Nanoemulsions as vehicles for topical administration of glycyrrhetic acid: characterization and in vitro and in vivo evaluation.

Nano-emulsions are innovative colloidal systems characterized by high kinetic stability, low viscosity, and optical transparency, which make them very attractive in many dermatological applications. Furthermore their small size seems to favor the topical administration of actives which scarcely cross the skin. In the light of these interesting features, the present study was aimed to the evaluation, in vitro and in vivo, of glycyrrhetic acid (GA) release through the skin from the nanoemulsion system. GA-loaded nanoemulsion (GA(N)) was prepared by phase inversion temperature (PIT) method, and was characterized in order to determine mean droplet size and its stability during a well-defined storage period. Further Cryo-TEM studies were performed to obtain information regarding nanoemulsion structure. The GA release pattern from nanoemulsion was evaluated in vitro, to determine its percutaneous absorption through excised human skin (stratum corneum and epidermis, SCE), and in vivo evaluating GA topical anti-inflammatory activity on healthy human volunteers by the UVB-induced erythema model. Nanoemulsions prepared by PIT method showed a mean droplet diameter of 210 nm that drastically changed during a storage of 5 weeks at room temperature. In vitro and in vivo evidence showed that the nanoemulsion system significantly increased the transdermal permeability of GA in comparison to a control O/W emulsion (GA(O/W)) containing the same amount of active compound

Design of solid lipid nanoparticles for caffeine topical administration

Solid lipid nanoparticles (SLN) are drug carriers possessing numerous features useful for topical application. A copious scientific literature outlined their ability as potential delivery systems for lipophilic drugs, while the entrapment of a hydrophilic drug inside the hydrophobic matrix of SLN is often difficult to obtain.To develop SLN intended for loading caffeine (SLN-CAF) and to evaluate the permeation profile of this substance through the skin once released from the lipid nanocarriers. Caffeine is an interesting compound showing anticancer and protective effects upon topical administration, although its penetration through the skin is compromised by its hydrophilicity.SLN-CAF were formulated by using a modification of the quasi-emulsion solvent diffusion technique (QESD) and characterized by PCS and DSC analyses. In vitro percutaneous absorption studies were effected using excised human skin membranes (i.e. Stratum Corneum Epidermis or SCE).SLN-CAF were in a nanometric range (182.6 ± 8.4 nm) and showed an interesting payload value (75% ± 1.1). DSC studies suggest the presence of a well-defined system and the successful drug incorporation. Furthermore, SLN-CAF generated a significantly faster permeation than a control formulation over 24 h of monitoring.SLN-CAF were characterized by valid dimensions and a good encapsulation efficiency, although the active to incorporate showed a hydrophilic character. This result confirms the suitability of the formulation strategy employed in the present work. Furthermore, the in vitro evidence outline the key role of lipid nanoparticles in enhancing caffeine permeation through the skin

Nanostructured lipid dispersions for topical administration of crocin, a potent antioxidant from saffron (Crocus sativus L.)

© 2016 Elsevier B.V.Crocin, a potent antioxidant obtained from saffron, shows anticancer activity in in vivo models. Unfortunately unfavorable physicochemical features compromise its use in topical therapy.The present study describes the preparation and characterization of nanostructured lipid dispersions as drug delivery systems for topical administration of crocin and the evaluation of antioxidant and antiproliferative effects of crocin once encapsulated into nanostructured lipid dispersions.Nanostructured lipid dispersions based on monoolein in mixture with sodium cholate and sodium caseinate have been characterized by cryo-TEM and PCS. Crocin permeation was evaluated in vitro by Franz cells, while the oxygen radical absorbance capacity assay was used to evaluate the antioxidant activity. Furthermore, the antiproliferative activity was tested in vitro by the MTT test using a human melanoma cell line.The emulsification of monoolein with sodium cholate and sodium caseinate led to dispersions of cubosomes, hexasomes, sponge systems and vesicles, depending on the employed emulsifiers. Permeation and shelf life studies demonstrated that nanostructured lipid dispersions enabled to control both rate of crocin diffusion through the skin and crocin degradation. The oxygen radical absorbance capacity assay pointed out an interesting and prolonged antioxidant activity of crocin while the MTT test showed an increase of crocin cytotoxic effect after incorporation in nanostructured lipid dispersions.This work has highlighted that nanostructured lipid dispersions can protect the labile molecule crocin from degradation, control its skin diffusion and prolong antioxidant activity, therefore suggesting the suitability of nanostructured lipid dispersions for crocin topical administration

Ethosomes and transethosomes for mangiferin transdermal delivery

Mangiferin is a natural glucosyl xanthone with antioxidant and anti-inflammatory activity, making it suitable for protection against cutaneous diseases. In this study ethosomes and transethosomes were designed as topical delivery systems for mangiferin. A preformulation study was conducted using different surfactants in association with phosphatidylcholine. Vesicle dimensional distribution was monitored by photon correlation spectroscopy, while antioxidant capacity and cytotoxicity were respectively assessed by free radical scavenging analysis and MTT on HaCaT keratinocytes. Selected nanosystems were further investigated by cryogenic transmission electron microscopy, while mangiferin entrapment capacity was evaluated by ultracentrifugation and HPLC. The diffusion kinetics of mangiferin from ethosomes and transethosomes evaluated by Franz cell was faster in the case of transethosomes. The suitability of mangiferin-containing nanovesicles in the treatment of skin disorders related to pollutants was investigated, evaluating, in vitro, the antioxidant and anti-inflammatory effect of ethosomes and transethosomes on human keratinocytes exposed to cigarette smoke as an oxidative and inflammatory challenger. The ability to induce an antioxidant response (HO-1) and anti-inflammatory status (IL-6 and NF-kB) was determined by RT-PCR and immunofluorescence. The data demonstrated the effectiveness of mangiferin loaded in nanosystems to protect cells from damage. Finally, to gain insight into the keratinocytes' uptake of ethosome and transethosome, transmission electron microscopy analyses were conducted, showing that both nanosystems were able to pass intact within the cells

