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Optical Nanoprobes for Diagnosis
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
R. G. Aswathy, D. Sakthi Kumar
Built-in multifunctional LDH structure within a single-phase NP before incorporating, conjugating with other phases is gaining greater interest [255]. LDHs or anionic clays or hydrotalcite-like compounds are clay-like materials that exhibit exciting properties for many applications. LDHs are a broad class of inorganic lamellar compounds with high capacity for intercalation of anion. The LDH structure is represented by [M2+1–xM3+x(OH)2]x+(An–)x/n · mH2O that results from the stacking of brucite-like layers ([Mg(OH)2]) with extra positive charge, owing to the partial isomorphous substitution of M2+ by M3+ [256–259]. The positive excess charge is well balanced by anions that are present in interlamellar spaces. The frequently used divalent cations are Mg2+, Cu2+, Ni2+, Co2+, Zn2+, Fe2+, and Mn2+, and trivalent cations include Al3+, Ni3+, Fe3+, Mn3+, Gd3+, and Cr3+. The natural mineral, hydrotalcite (Mg6Al2(OH)16CO3 · 4H2O), with space group R-3 m, has a typical LDH assembly, shown in Figure 7.15. The partial substitution of octahedral Mg2+, in the layered brucite (Mg(OH)2 stacks), with Al3+ generates positive charge on the piled layers. Specifically required anions are intercalated during synthesis and substitution of interlayer anions occurs after the synthesis through ion exchange. Charge neutrality is supported by the intercalation of bound anions through electrostatic binding in the interlayer space, with water through hydrogen bonding to hydroxyls. The commonly bound anions include nitrates, carbonates, organic acids, glycerol, porphyrins, nucleotides, DNA, ATP, vitamins, and drugs.
Layered double hydroxide nanoparticles as an appealing nanoparticle in gene/plasmid and drug delivery system in C2C12 myoblast cells
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Parivar Yazdani, Elham Mansouri, Shirin Eyvazi, Vahid Yousefi, Homan Kahroba, Mohammad Saeid Hejazi, Asghar Mesbahi, Vahideh Tarhriz, Mir Mahdi Abolghasemi
The XRD pattern of Zn/Al-LDH is shown in the range of 2θ = 2°–70° in Figure 2. The XRD pattern of the Zn/Al-LDH sample indicates characteristic diffractions of hydrotalcite (PDF: 00–011-0614). The diffraction peaks at 2θ = 11.64, 20.68, 34.85 and 61.04, respectively, correspond to the (003), (006), (009) and (110) of LDH well-crystallized structure. Correspondingly, lamellar and symmetrical structure of 3 R rhombic was confirmed. The basal spacing (d003) corresponding to Cl- ions between the interlayers was expected. The lattice parameters of a and c could be calculated from sever picks of (003), (006) and (110). Figure 2 showed that displacement of the main pick (basal spacing) towards the lower angles indicates main space alternation and valproic acid drug (guest anion) placement instead of primary anions. Angle reduction expresses an increase in the spacing of the layers.
Multicomponent crystals of gliclazide and tromethamine: preparation, physico-chemical, and pharmaceutical characterization*
Published in Drug Development and Industrial Pharmacy, 2018
Giovanna Bruni, Vittorio Berbenni, Lauretta Maggi, Piercarlo Mustarelli, Valeria Friuli, Chiara Ferrara, Francesca Pardi, Federica Castagna, Alessandro Girella, Chiara Milanese, Amedeo Marini
Gliclazide (1-1-azabicyclo 3,3,0 oct-3yl-3-p-tolyl sulfonylurea, G in the following) is a potent second-generation sulfonylurea antidiabetic agent. It is a drug of choice in long-term sulfonylurea therapy for the control of Type II non-insulin dependent diabetes mellitus; it shows good tolerability, low incidence of hypoglycemia, anti-platelet adhesive activity, and reduction of free radicals thus preventing vascular complications [1,2]. Rapid gastrointestinal absorption is required for oral hypoglycemic drugs to prevent a sudden increase in blood glucose level after food intake in diabetic patients. However, the absorption rate of gliclazide is slow because of its poor dissolution rate. Indeed, its solubility in water is very low (54 mg/L) [3]. Furthermore, as it is a weak acid (pKa = 5.8), its solubility is influenced by the pH values of gastric fluid and is subjected to inter-subject and intra-subject variability [1]. Therefore, several methods have been proposed for enhancing the dissolution rate of gliclazide. They include the reduction of particle size to increase the specific surface area available for dissolution [4], the formation of solid dispersions and of solid solutions to decrease the drug crystallinity [3,5–7], the intercalation in hydrotalcite-like compounds [8], the preparation of multicomponent crystals [8–10], and the complexation with cyclodextrins [11]. The high number of research papers concerning this issue demonstrates the great interest felt in the pharmaceutical world, and the true need for improving pharmaceutical behavior of gliclazide.
Management of a multiple endocrine neoplasia type 1 during pregnancy: a case with primary hypertension
Published in Gynecological Endocrinology, 2022
Jianyi Li, Dabao Xu, Xinli Liu
Pancreatic islet tumors comprise gastrinoma, glucagonoma, insulinoma, and vasoactive intestinal polypeptidoma, the most common cause of symptoms is a result of Zollinger-Ellison (gastrinoma) syndrome, finding can include upper-abdominal pain, esophageal reflux, diarrhea and acid-peptic ulcers. With duodenal ulcer and chronic superficial gastritis in our patient, she took oral hydrotalcite discontinuous during pregnancy. Glucagonomas are seen in less than 3% of the patients and may cause diabetes mellitus in 75–95% of them. As blood glucose level can usually be controlled with diet modification, oral medications and insulin, our patient used insulin during pregnancy and the blood glucose levels were controlled in normal range most of the time.