Current Issue : October - December Volume : 2019 Issue Number : 4 Articles : 5 Articles
In this study, we proposed formulations of diminazene aceturate (DA) designed to improve\nits bioavailability and to maximize the therapeutic index in animals by overcoming the rapid\ndegradation under the acidic pH of the stomach. An important consequence is the fact that its amount\nin the bloodstream is close to the administered dose. This was made possible by incorporating DA\ninto the Beta-cyclodextrinâ??s (BetaCD) cavity in a molar ratio of 1:1. The structure of the resulted inclusion\ncomplex was established by Raman, DSC, andWide-Angle X ray DiBetaraction (WAXD) in solid state\nand by 1H-NMR and H-H ROESY in aqueous solutions. The stoichiometry of the DA:BetaCD inclusion\ncomplex was obtained by using the continuous variation method (Jobâ??s plot), considering the chemical\nshifts variations of protons from both DA and BetaCD compounds in 1H-NMR spectra. The biological\nactivity was estimated in vitro by antioxidant activity and in vivo by comparing the bioavailability of\nparent DA and its inclusion complexes after a single dose administration in Wistar rats by using the\nHPLC method on their blood plasma. In vitro tests showed an improved antioxidant activity. In vivo\ntests have shown that the DA concentration is always much higher in blood plasma of rats when\nDA:BetaCD inclusion complex of 1:1 molar ratio was administered (i.e., at 60 min, DA is around 11 and\n3 times higher when DA:BetaCD inclusion complex of 1:1 molar ratio was administered than the parent\nDA one and DA:BetaCD lyophilized mixture of 1:2 molar ratio, respectively)....
The influence of lignin modification on drug release and pH-dependent releasing behavior\nof oral solid dosage forms was investigated using three different formulations. The first formulation\ncontains microcrystalline cellulose (MCC 101) as the excipient and paracetamol as the active\npharmaceutical ingredient (API). The second formulation includes Alcell lignin and MCC 101\nas the excipient and paracetamol, and the third formulation consists of carboxylated Alcell lignin,\nMCC 101 and paracetamol. Direct compaction was carried out in order to prepare the tablets. Lignin\ncan be readily chemically modified due to the existence of different functional groups in its structure.\nThe focus of this investigation is on lignin carboxylation and its influence on paracetamol control\nrelease behavior at varying pH. Results suggest that carboxylated lignin tablets had the highest drug\nrelease, which is linked to their faster disintegration and lower tablet hardness....
Cellulose is among the top 5 excipients used in the pharmaceutical industry. It has been\nconsidered one of the main diluents used in conventional and modern dosage forms. Therefore,\ndifferent raw materials of plant origin have been evaluated as potential alternative sources of cellulose.\nIn this context, Opuntia ficus-indica L. Miller (palma forrageira), a plant of the cactus family that\nhas physiological mechanisms that provide greater productivity with reduced water requirements,\nis an interesting and unexplored alternative for extracting cellulose. By using this source, we aim\nto decrease the extraction stages and increase the yields, which might result in a decreased cost\nfor the industry and consequently for the consumer. The aim of this work was to investigate the\nuse of Opuntia ficus-indica L. Miller as a new source for cellulose extraction, therefore providing an\nefficient, straight forward and low-cost method of cellulose II production. The extraction method is\nbased on the oxidation of the lignins. The obtained cellulose was identified and characterized by\nspectroscopic methods (FTIR and NMR), X-ray diffraction, thermal analysis (TGA-DTG and DSC)\nand scanning electron microscopy. The results confirmed the identity of cellulose and its fibrous\nnature, which are promising characteristics for its use in the industry and a reasonable substrate for\nchemical modifications for the synthesis of cellulose II derivatives with different physicochemical\nproperties that might be used in the production of drug delivery systems and biomaterials....
Microcrystalline cellulose (MCC) aerogels were synthesized, blendingwith high amylose\ncorn starch of different contents based on a NaOH-urea solution, and following by vacuum\nfreeze-drying technology. The microstructure of the aerogel was observed by scanning electron\nmicroscopy (SEM) as an interconnected, porous three-dimensional structure, while X-ray diffractogram\n(XRD) measurements showed that the crystalline form was converted from cellulose I to cellulose II\nduring dissolution and regeneration. Thermogravimetric analysis (TGA) showed that the content of\nstarch had little effect on the thermal stability of the aerogel, whereas the content of starch had great\ninfluences on absorption and viscoelastic properties. When the ratio of starch was 10% and 15%, the\nprepared aerogels presented a low density and abundant pores, which endowed the aerogels, not\nonly with the highest absorption ratio of pump oil and linseed oil (10.63 and 11.44 g/g, respectively),\nbut also with better dynamic viscoelastic properties....
It is known that males and females respond differently to medicines and that differences\nin drug behaviour are due to inter-individual variability and sex specificity. In this work, we have\nexamined the influence of pharmaceutical excipients on drug bioavailability in males and females.\nUsing a rat model, we report that a portfolio of polyoxyethylated solubilising excipients (polyethylene\nglycol 2000, Cremophor RH 40, Poloxamer 188 and Tween 80) increase ranitidine bioavailability in\nmales but not in females. The in vivo sex and excipient effects were reflected in vitro in intestinal\npermeability experiments using an Ussing chamber system. The mechanism of such an effect\non drug bioavailability is suggested to be due to the interaction between the excipients and\nthe efflux membrane transporter P-glycoprotein (P-gp), whose expression in terms of gene and\nprotein levels were inhibited by the solubilising agents in male but not in female rats. In contrast,\nthe non-polyoxyethylated excipient, Span 20, significantly increased ranitidine bioavailability in both\nmales and females in a non-sex-dependent manner. These findings have significant implications for\nthe use of polyoxyethylated solubilising excipients in drug formulation in light of their sex-specific\nmodulation on the bioavailability of drugs that are P-gp substrates. As such, pharmaceutical research\nis required to retract from a â??one size fits allâ?? approach and to, instead, evaluate the potential impact\nof the interplay between excipients and sex on drug effect to ensure effective pharmacotherapy....
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