Modeling of liposomal nano-carriers with dihydroquercetin, their characterisation and photoprotective properties evaluation

[...]. The aim of the study. To design nano structured liposomal systems for dihydroquercetin delivery into the skin and evaluate their protective effects from UV rays damage using biological methods. The objectives of the study: 1. To evaluate the properties of dihydroquercetin for protecting cell cultures from UV irradiation in vitro. 2. To investigate and select plant based materials for skin penetration enhancement of dihydroquercetin. 3. To design lipid nano-carriers systems with dihydroquercetin containing selected skin penetration enhancers, perform optimisation and evaluate their quality. 4. To perform biopharmaceutical characterization of experimental formulations and evaluate their skin penetration into human skin ex vivo. 5. To evaluate the properties of experimental formulations for protecting cell cultures from UV irradiation in vitro. [...]

Formulation and Biopharmaceutical Evaluation of Lipid Nanoparticle Formulation Containing Dexpanthenol

Dexpanthenol (DXP) is an alcoholic analogue of pantothenic acid with reported ant-inflammatory and regenerative properties. Topical DXP acts like a moisturizer, improving stratum corneum hydration, reducing trans epidermal water loss and maintaining skin softness and elasticity. However, DXP lacks the ability to penetrate into deeper layers of the skin, which reduces its potential applications. Studies over the last decades showed possible application of lipid vesicles as a tool to improve drug topical delivery. The aim of this study was to prepare an optimized lipid nanoparticle formulation (LNF) containing 1 % of DXP for dermal delivery. Soy phosphatidylcholine (PC) (>95 % purity, Lipoid GmbH, Switzerland), cholesterol (CHOL) (Sigma Aldrich, Germany), Tween 80 (T) (Sigma Aldrich, Germany) and deionized water were selected as main components forming the LNF. Optimization plan was prepared using experimental design software Design Expert® 7 (Stat-Ease). It was based on LNFs responses of particle size, polydispersity index (PDI), ζ-potential, pH, entrapment efficiency (EE) and in vitro release. The optimization factor was the amount of PC, while the selected amounts of CHOL and T were 3 % and 8 % of PC mass, respectively. The preparation procedure of LNs was the following: the components were stirred for 2 hours and left for “swelling of lipids” overnight followed by direct sonication as homogenization method. The LNs were analyzed 24 hours after preparation. The response optimization of experiments was the liposome formulation containing 797,0 mg of PC per 10 mL of preparation. The experimental results of characterization of optimal liposome formulation were in good agreement with those predicted by the optimization software. The characteristics of obtained optimal formulation were: particle size 62,75± 0.97nm, polydispersity index was 0,224±0.006, pH 7,2±0.08, EE 51.41 ± 5.09%. ζ-potential observed with lipid preparations showed that the negativ

Skin Penetration Enhancement by Natural Oils for Dihydroquercetin Delivery

Natural oils are commonly used in topical pharmaceutical formulations as emulsifiers, stabilizers or solubility enhancers. They are presented as safe and inert components, mainly used for formulation purposes. It is confirmed that natural oils can affect the skin penetration of various substances. Fatty acids are mainly responsible for this effect. Current understanding lacks reliable scientific data on penetration of natural oils into the skin and their skin penetration enhancement potential. In the current study, fatty acid content analysis was used to determine the principal fatty acids in soybean, olive, avocado, sea-buckthorn pulp, raspberry seed and coconut oils. Time of flight secondary ion mass spectrometry bioimaging was used to determine the distribution of these fatty acids in human skin ex vivo after application of the oils. Skin penetration enhancement ratios were determined for a perspective antioxidant compound dihydroquercetin. The results demonstrated skin penetration of fatty acids from all oils tested. Only soybean and olive oils significantly increased the skin distribution of dihydroquercetin and can be used as skin penetration enhancers. However, no correlation can be determined between the fatty acids’ composition and skin penetration enhancement using currently available methodological approaches. This indicates that potential chemical penetration enhancement should be evaluated during formulation of topically applied products containing natural oils