Gislaine Ricci Leonardi

Structural characterization and in vivo evaluation of retinyl palmitate in non-ionic lamellar liquid crystalline system.

Carrier systems for lipophilic drugs, such as the liquid crystalline systems (LCS) have been extensively studied to improve effect and selectivity. Retinyl palmitate (RP) is widely used in pharmaceutical and cosmetics products to improve the skin elasticity. The aim of this study was the development, characterization and the in vivo effectiveness of RP in non-ionic LCS structures. LCS containing polyether functional siloxane as oil phase, silicon glycol copolymer as surfactant and water in the ratio 30:10:60, with and without RP were studied. The results of the polarized light microscopy, small-angle X-ray scattering and rheology analysis indicated the presence of typical LCS structures with lamellar arrangement. Regardless of the presence of RP, the rheological studies showed the pseudo plastic behavior of the systems. However, highest hysteresis area was verified when comparing the system in the presence and in the absence of RP. Stability study SAXS monitored, carried out up to 30 days in various storage temperature conditions (25±2 °C, 37±2 °C and 5±2 °C) demonstrated the great structural stability of the LCS systems. The in vivo effectiveness analysis suggests that the RP-loaded LCS provided a significant reduction of the orbicular wrinkles in human volunteers (P=0.048).

Desenvolvimento de sistemas líquido-cristalinos empregando silicone fluido de co-polímero glicol e poliéter funcional siloxano

For the construction of the phase diagrams, the method of the aqueous titration was used. There were prepared 5 ternary diagrams, varying the surfactant and the oil phase. The liquid-crystalline phases were identified by polarized light microscopy. The formulations prepared with silicon glycol copolymer, polyether functional siloxane (PFS) and water (S1) and with diisopropyl adipate, PFS and water (S4) presented liquid-crystalline phases with lamellar arrangement. Moreover, after 15 days in hot oven (37 oC), the formulations presented hexagonal arrangement, evidencing the influence of the temperature in the organization of the system.

Estudo da variação do pH da pele humana exposta à formulação cosmética acrescida ou não das vitaminas A, E ou de ceramida, por metodologia não invasiva

FUNDAMENTOS: Os cosmeticos hidratantes melhoram a pele, aproximando-a de suas condicoes ideais, pois aumentam a quantidade de agua no estrato corneo. As vitaminas A e E, bem como as ceramidas, sao substâncias ativas que vem sendo muito empregadas em hidratantes, os quais constituem uma das mais importantes classes de produtos cosmeticos e de higiene corporal. OBJETIVO: - O objetivo deste trabalho foi avaliar o efeito no pH cutâneo da pele humana de uma emulsao O/A (constituida de base auto-emulsionante nao ionica) acrescida, ou nao, de vitamina A palmitato ou vitamina E acetato ou ceramida III, por metodologia nao invasiva METODOS:O estudo foi realizado em 40 mulheres com idade entre 30 e 45 anos, empregando-se o equipamento Skin Phmeter PH 900 PC. As medidas foram efetuadas no antebraco das voluntarias nos tempos de sete e 30 dias apos auto-aplicacao diaria (duas vezes ao dia), dos produtos envolvidos no estudo RESULTADOS E CONCLUSAO: A presenca das vitaminas A ou E, ou da ceramida nao alterou de maneira significativa o pH da pele, o que mostra que as formulacoes estudadas sao adequadas para o uso cosmetico.BACKGROUND: Moisturizers are believed to improve the skins condition by increasing the water content of the stratum corneum. Vitamins A and E and ceramides have been widely used in cosmetic moisturizing products, and these are one of the most important cosmetic and body care products. OBJECTIVE: The aim of this research was to evaluate the effects on the pH of human skin of an O/W emulsion (non ionic self-emulsifying base) with and without vitamin A palmitate, or vitamin E acetate, or ceramide III, using a non-invasive method. METHOD: The investigations were carried out on a group of 40 healthy female test subjects aged between 30 and 45 years old, using the Skin pH meter PH 900 PC. The measurements were performed on the forearm of volunteers at 7 and 30 days after daily use (twice a day) of the products used in the study. RESULTS AND CONCLUSION: The presence of vitamins A or E or ceramide III did not change the pH of the skin, consequently the formulations studied are suitable for cosmetic usage.

Physicochemical Characterization and Rheological Behavior Evaluation of the Liquid Crystalline Mesophases Developed with Different Silicones

This article presented physicochemical characterization and rheological behavior evaluation of the liquid crystalline mesophases developed with different silicones. There were prepared 5 ternary systems, which were carried out the determination of the relative density, the electric conductivity and polarized light microscopy analysis, being selected two systems to promote the Preliminary Stability Tests. The results showed that System 1 obtained the major liquid crystal formation and a higher stability. The temperature influences in the systems stability and phases structure. In hot oven, observed oneself the mixture of lamellar and hexagonal phase, for both systems.

The effect of topical caffeine on the morphology of swine hypodermis as measured by ultrasound

Background  Cellulite or lipodystrophy involves the modification of the subcutaneous adipose tissue. A wide variety of topical products is available to combat cellulite, but these have difficulties in being absorbed through the skin. One option is the therapeutic use of the ultrasound to enhance the transdermic transport of these drugs.

