Testing of resveratrol microemulsion photostability and protective effect against UV induced oxidative stress

Resveratrol is well known for its antioxidant activity and susceptibility to ultraviolet radiation. Development of formulations providing improved stability and relevant drug delivery of resveratrol is still a challenging task. The aim of this study was to determine protective characteristics of formulated microemulsions by evaluating photoisomerization of resveratrol and to investigate the effects of resveratrol on human keratinocyte cells under oxidative stress caused by ultraviolet radiation. Incorporation of resveratrol into microemulsions resulted in increased photostability of active compounds and the results demonstrated that photodegradation of resveratrol was significantly delayed. Results of biopharmaceutical evaluation in vitro demonstrated that up to 60 % of resveratrol was released from microemulsions within 6 hours under a constant release rate profile. In vivo biological testing confirmed the ability of resveratrol to protect cells from oxidative stress and to increase cell viability. It was concluded that microemulsions might be considered in the development of UV light sensitive compounds

Release of rosmarinic acid from semisolid formulations, and its penetration through the human skin ex vivo

The aim of this study was to evaluate the release of rosmarinic acid (RA) from the experimental topical formulations with the Melissa officinalis L. extract and to evaluate its penetration through undamaged human skin ex vivo. The results of the in vitro release study showed that higher amounts of RA were released from the emulsion vehicle when lemon balm extract was added in its dry form. An inverse correlation was detected between the released amount of RA and the consistency index of the formulation. Different penetration of RA into the skin may be influenced by the characteristics of the vehicle as well as by the form of the extract. The results of penetration assessment showed that the intensity of RA penetration was influenced by its lipophilic properties: RA was accumulating in the epidermis, while the dermis served as a barrier, impeding its deeper penetration

Assessment of Lemon Balm ( Melissa officinalis

The aim of the study was to design gels with lemon balm extract, assess their quality, and investigate the effect of rosmarinic acid on skin cells in normal conditions and under oxidative stress. Methods. The quantities of rosmarinic acid (RA) released from gels were evaluated by applying the HPLC technique. HaCaT cell viability was assessed by using the MTT method. ROS generation was measured using DCFH-DA dye. The results showed that the gelling material affected the release of RA content from gels. Lower and slower RA content release was determined in carbomer-based gels. After 6 hours of biopharmaceutical research in vitro, at least 4% of RA was released from the gel. The results of the biological studies on HaCaT cells demonstrated that, in the oxidative stress conditions, RA reduced intracellular ROS amounts to 28%; 0.25–0.5 mg/mL of RA increased cell viability by 10–24% and protected cells from the damage caused by H2O2. Conclusions. According to research results, it is appropriate to use a carbomer as the main gelling material, and its concentration should not exceed 1.0%. RA, depending on the concentration, reduces the amount of intracellular ROS and enhances cell viability in human keratinocytes in oxidative stress conditions

Examination of rheological and physicochemical characteristics in Lithuanian honey

The aim of the study was to determine the effect of the biological origin and temperature on rheological and physicochemical characteristics of honey. The honey of the selected varieties differed in color, scent, microstructure, total acidity, moisture, and pH. The level of moisture statistically significantly correlated with the rheological characteristics. The highest total acidity was a characteristic of forest and buckwheat honey, and the lowest of acacia honey. The lowest pH value (3.76) was found in forest and rape honey, and the highest in eucalyptus honey. Moisture levels significantly correlated with the rheological characteristics. All varieties of honey at all the studied temperatures were characterized by properties of non-Newtonian substances. The study showed that the effect of temperature on rheological characteristics of different types of honey varied and was more pronounced in honey with a crystalline structure, and less pronounced in non-crystalline honey.Key words: Honey, rheological characteristics, physicochemical properties

Design and Formulation of Optimized Microemulsions for Dermal Delivery of Resveratrol

