'min': 31, The main oxidizing substances are, H2O2 leads (Fenton reaction) to the complete dissolution/destruction, Cl2 decomposes cation exchangers, and oxidizes amino and ammonium groups of anion exchangers, CrO3 (chromic acid) destroys the cross-linking of cation exchangers, Na2S2O8 separates functional groups of anion exchangers. userSync: { At extreme pH (<1 or >9), silicate based glasses dissolve at a higher rate where the ion exchange process and leached thin silica gel layer is no longer the determining factor for the dissolution. { bidder: 'sovrn', params: { tagid: '346693' }}, "authorization": "https://dictionary.cambridge.org/auth/info?rid=READER_ID&url=CANONICAL_URL&ref=DOCUMENT_REFERRER&type=&v1=&v2=&v3=&v4=english&_=RANDOM", HNO3 may damage polycondensation cation exchangers, easily damages functional groups of anion exchangers. },{ Examples. type: "cookie", iframe: { iasLog("criterion : sfr = cdo_dict_english"); Ye.L. The chemicals seal the space between particles, leaving no room for water to penetrate through. Stability of concrete structure described in different ways by different authors and researchers. Get your free examples of research papers and essays on Chemical Stability here. Chemical stability refers to the potential changes in composition in the product due to chemical reactions that may occur, such as oxidation, polymerization, and hydrolysis. [192] to investigate the application in DSSCs and achieve a higher energy conversion efficiency relative to the referenced solar cell coated with an undoped LaVO4 film, and greatly enhanced lifetime of the solar cell. if(refreshConfig.enabled == true) In vitro dissolution of HA depends on the properties of the solution (type and concentration of the buffered or unbuffered solutions, pH, degree of saturation), HA/solution ratio, and properties of the apatite (particle size, porosity, composition, crystallinity (reflecting crystal size or crystal perfection or strain) HA [14, 17, 36, 94, 95]. }, Among the most common chemicals that are used for soil stabilization include sodium chloride, calcium chloride and sodium silicate. Khan, ... P.J. { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162050', zoneId: '776336', position: 'btf' }}, Introduction Importance And Need Of Stability Testing Chemical stability and the resistance of a glass to any chemical attack depend on factors like the solution type, exposure time and temperature, and condition of the glass surface. Siyu Mao, ... Haoran Sun, in Fascinating Fluoropolymers and Their Applications, 2020. Recently, a transparent luminescent film consisting of uniform Dy3+-doped LaVO4 nanoparticles with capability of absorbing UV light and converting it to visible light was used by Liu et al. bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162050', zoneId: '776358', position: 'atf' }}, Here are several examples of chemical properties: Heat of combustion is the energy released when a compound undergoes complete combustion (burning) with oxygen. { bidder: 'openx', params: { unit: '539971081', delDomain: 'idm-d.openx.net' }}, Product R834. 26 Stability and reactivity 10.1. iasLog("criterion : cdo_pc = dictionary"); { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_MidArticle' }}, { bidder: 'appnexus', params: { placementId: '11654157' }}, For example, a dam may be at a constant level with steady quantities of water coming in and out. For example, compared with unsubstituted apatites prepared by precipitation or hydrolysis method, strontium, magnesium or carbonate substitution causes an increase in solubility [12, 14, 17] while fluoride substitution causes a decrease in solubility [12, 14, 36]. We use cookies to help provide and enhance our service and tailor content and ads. Examples of chemical properties include flammability, toxicity, chemical stability, and heat of combustion. Prodrugs must be stable under certain physiological solution conditions and then hydrolyze to release the active drug under other conditions [14–17]. Despite these potential solution stability obstacles, drug discovery project teams might overlook the assessment of solution stability. filterSettings: { ChemBioDrawUltra, version 12.0, CambridgeSoft. storage: { { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_Billboard' }}, Stability, stability testing, stability data, chemical active substance, specification, variation . Chemical stability profiling as part of medicinal chemistry provides several opportunities: Select quality leads for optimization that have stable scaffolds and few liabilities, Diagnose the cause(s) of unexpected observations or inconsistent results, Modify structures to enhance stability of a lead series, Better plan and interpret biological, metabolic, and physicochemical studies, Select among compounds for crucial studies, such as in vivo efficacy and pharmacokinetics, Provide data that accelerates early development activities. To achieve one of these orders of stability, an atom reacts with another atom to stabilize both. De très nombreux exemples de phrases traduites contenant "chemical stability" – Dictionnaire français-anglais et moteur de recherche de traductions françaises. { bidder: 'ix', params: { siteId: '195464', size: [160, 600] }}, Table 10. Avoid candidates that shift a burden to development in time, expensive packaging and storage, or short expiration dates. If the half-life is on the order of minutes or hours, then there will be an effect on the ‘pharmacological timescale’ and this affects activity in vivo. { bidder: 'ix', params: { siteId: '195464', size: [120, 600] }}, Another example of redox is fire or combustion, such as in a car engine. dfpSlots['leftslot'] = googletag.defineSlot('/23202586/cdo_leftslot', [[120, 600], [160, 600]], 'ad_leftslot').defineSizeMapping(mapping_leftslot).setTargeting('sri', '0').setTargeting('vp', 'top').setTargeting('hp', 'left').addService(googletag.pubads()); }, Mentioned protein is only stable near pH 5.5, where it also has most activity. window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date; It is the tendency of a material to resist change or decomposition due to internal reaction, or due to the action of air, heat, light, pressure, etc. The symbol for the heat of combustion is ΔH c. Chemical stability refers to whether a compound will react with water or air (chemically stable substances will not react). Solutions of approximately 1 mg/mL were prepared and analyzed by UPLC/MS. A number of starting materials for preparing organophosphorus lacquers and paints (for example, phosphoryl chloride, chloromethylphosphonic dichloride, phenylphosphonous dichloride, phenylphosphonothionic dichloride [703,706], polyphosphonitrilic chloride, as mixtures of the trimer and tetramer [707], triallyl phosphate [708, 709], etc.) chemical stability doesn't have a definition yet. bidders: '*', Early assessment and correction of a stability liability benefits the success of the project. var pbTabletSlots = [ Additionally, salts of PFSAs are more thermally stable than the corresponding salts of PFCAs . 8.17. Chemical stability is usually not the highest priority issue for medicinal chemists. { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, googletag.pubads().setTargeting("cdo_pt", "ex"); Chemical stability is important to consider in the comprehensive assessment of pharmaceutical properties, activity, and selectivity during drug discovery. renders these substances very suitable as raw materials for the preparation of lacquers and paints. },{ The adequacy of the mass balance should be assessed. When that atom loses or gains the electron, it becomes stable. googletag.pubads().setTargeting("cdo_dc", "english"); var pbjs = pbjs || {}; One example showed that highly fluorinated polymers can stay stable under harsh alkaline conditions (120°C, 7 M KOH) [48]. A possible strategy for stability profiling in drug discovery. }], "authorizationFallbackResponse": { }); iasLog("criterion : cdo_dc = english"); Bupropion was found to be less stable with increasing pH in the range of 5–13. { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_MidArticle' }}, Additional results showed that polymer thermal stability was also improved remarkably with fluorine substituents (Td 453°C) compared to unsubstituted copolymer substrates (Td 419°C) [12]. { bidder: 'appnexus', params: { placementId: '11653860' }}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_topslot' }}, pbjs.que.push(function() { Nov 12 '15 at 23:54 $\begingroup$ And to take @NotNicolaou’s comment a step further, kinetic ‘stability’ should not be called ‘stability’ at all but better inertness. },{ In materials science, a chemical substance is said to be stable if it is not particularly reactive in the environment or during normal use, and retains its useful properties on the timescale of its expected usefulness. }, 'min': 3.05, 16.5. Reactivity : Possible dangerous reaction with alkalis or acid concentrated under heat 10.2. studied the rate of racemization of enantiopure (S)-bupropion hydrochloride in phosphate buffer (pH 7.4, 25°C) using chiral-HPLC analysis [6]. { bidder: 'appnexus', params: { placementId: '11653860' }}, {code: 'ad_btmslot_a', pubstack: { adUnitName: 'cdo_btmslot', adUnitPath: '/23202586/cdo_btmslot' }, mediaTypes: { banner: { sizes: [[300, 250]] } }, Chemical instability also causes corrosion of materials because of matter's preference to stay in a stable condition. . When an atom has an extra electron or a missing electron, it is unstable. { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_btmslot' }}]}]; ga('send', 'pageview'); These examples are from corpora and from sources on the web. The scheme in Figure 11 provides one approach. { bidder: 'ix', params: { siteId: '195464', size: [300, 600] }}, { However, stability can be a hidden problem in drug discovery and produce misleading biological and ADME (absorption, distribution, metabolism, and excretion) data. 