Nanocarriers and Microcarriers for enhancing the UV protection of sunscreens: an overview

This review addresses a major question of importance to pharmaceutical scientists: how can novel drug delivery systems play a role in maximizing the UV protection of sunscreens? Since more and more people are being diagnosed with skin cancer each year than all other cancers combined, adequate sun protective measures are pivotal. In this context, the present review is to give an up-to-date overview on the different nanocarrier systems that have been explored so far for encapsulating different types of UV filters present on the market. The aim of these carrier systems is to prevent skin penetration and to enhance the photoprotective potential of sunscreen actives. For each supramolecular system, a brief description along with the studies, achievements and pitfalls, on the type of UV actives inside them, ranging from classical UV filters to new generation of UV actives is given. A brief over-view of UV filters encapsulated in microcarriers is also discussed

Editorial of Special Issue "Botanicals: innovative tools for pharmaceutical, cosmetic and nutraceutical"

FDA defined “botanicals” as products of plant materials, algae, macroscopic fungi, and their combinations and considered them as finished, labeled products containing vegetables as ingredients, that can be used as conventional foods, dietary supplements, drugs, cosmetics, or medical devices depending on its route of administration, formulation, safety and intended use [1, 2]. Today, the use of medicinal plant remains widespread, and a significant portion of the world's population utilizes herbal natural products and supplements as the primary mode of healthcare [3,4]. In the United States, for instance, nearly 20% of adults and 5% of children utilize botanical supplements to treat different diseases. The increase in adoption of herbal remedies may be ascribed to: a general preference of natural therapies and aversion for other interventions like surgery, allopathic medicines etc; inclination towards self-medication based upon experience; affordable cost of herbal medicines and ease of availability; side effects associated with conventional medicines (especially in cases of chronic problems) and growing promotion of herbal medicines [4]. Botanicals in medicine are usually recommended for disease prevention and to maintain good health, while rarely their use is suggested for acute and/or life-threatening problems. More recently, it is observed a growing use of herbal medicine when conventional medicine is ineffective or for pain palliation in case of long-standing problems like cancer, arthritis, etc. [5]. Also the cosmetic market has been influenced by botanicals. In particular, it has been observed a growing trend in incorporating antioxidants in sunscreens and skincare products to replenish the natural reservoirs in the skin [6]. This “new renaissance” of herbal product obliges us to employ them with a real scientific method. Researchers having access to innovative technologies can optimize the use of herbal ingredients in natural formulations, to give safety and efficacy to the formulation across a scientific view, validating the traditional use, with no previous scientific evidence. On these bases, this special issue is aimed to give an overview of the current state of botanicals research, in order to collect recent scientific data on the development of pharmaceutical products, cosmetics, and nutraceuticals. The attention is focused on the chemical composition, biological activities [7-11] and nutritional aspects of new herbal products and on the application of innovative technologies or formulative approaches to improve their stability and bioavailability [8-10, 12-15]. Readers will find information about new natural products endowed with healthy activities. Flaxseed oil, for instance, is a very important product characterized by anti-oxidant, anti- inflammatory and anti-dysmetabolic effects and has been evaluated for a potential application in different diseases [8]. Brassica vegetables also possess anti-oxidative properties and are associated with the risk reduction of chronic diseases including cardiovascular diseases and cancer. The focus of the present special issue is also on some indigenous underutilized wild edible plants, such as Pereskia aculeate, a natural diet supplement studied as “novel food” in virtue of its high nutritional value [10] and Momordica cochinchinensis, a super fruit, of the functional food industry [11]. Finally, our readers will find interesting examples of innovative delivery strategies to increase the bioavailability of natural active compounds from vegetable sources. Extensive discussion on this special issue about different nanocarriers for the delivery of natural products, functional foods, dietary supplements, and herbal medicinal products is also addressed

Further characterization of the histidine gene cluster of Streptomyces coelicolor A3(2): nucleotide sequence and transcriptional analysis of hisD.

We have further characterized the genomic region of Streptomyces coelicolor A3(2) that contains genes involved in the biosynthesis of histidine. A 2,357-base pair fragment contained in plasmid pSCH3328 that complemented hisD mutations has been sequenced. Computer analysis revealed an open reading frame that encodes a protein with significant homology to the Escharichia coli, Salmonella typhimurium and Mycobacterium smegmatis hisD product, Saccharomyces cerevisiae HIS4C, and Neurospora crassa his3 gene products. Two other contiguous open reading frames oriented divergently with respect to hisD did not show significant similarity with any of the his genes or to other sequences included in the gene bank. S1 nuclease mapping and primer extension experiments indicate that the transcription initiation site of the his-specific mRNA coincides with the GUG translation initiation codon of the hisD cistron

Cloning and characterization of histidine biosynthetic gene cluster of Streptomyces coelicolor A3(2).

No abstract available