The objective of this study was to formulate optimal formulations of microemulsions (MEs) and evaluate their feasibility for delivery of resveratrol into human skin ex vivo. Oil-in-water MEs were formulated using surfactant (S) PEG-8 caprylic/capric glycerides and cosurfactant (CoS) polyglyceryl-6-isostearate. Ethyl oleate was used as an oily phase. MEs were formulated using 5 : 1, 6 : 1, and 7 : 1 surfactant and cosurfactant (S : CoS) weight ratios. Pseudoternary phase diagrams were constructed and optimal compositions of MEs were obtained using Design Expert software. Mean droplet size for optimized ME formulations was determined to be 68.54 ± 1.18 nm, 66.08 ± 0.16 nm, and 66.66 ± 0.56 nm for systems with S : CoS weight ratios 5 : 1, 6 : 1, and 7 : 1, respectively. Resveratrol loading resulted in mean droplet size increase. The distribution of droplet size between fractions changed during storage of formulated MEs. Results demonstrated the increase of number of droplets and relative surface area when S : CoS weight ratios were 6 : 1 and 7 : 1 and the decrease when S : CoS weight ratio was 5 : 1. The highest penetration of resveratrol into the skin ex vivo was determined from ME with S : CoS weight ratio 5 : 1. It was demonstrated that all MEs were similar in their ability to deliver resveratrol into the skin ex vivo

Propolio ekstrakto komponentų atsipalaidavimo iš emulsinių dispersijų tyrimai

Tyrimo tikslas. Pagrindo sukūrimas yra vienas pagrindinių uždavinių kuriant pusiau kietąją vaisto formą, skirtą išoriniam vartojimui. Pusiau kietojo preparato stabilumą saugojimo metu galima prognozuoti remiantis klampos tyrimais. Tinkama pusiau kietojo preparato pagrindo sudėtis lemia jo stabilumą ir reikiamą vaistinės medžiagos atsipalaidavimo kinetiką. Įvertinant kremų technologiją, ypač kompleksinių vaistinių medžiagų (pvz., skystųjų, tirštųjų, sausųjų ekstraktų) įterpimo į pagrindą sudėtingumą, aktualios išlieka kremų pagrindų sudėties paieškos, norint išvengti ilgai trunkančių šildymo bei lydymo procesų. Tirštasis propolio ekstraktas, pasižymintis antimikrobiniu, antivirusiniu, priešuždegiminiu bei antioksidaciniu poveikiu, buvo pasirinktas kaip kompleksinė biologiškai veiklioji medžiaga kuriamos emulsinės dispersinės sistemos tyrimams. Tyrimų tikslas buvo nustatyti fizikinių ir cheminių savybių bei veikliųjų medžiagų išsiskyrimo greičio iš modeliuojamos vaisto formos in vitro rodiklio tarpusavio priklausomybę ir, remiantis tuo, pagrįsti emulsinio (vanduo-aliejus) kremo sudėties ir technologijos priimtinumą. Tyrimo medžiaga ir metodai. Propolio tirštasis ekstraktas (1–3 proc. nuo bendrosios sistemos masės) buvo įterptas į emulsinę sistemą vanduo-aliejus. Modelinių emulsinių sistemų kokybė įvertinta pagal jų klampą, polifenolinių junginių kiekį bei jų išsiskyrimo iš pagrindo greitį pritaikius in vitro modelį. Polifenolinių junginių kiekis μg/ml apskaičiuotas pritaikius ferulo rūgšties standartinę kalibracinę kreivę, naudojant spektrofotometrinį metodą. Rezultatai. Tyrimų duomenimis, tinkama emulsiklio koncentracija, būtina modeliuoti homogenišką, stabilią pusiau kietąją emulsinę sistemą su propolio tirštuoju ekstraktu, yra nuo 3 iki 12 proc. Klampos tyrimai parodė, kad emulsiklio kiekis modeliuojamose pusiau kietosiose sistemose turi įtakos jų klampai ir beveik nekeičia polifenolinių junginių išsiskyrimo iš kremo matricos greičio. Tyrimais nustatyta, kad tirštasis propolio ekstraktas emulsinėse sistemose klampos pokyčiui turi mažiau įtakos nei kremo temperatūra. Išvada. Patvirtinta, kad klampos pokytis emulsinėse dispersinėse sistemose, didėjant temperatūrai, neturėjo įtakos modelinių dispersinių sistemų stabilumui, o tai būtina įvertinti nustatant modeliuojamų preparatų laikymo sąlygas jų saugojimo metu