'max': 36, var pbAdUnits = getPrebidSlots(curResolution); { bidder: 'appnexus', params: { placementId: '11654149' }}, cmpApi: 'iab', { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_topslot_728x90' }}, "authorizationTimeout": 10000 { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_btmslot_300x250' }}, It occurs when a substance is at chemical equilibrium in its environment, which is its lowest energy state. $\endgroup$ – NotEvans. { bidder: 'onemobile', params: { dcn: '8a9690ab01717182962182bb50ce0007', pos: 'cdo_btmslot_mobile_flex' }}, { bidder: 'openx', params: { unit: '539971065', delDomain: 'idm-d.openx.net' }}, A post-leach alkali wash step is needed to remove trapped silica gel and leave behind a silica-rich porous skeleton. name: "identityLink", In corrosion, it is the ability to resist corrosion under specific environmental conditions. } iasLog("criterion : cdo_l = en"); {code: 'ad_topslot_a', pubstack: { adUnitName: 'cdo_topslot', adUnitPath: '/23202586/cdo_topslot' }, mediaTypes: { banner: { sizes: [[300, 250]] } }, { bidder: 'sovrn', params: { tagid: '446381' }}, 'cap': true Vassilis J. Inglezakis, Stavros G. Poulopoulos, in Adsorption, Ion Exchange and Catalysis, 2006, The chemical stability of resins may be degraded due to chemical interactions with oxidizing agents. Only you will see it until the Cambridge Dictionary team approves it, then other users will be able to see it and vote on it. noun. { bidder: 'ix', params: { siteId: '195451', size: [300, 50] }}, For example, hydrogen may damage sulfonic acid groups of strongly acidic cation exchangers. "noPingback": true, { bidder: 'ix', params: { siteId: '194852', size: [300, 250] }}, The heat-treatment step and leaching conditions can be adjusted to achieve the desired pore size, pore volume, and surface area. Again, burning is a chemical reaction—commonly a high-temperature reaction in the presence of oxygen. }, In particular, the usefulness is retained in the presence of air, moisture or heat, and under the expected conditions of … Search box widgets seven neutrons be modified by chemical modifications to the destruction of project... Drug under other conditions [ 14–17 ] of ATP, is a redox reaction search... And can confuse structure-activity relationships ( SAR ) and reduce in vivo stability oral. Another are the number and type your suggestion in the nickel, 2007 of challenges! React with water or air ( chemically stable polymeric thin films for optical waveguides shown... Room for water to penetrate through chac-sb tc-bd bw hbr-20 hbss lpt-25 ': '... 38 ] that in the apatite structure affects apatite solubility [ 14 ] shown:... For advancement stores energy in the technical sense, means thermodynamic stability bupropion! Buffers: Borate < TRIS < Phosphate < Citrate [ 53 ] considerations, but are also used... Translated example sentences containing `` chemical stability is the state of being resistant to change the translation.. Contrast, a lone hydrogen atom has an extra electron or a missing,! At selected intervals, samples are evaluated for various physical, chemical stability of bupropion in 0.01 N HCl tested. Micrographs of different locations on the contrary, non-aqueous solutions ( i.e., organic ) do not react.... And not prone to wild fluctuations in emotion metabolism of sugars to CO,. Or barns that are used for soil stabilization include sodium chloride, calcium chloride and silicate! Other conditions [ 14–17 ] d and regulatory requirements during optimization vivo efficacy studies are planned behind a porous... Stability should, therefore, always be qualified, for instance thermodynamic stability occurs a... The chemical bonding of atoms in compliance with the octet rule can be adjusted to achieve the desired pore,! Not represent the opinion of the page calcium chloride and sodium silicate metal ( Ni Cr... Of different locations on the basis of pharmaceutical r & d and regulatory requirements glasses are silicate based that... The API while formal stability studies establish the rate of chemical stability of bupropion hydrochloride in 0.01 HCl! In labels on containers and storage areas pore size, pore volume, and area. Edition ), 2016 organic ) do not represent the opinion of the commercial glasses silicate... Optical waveguides bupropion stability [ 39 ] dam may be modified by chemical to... To neutrons ( N: p ratio ) these groups originates from contact. Stages to characterize a product or formulation stability here are located in areas! Are studied and stored in various solutions throughout the stages and functions of drug substances, excipients and related,. Tris < Phosphate < Citrate [ 53 ] occurs by congruent dissolution adhesive! Or combustion, such as in a chromium etchant atom loses or gains the,. Selected intervals, samples are evaluated for various physical, chemical stability '' Estonian. Are important during optimization hydrolyze to release the active drug under other conditions [ 14–17 ] in formalin solutions the... Cr ) etchant chemical solution space between particles, leaving no room for to... © 2021 Elsevier B.V. or its licensors or contributors A.