Topical Application of Retinyl Palmitate-Loaded Nanotechnology-Based Drug Delivery Systems for the Treatment of Skin Aging

The objective of this study was to perform a structural characterization and evaluate the in vitro safety profile and in vitro antioxidant activity of liquid crystalline systems (LCS) with and without retinyl palmitate (RP). LCS containing polyether functional siloxane (PFS) as a surfactant, silicon glycol copolymer (SGC) as oil phase, and water in the ratios 30 : 25 : 45 and 40 : 50 : 10 with (OLSv = RP-loaded opaque liquid system and TLSv = RP-loaded transparent liquid system, respectively) and without (OLS and TLS, respectively) RP were studied. Samples were characterized using polarized light microscopy (PLM) and rheology analysis. In vitro safety profile was evaluated using red cell hemolysis and in vitro cytotoxicity assays. In vitro antioxidant activity was performed by the DPPH method. PLM analysis showed the presence of lamellar LCS just to TLS. Regardless of the presence of RP, the rheological studies showed the pseudoplastic behavior of the formulations. The results showed that the incorporation of RP in LCS improved the safety profile of the drug. In vitro antioxidant activity suggests that LCS presented a higher capacity to maintain the antioxidant activity of RP. PFS-based systems may be a promising platform for RP topical application for the treatment of skin aging.

Silicone/vegetable oil Janus emulsion: Topological stability versus interfacial tensions and relative oil volumes

Several aspects were studied of the formation and destabilization in bulk of silicone/vegetable oil, SO/VO, Janus emulsions, stabilized by Tween 80. In the formation of the emulsions, it was unexpectedly found that the dispersions tended to contain both single and flocculated drops irrespective of the emulsification intensity. Microscopy of the emulsions with no cover glass revealed flocculated drops of a large (200-500 μm) central SO drop with many small VO drops attached. Applying a cover glass did not significantly change the drop size; instead two-oil Janus drops of well-defined contact angle were found. The emulsions showed rapid creaming irrespective of the preparation method, but a few days storage did not significantly change the drop size in the creamed layer, nor was separation of the oils detected. The total interfacial free energy of the Janus drops at equilibrium was compared to the two relevant alternatives; engulfed and separate drops. The Janus drop free energies were found less for all volume ratios of the oils, when the surfactant concentrations in the aqueous phase was sufficient to prevent spreading of VO on SO. Changing the surfactant concentration to bring the interfacial tensions closer to the critical value for spreading gave declining interfacial free energy difference to that of engulfed drops.

Evaluation of the ultrasound influence in the cutaneous penetration of d-panthenol: test in vitro.

Background  d‐panthenol is a popular additive in cosmetic and pharmaceutical preparations. However, in order for this vitamin to provide skin benefits, it must penetrate the stratum corneum.

Minimum Evaporation Model of Dermatological Delivery Systems. Lamellar Liquid Crystal Formulations Containing Brazilian Nut (Bertholletia excelsa HBK) Vegetable Oil and Guarana Glycolic Extract

Formulations with lyotropic liquid crystals were prepared from a Brazilian nut vegetable oil, guarana extract and combination of sorbitan monooleate (Span 80) and sorbitan monolaurate ethoxylate EO 20 (Tween 20) in the ratio 1:3 (surfactant component) and their physical–chemical aspects and rheological properties were determined. Compositions with liquid crystals were found in the pseudoternary diagram in a surfactant range of 70–90% and polarized light microscopy, small-angle x-ray scattering (SAXS) showed them to be lamellar. The preparations were furthermore characterized rheologically by shear stress shear rate sweeps finding plastic and pseudoplastic behavior without thixotropy. Electric conductivity and pH measurements demonstrated a potential for future application as dermatological delivery system of the active compounds in the Bertholletia excelsa and Paullinia cupana.

Efeito do ultrassom e do dexapantenol na organização das fibras colágenas em lesão tegumentar

OBJECTIVE: To analyze the effect of ultrasound (US), dexpanthenol (d-P) and a combination of these treatments (US+d-P) on collagen fiber organization in tegumentary lesions in rats by birefringence analysis. METHODS: Wistar rats (50) were anesthetized (Thionembutal - Sodic = 50mg/Kg), 1cm2 of dorsal region skin was removed, and the animals were divided into five groups: control (C), gel (G), US (3 MHz, 0.1 W/cm2, 1 minute, continuous), d-P (10%) and US+d-P. After daily treatment for 7 and 14 days, 6µm thick sections of lesioned areas were stained in picrosirius and measurements of the collagen birefringent area (µm2) were obtained using polarized light microscopy (Zeiss Axiolab-ZEISS- Germany) with histological image analysis software (KS 400 2.0 - Kontrol Eletronics, Munique, Germany). The means were compared by ANOVA followed by the Tukey test (p<0.05). RESULTS: The US+d-P group showed a significantly greater (p<0.001) birefringent area (1586.43±162.14) than the other experimental groups: C (139.36±35.35), US (317.55±129.9) and d-P (192.41±3657) by the 7th day of treatment, indicating acceleration of the wound healing process. By the 14th day of treatment, the US+d-P, US and d-P groups presented greater birefringence than the control group, but did not differ from each other. CONCLUSION: The combination of treatments (US+d-P) accelerated collagen fiber synthesis and organization in the early stages of cutaneous repair.