Hydrogels are the three-dimensional network structures obtained from a class of synthetic or natural polymers which can absorb and retain a significant amount of water. Hydrogels are one of the most studied classes of polymer-based controlled drug release. These have attracted considerable attention in biochemical and biomedical fields because of their characteristics, such as swelling in aqueous medium, biocompatibility, pH and temperature sensitivity or sensitivity towards other stimuli, which can be utilized for their controlled zero-order release. The hydrogels are expected to explore new generation of self-regulated delivery system having a wide array of desirable properties. This review highlights the exciting opportunities and challenges in the area of hydrogels. Here, we review different literatures on stimuli-sensitive hydrogels, such as role of temperature, electric potential, pH and ionic strength to control the release of drug from hydrogels.

https://www.tandfonline.com/doi/pdf/10.3109/10717544.2014.940091

Stimuli-responsive hydrogels in drug delivery and tissue engineering

Biologically synthesised silver nanoparticles from three diverse family of plant extracts and their anticancer activity against epidermoid A431 carcinoma.

The European Medicines Agency (EMA) and the Current Good Manufacturing Practices (cGMP) in the United States of America, define excipient as the constituents of the pharmaceutical form other than the active ingredient, i.e., any component that is intended to furnish pharmacological activity. Although dendrimers do not have a pharmacopoeia monograph and, therefore, cannot be recognized as a pharmaceutical excipient, these nanostructures have received enormous attention from researchers. Due to their unique properties, like the nanoscale uniform size, a high degree of branching, polyvalency, aqueous solubility, internal cavities, and biocompatibility, dendrimers are ideal as active excipients, enhancing the solubility of poorly water-soluble drugs. The fact that the dendrimer's properties are controllable during their synthesis render them promising agents for drug-delivery applications in several pharmaceutical formulations. Additionally, dendrimers can be used for reducing the drug toxicity and for the enhancement of the drug efficacy. This review aims to discuss the properties that turn dendrimers into pharmaceutical excipients and their potential applications in the pharmaceutical and biomedical fields.

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Dendrimers as Pharmaceutical Excipients: Synthesis, Properties, Toxicity and Biomedical Applications.

Nowadays, many consumers prefer foods with a high content of nutraceuticals that contribute to the prevention or healing of chronic diseases. Therefore, in recent years, more and more researchers have studied the bioefficiency, safety, and toxicity of nutraceutical-enriched foods. The key stage of nutraceutical bioefficiency is oral bioavailability, which involves the following processes: the release of nutraceuticals from food matrices or nanocarriers in gastrointestinal fluids, the solubilization of nutraceuticals and their interaction with other components of gastrointestinal fluids, the absorption of nutraceuticals by the epithelial layer, and the chemical and biochemical transformations into epithelial cells. These processes are endogenous factors that greatly influence the bioavailability of nutraceuticals. In addition to endogenous factors, the bioavailability of nutraceuticals is also affected by exogenous factors, such as: physicochemical properties of nutraceuticals, food matrix, food processing and storage, and so forth. Both the endogenous and exogenous factors are comprehensively analyzed in this review. Thus, the physicochemical and enzymatic processes involved in food digestion are described, highlighting the role of each stage of gastrointestinal tract (mouth, stomach, and intestine) in nutraceuticals bioaccessibility. The structure and functions of the mucus and epithelial layers, the mechanisms involved in the active and passive transport of nutraceuticals through the cell membrane, and phase I and phase II metabolism reactions are also discussed. Finally, this review focuses on several types of bioactive-loaded nanocarriers such as lipid-based, surfactant-based, and biopolymeric nanocarriers that improve the bioavailability of nutraceuticals.

https://onlinelibrary.wiley.com/doi/epdf/10.1111/1541-4337.12547

Bioavailability of nutraceuticals: Role of the food matrix, processing conditions, the gastrointestinal tract, and nanodelivery systems

Objective To perform phytochemical screening, estimate total phenolics, flavonoids and to evaluate antioxidant potential of Moringa peregrina (M. peregrina) leaves. Methods The dried powdered leaves of M. peregrina (150 g) were extracted exhaustively by Soxhlet with ethanol and then fractionated into hexane, chloroform, ethy alacetate and methanol. All the prepared extracts were also analyzed by gas chromatography-mass spectrometry to identify and characterize the chemical compounds present in the crude extracts. Folin- Ciocalteu reagent and aluminium chloride colorimetric methods were used to estimate total phenolic and flavonoid content of extracts. Hydrogen peroxide and 1,1 diphenyl -2-picrylhydrazyl were used to determine in vitro antioxidant activity. Results Phytochemical analysis of ethanol extract showed presence of major classes of phytochemicals. Gas chromatography-mass spectrometry results revealed presence of 19 phytoconstituents in hexane extract, 6 in ethyl acetate and 7 compounds in methanolic extract. Methanol extract was found to contain the highest phenolic content and flavonoids. In vitro antioxidant activities of all crude extracts were significant and comparable with the standard ascorbic acid. Conclusions Results of this study show that the leaves of M. peregrina are the rich source of phenolic compounds that can play an important role in preventing the progression of many diseases.

