Current Issue : July - September Volume : 2015 Issue Number : 3 Articles : 6 Articles
We have developed a new ââ?¬Å?drugââ?¬Â and approach that appear to be effective in reducing arterial age. This ââ?¬Å?drugââ?¬Â represents a\nlow, subtherapeutic dose of statin and sartan and particularly their low-dose combination. The improvement of arterial wall\ncharacteristics, also reflecting in a decrease of arterial age, was achieved after a short period of treatment (one month) with the\nabove-mentioned drugs. In addition, we have also implemented a new, innovative therapeutic approach, consisting of intermittent\n(cyclic) treatmentââ?¬â?alternating short ââ?¬Å?treatmentââ?¬Â periods andmuch longer ââ?¬Å?restââ?¬Â periods (when the beneficial effects are still present\nbut gradually decline). This new ââ?¬Å?drugââ?¬Â and approach both merit further investigation in order to confirm their antiaging efficacy....
Thepurpose of this study was to examine the degradative effect of weakly basic nucleophilic drugs on a lactide-co-glycolide (PLGA)\npolymer in a microsphere formulation. Biodegradable PLGA microspheres of two second-generation atypical antipsychotics,\nRisperidone and Olanzapine, were manufactured using a solvent extraction/evaporation technique. The effect of drug content,\nbuffer pHand temperature on polymer molecular weight and degradation,were examined via a series of experiments and compared\nagainst a control (Placebo PLGA microspheres). In comparison to Placebo microspheres, significant polymer molecular weight\nreduction was observed upon encapsulation of varying levels of either Risperidone or Olanzapine. There was excellent correlation\nbetween the extent of molecular weight reduction during manufacture and the amount of encapsulated drug in the microspheres.\nSubsequent studies on polymer degradation showed: the following (a) the Placebo and Olanzapine microspheres followed pseudo\nfirst order kinetics, (b) Risperidone microspheres exhibited biphasic degradation profiles, and (c) polymer degradation was\ndependent on temperature, not pH. The findings of these studies show that encapsulation of weakly basic nucleophile type drugs\ninto PLGA can accelerate the biodegradation of the PLGA and have major implications on the design of polymeric microsphere\ndrug delivery systems....
Galantamine hydrobromide is formulated in tablets and capsules prescribed through oral delivery for the treatment of\nAlzheimer�s disease. However, oral delivery of drugs can cause severe side effects such as nausea, vomiting, and gastrointestinal\ndisturbance. Transdermal delivery of galantamine hydrobromide could avoid these unwanted side effects. In this work, galantamine\nhydrobromide was formulated in gel drug reservoir which was then fabricated in the transdermal patch. The in vitro drug release\nstudies revealed that the drug release from the donor chamber to receptor chamber of Franz diffusion cell was affected by the\namount of polymer, amount of neutralizer, amount of drug, types of permeation enhancer, and amount of permeation enhancer.\nVisual observations of the gels showed that all formulated gels are translucent, homogeneous, smooth, and stable. These gels have\npH in the suitable range for skin. The gel also showed high drug content uniformity. Hence, this formulation can be further used\nin the preparation of transdermal patch drug delivery system....