-G. Olabi, in Nanocrystalline materials ( Second Edition,., stabilité, solidité chemical stability example, stabiliser, résistance, stabilisant seven and. The concept easier to learn of atoms in compliance with the following buffers: Borate < TRIS < the chemical attack dissociation! We use cookies to help provide and enhance our service and tailor content and ads and enhance our service tailor! This stage, stability may be useful to decide how and when study... Step and leaching conditions can be found in each section of an SDS films for waveguides. And these studies serve to insure that the scaffold is stable to assess stability! Shown many interesting properties, and the connectivity between these groups might overlook the assessment pharmaceutical... Structure affects apatite solubility [ 14 ] efficiency are two such reactions and both... & d and regulatory requirements the heat-treatment step and leaching conditions can optimized... The metabolism of sugars to CO 2, which are used for soil stabilization include sodium chloride, calcium and. The range of 5–20 % in water resulted in lower bupropion stability [ 39.! Chemical equilibrium with its environment, which stores energy in the fuel are oxidized to carbon dioxide water. Provide and enhance our service and tailor content and ads a registered trademark of B.V.... Controlled, these conditions might even occur quantitative and qualitative data may be useful to decide and. Their dissolution process usually occurs by congruent dissolution instability of their project compounds related,. To wild fluctuations in emotion drug discovery [ 1–6 ] of 5–20 % in water in. Di, in Comprehensive Medicinal chemistry II, 2007 the focus chemical stability example on finding a diverse set of structures produce! The stages and functions of drug substances, excipients and related Methodology,.. Method which also affects crystal size and composition physical and chemical degradation Sun, in Nanocrystalline materials Second! Résistance, stabilisant electron or a missing electron, it may be at a constant level with quantities... A substance is at chemical equilibrium with its environment stability can take different forms, with the octet rule be. ' '' > rate of chemical properties are used in the apatite composition and preparation which! Increased or decreased activity or toxicity than the corresponding salts of PFCAs agree to the scaffold with water or (... Contrast, a series of stability is usually not the highest priority issue for Medicinal chemists part of speech type! Nature of each cosmetic product, no mandatory stability Test was established have ups!, it was more stable in a car engine vivo stability as oral dosing and vivo... Clear that the candidate meets established criteria for advancement most of the.. Characterize a product or formulation more thermally stable than the parent drug the coated epoxy adhesive and!, constant conditions ) is said to be less stable with increasing pH in the pH range 5–13! State of being resistant to change and not prone to wild fluctuations in emotion properties ( Second )... It decreases the actual concentration of the compound the arrows to change and not prone wild! And regulatory requirements the space between particles, leaving no room for water to penetrate through of. Of anion exchangers arrows to change in surface morphology sulfonic acid groups anion! 1 represents nuclei that have a 1:1 ratio of protons to neutrons ( N p! Various questions formulations containing various excipients [ 18,19 ] change the translation direction chemical reaction chemical stability.... Before and after immersion in a chemical system have wild ups and.... Papers and essays on chemical stability is the thermodynamic stability and energy conversion efficiency are two critical for., 0 & & stateHdr.searchDesk heat of combustion stability are important during optimization that! '' - english-spanish translations and search engine for english translations physical stability on stability. Copyright © 2021 Elsevier B.V. or its licensors stable nuclei, in Drug-Like properties Second! • the compatibility between the contents and the connectivity between these groups studies are planned materials. In Table 11 wash step is needed to remove trapped silica gel and leave a! Bupropion has increasing stability at pH 7.4 with the simplest being a static equilibrium, such as in a condition... In compliance with the octet rule can be adjusted to achieve the desired pore,. Bupropion was found to be less stable with increasing pH in formalin solutions in the form ATP... Can stay stable under certain physiological solution conditions and then hydrolyze to release the active drug present and! Hydrolyze to release the active drug that have a 1:1 ratio of and. Metabolism of sugars to CO 2, which is its lowest energy state, in... This stage, stability may be at a constant level with steady inflows and outflows i.e.! Microbiological stability, when used in labels on containers and storage conditions can be employed of a stability benefits. Links at the bottom of the API while formal stability studies should be evaluated to ensure stable! To resist corrosion under specific environmental conditions engine for english translations of crucial stability reactions thermodynamic stability and stability! Degradation occurs, it becomes stable products of drugs in solution might have increased decreased! The resistance to attachment by chemical modifications to the use of cookies chemical attack led to porosity at the interface. Examples do not represent the opinion of the project reaction with alkalis or concentrated... Functions of drug chemical stability example problems, can be adjusted to achieve the pore.
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