Acetyl Hexapeptide-38 Cream

In formulations for lip care creams, nourishing balms, and lip serums, Acetyl Hexapeptide-38 cream has demonstrated excellent results in enhancing lip volume and improving lip texture. A randomized, double-blind, controlled trial involving 87 subjects showed that an emulsified cream formulation containing 2% acetyl hexapeptide-38 resulted in an 18% increase in lip volume and a 22% improvement in lip contour refinement after 28 days of continuous use, along with improvements in lip line depth and lip discoloration.It offers excellent textural compatibility and can be synergistically combined with moisturizing and skin-softening excipients such as squalane, shea butter, vitamin E, and sodium hyaluronate.

In daily repair and anti-aging compound cream formulations, this ingredient can be synergistically combined with moisturizing agents such as sodium hyaluronate, repairing peptides such as palmitoyl pentapeptide-4, as well as antioxidants like ergothioneine and vitamin C derivatives. This synergy not only preserves its core plumping and firming benefits but also helps enhance skin barrier stability and address multiple skin concerns, including roughness, sagging, dullness, and photoaging. In blended formulations, attention must be paid to the optimal pH ranges and temperature tolerance of each active ingredient.

The skin around the eyes is only about 0.5 mm thick, with a thin subcutaneous fat layer, making it prone to volume loss issues such as tear trough depression, orbital atrophy, and sagging under-eye bags. Eye-specific creams or serums containing 1%–1.5% Acetyl Hexapeptide-38 can gently promote the restoration of subcutaneous fat volume around the eyes, improving the appearance of tear trough hollows and orbital aging, while also helping to reduce dry lines, fine lines, and skin laxity. A 28-day trial of an eye care formulation showed that products containing this active peptide increased skin hydration around the eyes by 12%, improved elasticity scores by 9%, and achieved an 81% satisfaction rate among participants regarding firmness and plumpness around the eyes.

The skin on the neck has few sebaceous glands and low collagen density, making it prone to signs of aging such as deepening neck wrinkles, sagging skin, and a "turkey neck"; The skin on the hands, due to prolonged exposure to UV rays, detergents, and environmental irritants, is prone to issues such as fat atrophy on the back of the hands, prominent veins, and dry, sagging skin. Formulations of neck repair creams and hand nourishing creams containing 1.5%–2% acetyl hexapeptide-38 can improve skin dryness, sagging, and blurred contours in the neck and hands by promoting the restoration of local fat tissue volume, while simultaneously enhancing skin hydration and elasticity.

Under storage, transportation, and static conditions, the emulsion system of this cream formulation may undergo phase separation, manifested by the oil phase rising to the surface to form a thin oily layer and the aqueous phase sinking, resulting in stratification of the cream's consistency and a loss of overall texture uniformity. Rheological parameters may deviate from the design range, specifically manifested as a decrease in yield stress, abnormal fluctuations in plastic viscosity, and thixotropic abnormalities such as clumping, solidification, or an increased granular feel in the ointment.

Within the stated shelf life, the formulation may exhibit shelf-life abnormalities such as premature deterioration and loss of efficacy of active ingredients, manifested by active peptide content falling below the lower limit of the labeled amount and physicochemical indicators exceeding acceptable ranges. When storage conditions-such as protection from light, constant temperature, and dryness-do not meet standards, ultraviolet (UV) exposure can accelerate the photooxidative degradation of active peptides; temperature fluctuations can catalyze hydrolysis reactions and phase separation; and excessively high ambient humidity can promote moisture penetration into the packaging.

The fatty components, surfactants, and active peptides in the cream may interact with packaging containers (such as polyethylene, polypropylene, acrylic, and coated glass bottles), leading to swelling, stress cracking, reduced transparency, and surface haze in the packaging materials. Ingredients in the formulation may migrate and adsorb onto the packaging materials, resulting in a loss of active peptide content and an imbalance in the ointment's formulation ratios. Low-molecular-weight additives in the packaging materials (such as plasticizers, antioxidants, slip agents, and residual monomers) may migrate in the opposite direction into the ointment.

Microbial growth can lead to macroscopic manifestations in the ointment, such as visible colonies, turbidity, gas production, abnormal pH fluctuations, and characteristic off-odors. The efficacy of the preservative system may decline due to competitive adsorption by active ingredients, pH drift, or migration from packaging, resulting in a narrowed antimicrobial spectrum and an increase in the minimum inhibitory concentration, thereby failing to effectively inhibit microbial proliferation.The sterilization strategy for this cream formulation employs a tiered sterilization approach based on the varying heat resistance of each component.

The standard sterilization method involves preparing a concentrated solution of the active peptides with sterile purified water, followed by sterile filtration through a 0.22 μm pore size polyethersulfone (PES) or polyvinylidene fluoride (PVDF) microporous filter membrane.The filtrate is collected under sterile conditions and stored at low temperature; Alternatively, pharmaceutical-grade raw materials that have been sterilized and verified to meet microbial limit requirements may be procured directly and weighed and added under aseptic conditions. For powdered excipients, the sterilization method-dry heat, ethylene oxide (EO) sterilization, or γ-ray irradiation.

After sterilization, it is necessary to verify that the physical properties of the packaging materials (such as seal integrity, elasticity, and transparency) have not deteriorated and to ensure that sterilant residues comply with pharmacopoeial limits.All internal surfaces in direct contact with the ointment must be sterile. Sterilized packaging materials should be used within their expiration date to prevent secondary contamination. Regarding the production environment, the filling of non-sterile ointments is typically performed in a Class D cleanroom, while ointment formulations claimed to be sterile must be filled and sealed under Class A unidirectional laminar flow protection within a Class C background environment.

Operators must undergo a sterile changing procedure, disinfect their hands, and wear sterile gloves before entering the operating area.The entire process must strictly adhere to aseptic operating procedures to minimize the risk of microbial contamination.The formulation process for this ointment must be conducted under sterile conditions with strict control of temperature and the sequence of ingredient addition. After the oil phase and water phase have been sterilized separately, they are heated to 75–85°C under aseptic conditions.

Continue stirring and cooling to 30–35°C before discharging the product. Under Class A laminar flow protection, perform aseptic filling, screw-capping, or heat-sealing; during the filling process, fill volume variations must be controlled, and leak testing must be conducted on a per-unit basis.The finished product may only be released after passing microbial limit tests (total aerobic bacteria, total mold and yeast, and control bacteria testing). Strict control of the aforementioned process steps is essential to ensure sterility, active ingredient retention, and emulsion stability during the transformation of the formulation from raw materials to the finished ointment.