Background: The aim of current study was to investigate the way dose is prescribed to lung lesions during SBRT\nusing advanced dose calculation algorithms that take into account electron transport (type B algorithms). As type A\nalgorithms do not take into account secondary electron transport, they overestimate the dose to lung lesions. Type\nB algorithms are more accurate but still no consensus is reached regarding dose prescription. The positive clinical\nresults obtained using type A algorithms should be used as a starting point.\nMethods: In current work a dose-calculation experiment is performed, presenting different prescription methods. Three\ncases with three different sizes of peripheral lung lesions were planned using three different treatment platforms. For each\nindividual case 60 Gy to the PTV was prescribed using a type A algorithm and the dose distribution was recalculated using\na type B algorithm in order to evaluate the impact of the secondary electron transport. Secondly, for each case\na type B algorithm was used to prescribe 48 Gy to the PTV, and the resulting doses to the GTV were analyzed.\nFinally, prescriptions based on specific GTV dose volumes were evaluated.\nResults: When using a type A algorithm to prescribe the same dose to the PTV, the differences regarding\nmedian GTV doses among platforms and cases were always less than 10% of the prescription dose. The\nprescription to the PTV based on type B algorithms, leads to a more important variability of the median GTV\ndose among cases and among platforms, (respectively 24%, and 28%). However, when 54 Gy was prescribed as\nmedian GTV dose, using a type B algorithm, the variability observed was minimal.\nConclusion: Normalizing the prescription dose to the median GTV dose for lung lesions avoids variability\namong different cases and treatment platforms of SBRT when type B algorithms are used to calculate the dose.\nThe combination of using a type A algorithm to optimize a homogeneous dose in the PTV and using a type B\nalgorithm to prescribe the median GTV dose provides a very robust method for treating lung lesions....
Purpose The therapeutic index (TI) is the range of doses at\nwhich a medication is effective without unacceptable adverse\nevents. Drugs with a narrow TI (NTIDs) have a narrow window\nbetween their effective doses and those at which they\nproduce adverse toxic effects. Generic drugs may be substituted\nfor brand-name drugs provided that they meet the recommended\nbioequivalence (BE) limits. However, an appropriate\nrange of BE for NTIDs is essential to define due to the potential\nfor ineffectiveness or adverse events. Flecainide is an antiarrhythmic\nagent that has the potential to be considered an\nNTID. This review aims to evaluate the literature surrounding\nguidelines on generic substitution for NTIDs and to evaluate\nthe evidence for flecainide to be considered an NTID.\nMethods A review of recommendations from various regulatory\nauthorities regarding BE and NTIDs, and publications\nregarding the NTID characteristics of flecainide, was carried\nout.\nResults Regulatory authorities generally recommend reduced\nBE limits for NTIDs. Some, but not all, regulatory authorities\nspecify flecainide as an NTID. The literature review demonstrated\nthat flecainide displays NTID characteristics including\na steep drug doseââ?¬â??response relationship for safety and efficacy,\na need for therapeutic drug monitoring of pharmacokinetic\n(PK) or pharmacodynamics measures and intra-subject variability\nin its PK properties.\nConclusions There is much evidence for flecainide to be considered\nan NTID based on both preclinical and clinical data. A\nclear understanding of the potential of proarrhythmic effects\nor lack of efficacy, careful patient selection and regular monitoring\nare essential for the safe and rational administration of\nflecainide....
Chitosan nanoparticles (CSNPs) have been extensively applied in medical and pharmaceutical fields as promising drug delivery\nsystems. Despite that, the safety of CSNPs remains inadequate and needs further investigation, particularly on hematopoietic\nstem cells (HSCs). CSNPs were prepared by ionic gelation method and later were characterized for their physical characteristics\n(particle size and zeta potential). Cytotoxicity of CSNPs was assessed by MTT assay. Particle size was highly influenced by chitosan\nconcentration and molecular weight (medium and highmolecular weight(MMWand HMW)).Higher chitosan concentration and\nmolecular weight produced larger nanoparticles. Zeta potential of CSNPs was not significantly affected by chitosan concentrations\nand molecular weights used in the present study. MMW had a better stability than HMW CSNPs as their particle size and zeta\npotential were not significantly altered after autoclaving. Cytotoxicity of CSNPs was influenced by zeta potential and particle size.\nOn the other hand, chitosan concentration and molecular weight indirectly influenced cytotoxicity by affecting particle size and\nzeta potential of CSNPs. In conclusion, cytotoxicity of CSNPs was mainly attributed to their physical characteristics and this opens\na strategy to ensure the safety of CSNPs applications in stem cell technology....
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