Influence of mechanochemical activation on dissolving model corrosion films formed on ion-exchange resins using Trilon B

Inorganic deposits formed during operation and intermediate storage contain radionuclides, whose removal during the chemical decontamination of spent ion-exchange resins used in filters for special water purification at nuclear power plants has proved to be a challenge. In such deposits, radionuclides of the corrosion group (58.60Co, 54Mn, 51Cr) are typically located in the crystal lattice of poorly soluble iron oxides. The present work discusses the possibility of using mechanochemical activation in the decontamination of spent ion-exchange resins polluted with deposits of activated corrosion products from structural materials. Samples of natural and synthesised on the surface of the KU-2-8 cation exchanger in the presence of the 57Co label magnetites were used as model deposits. It was shown that an increase in the duration of mechanochemical activation leads to an increase in the dissolution rate of magnetite in model decontamination solutions based on еthylenediaminetetraacetic acid disodium salt (Trilon B) and nitric acid. It was shown that, when using Trilon B, magnetite dissolves more efficiently, which is explained by the interaction between the oxide surface and organic complexing agents. It can be assumed that solid-phase reactions occur during the mechanochemical activation of magnetite in the presence of dry reagents (Trilon B, oxalic, ascorbic and citric acids). Therefore, a poorly soluble shell formed on the oxide surface hinders the dissolution at a low magnetite/solution ratio. Unlike the reagent-free activation, for magnetite activated in the presence of oxalic acid, an increase in the solution/magnetite ratio promotes the dissolution of iron oxides. Using the example of a model cation exchanger, it was shown that the rate and efficiency of decontamination of spent ion-exchange resins polluted with deposits containing activated corrosion products increase significantly after mechanochemical activation in the presence of oxalic acid.

FORMULATION AND CHARACTERIZATION OF CYCLODEXTRIN BASED CURCUMIN LOADED NANOSPONGE

Objective: The aim of proposed work is to develop and screen cyclodextrin based Nanosponge loaded with poorly soluble anticancer drug and to optimize most suitable Nanosystem with increased solubility and dissolution rate. Methods: Cyclodextrinnanosponge (CDNS) was prepared using pyromelliticdianhydride as a crosslinker for beta cyclodextrin monomer. Cyclodextrinnanosponge and curcumin were taken in 1:1 w/w proportion. The resultant curcumin loaded nanosponges were dried at 50±0.5 °C for 24 h. Results: The absorbance maxima for Curcumin was seen at 424.0 nm and for cyclodextrin was seen at 290.0 nm, The average melting point of pure drug is 181 °C which is complies with Stander melting point of drug and the aspect ratio of the nanosponge was found 1.037. Zeta potential noticed for CUR-CD-NS were more negative contrasted with separate plain CUR (−20.1±1.57) demonstrating solidness of the nanodispersion. Curcumin release from CUR-CDNS was upgraded to very nearly 10 folds toward the finish of 8 hour. Treatment with a combination of CUR-CDNS at 1:1 and 1:3 ratios resulted in an IC50 value was found 14.98 μg/ml. Conclusion: In vitro cytotoxicity study and combination index analysis showed the synergistic effect of CUR-CDNS against MCF-7 cells. The present study reveals that the combination of curcumin results in higher cytotoxicity against breast cancer cells.

Improvement of in vitro antioxidant activity of kaempferol by encapsulation in copolymer micelles

Antioxidant capacity of poorly soluble natural antioxidant kaempferol, in particular free or loaded in two types of cationic micelles, was studied on non-enzyme induced lipid peroxidation (LPO) in vitro. The micelles were based on triblock copolymers - poly(2-(dimethylamino)ethyl methacrylate-b-poly(propylene oxide)-b-poly(2-(dimethylamino)ethyl methacrylate (PDMAEMA-PPO-PDMAEMA) and poly(2-(dimethylamino)ethyl methacrylate-b-poly(ε-caprolactone)-b-poly(2-(dimethylamino)ethyl methacrylate (PDMAEMA-PCL-PDMAEMA). The lipid peroxidation was induced by incubating of rat liver microsomes with iron sulphate and ascorbic acid (Fe2+/AA). The effect of free and micellar kaempferol (at concentrations 25, 50 and 75 μg/ml) was assessed after 20 min incubation time. In the non-enzyme lipid peroxidation model, the kaempferol-loaded micelles significantly decreased the formation of malondialdehyde (MDA). The effect of kaempferol loaded in PDMAEMA-PCL-PDMAEMA micelles was more pronounced, showing an improved antioxidant activity in the conditions of oxidative stress and lipid peroxidation in vitro.