Release of Propolis Phenolic Acids from Semisolid Formulations and Their Penetration into the Human Skin In Vitro

Antioxidant and free radical scavenging effects are attributed to phenolic compounds present in propolis, and when delivered to the skin surface and following penetration into epidermis and dermis, they can contribute to skin protection from damaging action of free radicals that are formed under UV and premature skin aging. This study was designed to determine the penetration of phenolic acids and vanillin into the human skin in vitro from experimentally designed vehicles. Results of the study demonstrated the ability of propolis phenolic acids (vanillic, coumaric, caffeic, and ferulic acids) and vanillin to penetrate into skin epidermis and dermis. The rate of penetration and distribution is affected both by physicochemical characteristics of active substances and physical structure and chemical composition of semisolid vehicle. Vanillin and vanillic acid demonstrated relatively high penetration through epidermis into dermis where these compounds were concentrated, coumaric and ferulic acids were uniformly distributed between epidermis and dermis, and caffeic acid slowly penetrated into epidermis and was not determined in dermis. Further studies are deemed relevant for the development of semisolid topically applied systems designed for efficient delivery of propolis antioxidants into the skin

Biopharmaceutical Evaluation of Capsules with Lyophilized Apple Powder

Apples are an important source of biologically active compounds. Consequently, we decided to model hard gelatin capsules with lyophilized apple powder by using different excipients and to evaluate the release kinetics of phenolic compounds. The apple slices of “Ligol” cultivar were immediately frozen in a freezer (at −35°C) with air circulation and were lyophilized with a sublimator at the pressure of 0.01 mbar (condenser temperature, −85°C). Lyophilized apple powder was used as an active substance filled into hard gelatin capsules. We conducted capsule disintegration and dissolution tests to evaluate the quality of apple lyophilizate-containing capsules of different encapsulating content. Individual phenolic compounds can be arranged in the following descending order according to the amount released from the capsules of different compositions: chlorogenic acid > rutin > avicularin > hyperoside > phloridzin > quercitrin > (−)-epicatechin > isoquercitrin. Chlorogenic acid was the compound that was released in the highest amounts from capsules of different encapsulating content: its released amounts ranged from 68.4 to 640.3 μg/mL. According to the obtained data, when hypromellose content ranged from 29% to 41% of the capsule mass, the capsules disintegrated within less than 30 min, and such amounts of hypromellose did not prolong the release of phenolic compounds. Based on the results of the dissolution test, the capsules can be classified as fast-dissolving preparations, as more than 85% of the active substances were released within 30 min

Quality analysis of semisolid formulations with the liquid extract of elderflower (Sambucus Nigra L.)

The active ingredients in the Elderflower liquid extract are responsible for the antibacterial, antioxidant and anti-inflammatory effects of the plant. The aim of the study was to design semisolid formulations with liquid Elderflower extract and evaluate the quality of them using a biopharmaceutical research method in vitro. The quality of the Elderflower (Sambucus nigra L.) extracts were evaluated spectrophotometrically by determining the total polyphenols and flavonoids content. Antiradical activity was determined by employing the spectrophotometrically DPPH free radical scavening method. Antibacterial activity was determined in vitro using the agar diffusion method. The biopharmaceutical experiment in vitro of the semisolid pharmaceutical formulations was performed by using modified Franz type diffusion cells. The results revealed that the highest amount of active compounds were found in the extracts when 70% (v/v) ethanol was used for the extraction of the raw material. The extracts obtained have antiradical activity and antimicrobial effects against S. aureus and B. cereus. Released amount of active compounds decreased when oleogel concentration in the formulation increased. The in vitro results of a biopharmaceutical semisolid formulation study showed that the base and the amount of excipients affected the release kinetics of the active compounds from the formulations. The results of the study showed that, as the lipophilicity and viscosity of the base increase, the formulation is characterized by a prolonged action: the release of the flavonoids, with the increase in the amount of oleogel, slow down. The best carrier of ederflower liquid extract was confirmed the hydrophilic base