GC-MS analysis, determination of total phenolics, flavonoid content and free radical scavenging activities of various crude extracts of Moringa peregrina (Forssk.) Fiori leaves

This document is aimed to describing the potential benefits of the Moringa tree as a nutrient. Moringa tree can be utilized in treating the malnutrition in a local and cost-effective manner. Malnutrition causes a great deal of human suffering and is associated with more than half of all deaths of children worldwide. Malnutrition severely affects the socio-economic development of a nation because a work force that is stunted both mentally and physically may have a reduced work capacity. Thus nutrition plays an important role in the reproduction of poverty from one generation to the next. Not only is the Moringa oleifera tree extraordinary in that all parts of the tree are edible, but the most amazing aspect of the tree is its exceptionally high nutritional value. The leaves of the Moringa tree are an excellent source of vitamin A, vitamin B vitamin C and other minerals. The leaves are also an outstanding source of calcium, protein, potassium and iron. The content of amino acids such as methionine and cystine is also high. Carbohydrates, fats and phosphorous content are low making this one of the finest plant foods to be found. Present review focuses on the potential benefits of Moringa oleifera in treatment of malnutrition.

Moringa : The herbal gold to combat malnutrition

Purpose of writing this review on microspheres was to compile the recent literature with special focus on formulation variables which affect the drug entrapment efficiency of microspheres. There are various approaches in delivering a therapeutic substance to the target site in a controlled release fashion. One such approach is using microspheres as carriers for drugs.Â  Microencapsulation is used to modify and delayed drug release form pharmaceutical dosage forms. For success of microspheres as drug delivery system its necessary to obtained desired particle size, maximum drug entrapment, mucoadhesion, swelling index and drug release. This can be obtained by optimizing the formulation as well as process variables but before designing the microspheres formulation deep understanding the effect of various variables on characteristics of microspheres is necessary. The intent of the paper is to highlight the reported study on various formulation variables those are might be useful to encountered several problems which is reason for low drug entrapment efficiency

From formulation variables to drug entrapment efficiency of microspheres: a technical review

This review gives concise information about the dendrimers, properties, synthesis and application in drug delivery, diagnosis and therapy. Due to their unique architecture these have improved physical and chemical properties. They show high solubility, miscibility and reactivity due to their terminal groups. Dendrimers have well defined size, shape, molecular weight and monodispersity. These properties make the dendrimers a suitable carrier in drug delivery application. Dendrimers are unimolecular miceller in nature and due to this enhances the solubility of poorly soluble drugs. Their compatibility with DNA, heparin and polyanions make them more versatile. Dendrimers, also referred as modern day polymers, they offer much more good properties than the conventional polymers. Due to their multivalent and mono disperse character dendrimers have stimulated wide interest in the field of chemistry biology, especially in applications like drug delivery, gene therapy and chemotherapy. Self assembly produces a faster means of generating nanoscopic functional and structural systems. But their actual utility in drug delivery can be assessed only after deep understanding of factors affecting their properties and their behavior in vivo. Key words : Dendrimers, PAMAM, monodispersity, Divergent-Convergent synthesis, carrier for drug delivery

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Dendrimers in drug delivery, diagnosis and therapy: basics and potential applications

This review gives concise information about the application of dendrimers in the field of drug delivery. Due to their unique architecture these have improved physical and chemical properties. Due to their terminal groups these show high solubility, miscibility and reactivity. Dendrimers have well defined size, shape, molecular weight and monodispersity. These properties make the dendrimers a suitable carrier in drug delivery application. Dendrimers are unimolecular miceller in nature and due to this enhances the solubility of poorly soluble drugs. Their compatibility with DNA, heparin and polyanions make them more versatile. Dendrimers, also referred as modern day polymers, they offer much more good properties than the conventional polymers. Due to their multivalent and mono disperse character dendrimers have stimulated wide interest in the field of chemistry biology, especially in applications like drug delivery, gene therapy and chemotherapy. Self assembly produces a faster means of generating nanoscopic functional and structural systems. But their actual utility in drug delivery can be assessed only after deep understanding of factors affecting their properties and their behavior in vivo . Key words: Dendrimers, Drug targeting, nanoscale carriers.

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Potential application of dendrimers in drug delivery: a concise review and update

The main objective of the present work was to develop transdermal delivery of stavudine, a hydrophobic drug used for the treatment of AIDS, from ethosomes. All the system were characterized for vesicle morphology, particle size and entrapment efficiency by Scanning Electron Microscopy , Transmission Electron Microscopy, Differential light scattering and centrifugation respectively. The effect of different formulation variable on skin permeation of stavudine was studied via synthetic semipermeable membrane or skin of new born mice by using diffusion cell. The selected system were incorporated into HPMC gel and evaluated for both drug permeation and mice skin deposition. 2 The optimized ethosomal formulation showed transdermal flux 25.01±0.34 ig/cm /hr across rat skin as compared to 2 2 2.98±0.21ig/cm /hr for plane drug solution, 4.28±0.54 ig/cm /hr for hydroethanolic solution and 9.7±0/21 2 ig/cm /hr for classical liposome. Finally it was concluded from the study that, ethosomes can increase the transdermal flux, prolong the release and present an attractive route for sustained delivery of stavudine.

Ram Chand Dhakar

Papers

Moringa : The herbal gold to combat malnutrition

From formulation variables to drug entrapment efficiency of microspheres: a technical review

Dendrimers in drug delivery, diagnosis and therapy: basics and potential applications

Potential application of dendrimers in drug delivery: a concise review and update

Formulation Development and Evaluation of Ethosome of Stavudine