Topical administration of phenylethyl resorcinol (PR) has attracted much attention as skin lightening agent with potent anti-tyrosinase activity. Two novel types of elastic carriers were developed to overcome the limitation of PR as topical delivery by increasing the solubility, stability and decreasing skin irritation compared to conventional liposomes. In addition, it also promotes skin penetration of PR to reach deep skin layer at the target site. The lead formulations were obtained from the invasomes containing 1% (w/v) d-limonene mixed with 10% (v/v) absolute ethanol as the skin enhancer, and transfersomes containing 15% (w/w) sodium deoxycholate (SDC) as edge activator. All formulations gave a vesicle size < 500 nm, polydispersity index (PDI) < 0.3, high zeta potential, entrapment efficiency > 50%, and good stability on storage at 30 °C at 75% RH for 4 months. Transfersomes have a lower degree of deformability (6.63%) than invasomes (25.26%). In contrast, the liposomes as rigid vesicles do not show a deformable property. This characteristic affects the skin permeation, and thus, transfersomes with high elastic property provided a significantly higher cumulative amount, steady state flux (J ss) and permeability coefficient (Kp ) compared to other formulations. However, in vitro PR accumulation in full-thickness newborn pig skin demonstrated that the application of elastic carrier formulations gave significantly higher accumulation than liposomes, and gave anti-tyrosinase activity up to 80%. These results are straightforwardly related to the results of cellular level study. Transfersomes and invasomes showed higher tyrosinase inhibition activity and melanin content reduction when compared to liposomes in B16 melanoma cells. In addition, acute irritation test in rabbits confirmed that these formulations are safe for skin application. Therefore, elastic vesicle carriers have the efficiency to deliver PR into the deep skin in both quantity and effectiveness which are better than conventional liposomes and appropriate for a skin lightening product.

Ethosome formulations containing phenylethyl resorcinol (PR) were developed. The formulation was produced from 0.5% w/v PR, 0.5% w/v cholesterol from lanolin, 3% w/v L-α-phosphatidylcholine from soybean, 30% v/v absolute ethanol, and water up to 100% v/v. It was characterized by a vesicular size of 389 nm, low polydispersity index of 0.266, zeta potential of −34.19±0.44 mV, high PR entrapment efficiency of 71%, and good stability on storage at 4 and 30°C at 75% RH for 4 months. In vitro studies using pig skin revealed that permeation coefficient of PR from ethosomes was significantly higher than that from liposomes. In vitro retention profiles showed that PR accumulation in pig skin following application of ethosome formulations was 7.4-, 3.3-, and 1.8-fold higher than that achieved using liposomes, 20% propylene glycol solution, and 30% hydroethanolic solution, respectively. An inhibition value of around 80% was measured for antityrosinase activity of PR in pig skin. Consistently, ethosomes exhibited higher tyrosinase inhibition activity and melanin content reduction when compared to other formulations in B16 melanoma cells. Ethosomes did not cause acute dermal irritation in albino rabbits. These findings demonstrate that ethosomes are capable of delivering PR into the skin efficiently and hold promise for topical application of skin lightening products.

Rhodomyrtone, a plant-derived principal compound isolated from Rhodomyrtus tomentosa (Myrtaceae) leaf extract, was assessed as a potential natural alternative for the treatment of acne vulgaris. The clinical efficacy of a 1% liposomal encapsulated rhodomyrtone serum was compared with a marketed 1% clindamycin gel. In a randomized and double-blind controlled clinical trial, 60 volunteers with mild to moderate acne severity were assigned to two groups: rhodomyrtone serum and clindamycin gel. The volunteers were instructed to apply the samples to acne lesions on their faces twice daily. A significant reduction in the total numbers of acne lesions was demonstrated in both treatment groups between week 2 and 8 (p < 0.05). Significant differences in acne numbers compared with the baseline were evidenced at week 2 onwards (p < 0.05). At the end of the clinical trial, the total inflamed acne counts in the 1% rhodomyrtone serum group were significantly reduced by 36.36%, comparable to 34.70% in the clindamycin-treated group (p < 0.05). Furthermore, a commercial prototype was developed, and a clinical assessment of 45 volunteers was performed. After application of the commercial prototype for 1 week, 68.89% and 28.89% of volunteers demonstrated complete and improved inflammatory acne, respectively. All of the subjects presented no signs of irritation or side effects during the treatment. Most of the volunteers (71.11%) indicated that they were very satisfied. Rhodomyrtone serum was demonstrated to be effective and safe for the treatment of inflammatory acne lesions.

• Key part is utilizing the 3D-printed rotor in hydrodynamic cavitation reactor. • Continuous nanoemulsion formulation was studied using HCR. • Smallest droplet size of 366.4 nm can be created by HCR. • Mechanical stirrer, ultrasound, hydrodynamic cavitation were compared. • Nanoemulsion from HCR reactor gave the highest cumulative release of niacin.

Fish collagen is a good source of protein and essential amino acids. It has a wide range of applications in food manufacturing, pharmaceutics, cosmetics, etc. By-products obtained from fish processing industries are currently used as alternative sources for the production of collagen and gelatin. Hydrolyzed collagen derived from fish skin has properties that are beneficial in cosmetic products. The aim of this study was to: (1) formulate a cosmetic product containing hydrolyzed fish collagen obtained from a by-product of fish processing industries, and other effective ingredients such as vitamin C, vitamin E and vitamin B3, (2) evaluate the physicochemical properties and stability of the product, and (3) conduct a facial skin evaluation test wherein volunteers use the product and have their facial skin analyzed. The formulated serum was translucent with low turbidity and had a pH of 7.7, and a viscosity of 1333 cps. The stability of the formulation was good, without any significant change in appearance, pH and viscosity as tested by freeze–thaw cycle testing, and after storage at room temperature for a period of 6 months. Furthermore, the results from the Visia skin analysis instrument revealed that the product was able to enhance facial skin moisture, reduce skin pores and wrinkles, and brighten the skin significantly when regularly used for at least 2 weeks. In conclusion, it was observed that hydrolyzed fish collagen obtained from a by-product of fish processing industries could be a sustainable and suitable material utilized in the production of safe and useful cosmeceutical products.

Phenylethyl Resorcinol (PR) is a cosmeceutical skin lightening agent and the purpose of this study was to enhance its stability by using liposomal cream formulation which increases local efficacy and safety. Liposome formulation was prepared by modified ethanol injection method, and it contained soy phosphatidyl choline (SPC), cholesterol (CHO), Tween 80 (TW80) and deoxycholic acid (DA) mixed with 2% PR. The physicochemical properties, skin permeation as well as cellular study were evaluated in order to obtain the optimized formulation. The optimized liposome formulation composed of SPC:TW80:DA (84:16:2.5) and exhibited vesicle size, polydispersity index (PDI) and zeta potential of 286.4 +/- 8.04 nm, 0.317 +/- 0.03 and -39.20 +/- 3.85 mV, respectively. Entrapment efficiency (EE) of liposome formulation was 93.55 +/- 0.05%. The vesicle was spherical in shape and showed good physicochemical stability for 4 months. The skin permeation study demonstrated that liposome with a negative charge could result in a high PR skin deposition value of 1732.76 +/- 216.24 mu g/cm(2) after 24 h. Cellular study showed that liposome formulation could inhibit melanin content in B16 melanoma cells and enhance cell viability in HaCaT keratinocyte cells. The optimized PR liposome was incorporated in cream and investigated physicochemical properties, stability and skin permeation. Liposomal PR cream showed a good stability and a superior result than PR cream in skin permeation parameters, as well as in tyrosinase inhibition.