Bio-Tech's Sponge Spicule effectively helps active ingredients reach the basal layer to exert their efficacy while fundamentally avoiding the risk of reaching the superficial dermal blood vessels, perfectly balancing efficacy requirements and usage safety. It is a safe and reliable transdermal penetration enhancement solution.
Our Safety Commitment
As a manufacturer specializing in hydrolyzed sponge production, Hunan Sunshine Bio-Tech Co., Ltd. has established "safe penetration enhancement" as an unwavering core principle since its inception. We insist on addressing concerns with science and supporting promises with data. We solemnly assure our partners and users: skin health and product safety will always be prioritized in our R&D decisions. Every micro-needling product we deliver undergoes rigorous validation to ensure it is safe, controllable, and trustworthy.
Looking ahead, we will continue to uphold an evidence-based R&D spirit, continuously advancing in the field of hydrolyzed sponge micro-needling. We are committed to providing global partners with more micro-needling raw material solutions that are both highly effective and verifiably safe. Hunan Sunshine Bio-Tech's Sponge Spicule raw materials, supported by the dual wings of science and safety, will drive every technological breakthrough to become a reliable choice for the industry. This will allow efficacy and safety to truly synergize, injecting enduring confidence into the beauty industry.