Improved Oral Delivery of Drugs Using Nanoemulsion

Administration of drugs through the oral route is considered the simplest and most convenient way to offer greater patient compliance than other routes. Most active drugs discovered in the past and those being discovered in recent times are inadequate because of their inherent limitations in physicochemical properties such as low solubility and permeability, resulting in poor bioavailability, especially after oral administration in the form of tablet or capsule. Pharmaceutical nanoemulsion is the most promising, safer, and multimodal technique for delivering poorly soluble drugs and gaining more attention due to its characteristics such as higher solubilisation capacity, smaller size, surface charge, and site-specific drug targeting. This chapter focuses on the biological fate of nanoemulsion after oral administration and a few case studies related to the oral application of nanoemulsion in delivering poorly soluble drugs. In addition, the anatomy and physiology of the GI tract, components of nanoemulsion, and methods of preparation are addressed.

Incorporation of poorly soluble drug Cefixime inside the micellar core of conventional and gemini surfactants

This work reports the physicochemical behavior of antibiotic drug, cefixime (CEF) in presence of cetyl trimethyl ammonium bromide (CTAB), dodecyl trimethyl ammonium bromide (DTAB), dodecyl ethyl dimethyl ammonium bromide, (DDAB),...

A Brief Review on Hydrophobic Modifications of Glycol Chitosan into Amphiphilic Nanoparticles for Enhanced Drug Delivery

Glycol chitosan (GC) is the chitosan derivative that is capable of forming amphiphilic nanoparticles upon structure modifications at the reactive functional amine group on the polymer sugar backbone. Owing to the hydrophilic feature of GC and hydrophobic moieties that can be added to the GC structure, modifiable nanosystems were constructed to entrap poorly soluble drugs, mostly chemotherapeutic agents and several anti-inflammatory, anaesthetic, immunosuppressant, and antifungal drugs for more efficient delivery of the payload to the target site and improving the intended therapeutic effects. This review highlights the various hydrophobic molecules used in the chemical modification of GC to create amphiphilic nanoparticles for hydrophobic drug delivery, along with the summary of their physicochemical criteria and successful therapeutic enhancement achieved with the application of the drug-loaded amphiphiles. The biodegradable, GC-based nanoparticles particularly having the inner hydrophobic core and outer hydrophilic shell are an efficient system for drug entrapment, protection and targeting to improve the bioavailability and safety of the drug, in particular for cancer treatment purposes. The significant drug delivery enhancements achieved by these various hydrophobically-modified GC nanoparticles may provide the insights for their further use in nanomedicine.

A Short Review on Application of Liquisolid Technology

In this paper we have surveyed about formulation and evaluation of Liquisolid formulations and its work in antidiabetics . Mostly poorly water soluble drugs are in research category despite of less dissolution rate and poor bioavailability. Solubility is a vital parameter to develop new formulation as industries faced serious issue regarding the poor aqueous solubility of the drugs. Various methods for solubility enhancement include modifications of the drug, involvement of co-solvents, complexation, salt formation, size reduction. A propitious technique to solve major challenges like solubility, dissolution rate and their bioavailability. This technique can be defined as the conversion of poorly soluble liquid medications into non-adherent, dry, compressible and free flowing powder mixtures with help of excipients. Many anti-diabetic drugs are belonging to BCS Class-II facing challenges like solubility and bioavailability.

Polymeric Micelles: A Novel Approach towards Nano-Drug Delivery System

Nano delivery systems, polymeric micelles represent one of the most promising delivery platforms for therapeutic compounds. It has shown that a poorly soluble molecule which has high potency and remarkable toxicity can be encapsulated with the polymeric micelle. There are various poorly soluble drugs used in micellar preparations, mostly for their anti-cancer activity. Drugs in the inner core protect the drug from degradation and allow drug accumulation in the tumour site in the case of cancer treatment. Block copolymers are chosen based on the physicochemical characteristics of medicinal drugs. The amphiphilic block copolymer structure has both lipophilic and hydrophilic blocks, which enclose tiny hydrophobic molecules. It is a targeted drug delivery method because of its high effectiveness for drug retention in tissue, prevention of enzymes from degradation, and improvement of the cellular absorption mechanism. In an experimental environment, variations in temperature and solvent polarity stimulate copolymer micelle self-assembly. This is a thermodynamically guided procedure in which self-assembly happens by converting polymeric micelles. These aggregates go from a non-equilibrium to a thermodynamically equilibrium state, and they stay stable for a long time. The balance of thermodynamic and kinetic forces is critical in micelles self-assembly because the kinetic process predicts assembly behaviour and hierarchical structure. The purpose of this special issue is to provide an updated overview of micelles, a number of polymers and drugs commonly used in micellar preparation and their application.