FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W581750380> ?p ?o ?g. }

• W581750380 abstract "High-performance liquid chromatographic methods are developed for the simultaneous determination of various salicylates, their p-hydroxy isomers and nicotinic acid esters. The method is sensitive enough to detect trace amounts (~µM/L)of the product generated from cross reactivity between the drugs and the vehicle. The developed method also allows analysis of various topical products containing salicylate and nicotinate esters in their formulations. Applying this method, the degradation profiles of salicylates, nicotinates, p-hydroxy benzoate, o-methoxy benzoate and aspirin prodrugs in alkaline media are determined. The profile for alkyl salicylate degradation is found to be first order (A---? B) When the alcoholic radical is similar to that of the ester. In alcohol having a radical different from that of the ester function, the degradation is found to proceed through competitive transesterification and hydrolysis. The intermediates are identified following synthesis and isolation. The rate and extent of transesterification depends on the proportion of alcohol present in the system. Equations are presented to model the time profiles of reactant and product concentration. The reactions are base catalysed and the predominant pathway involves a concerted solvent attack upon the salicylate anion. Competitive hydrolysis of both ester components also follows this mechanism at moderate pH values but rates increase under strongly alkaline conditions as direct hydroxide attack becomes significant. In contrast, transesterification is independent of base concentration once full ionization is accomplished. The competitive hydrolysis is modelled using equations involving the dielectric constant of the medium. A range of other esters are also shown to undergo base-catalysed transesterification. In non-alcoholic solution phenyl salicylate undergoes a concentration-dependent oligomerisation which yields salsalate among the products. Competitive transesterification and hydrolysis also occur in products for topical use which have vehicles based upon alcohol, glycol or glycol polymers. Such reactions may compromise stability assessments, pharmaceutical integrity and delivery profiles." @default.
• W581750380 created "2016-06-24" @default.
• W581750380 creator A5089194993 @default.
• W581750380 date "1985-02-01" @default.
• W581750380 modified "2023-09-27" @default.
• W581750380 title "The stability and formulation of topical analgesics" @default.
• W581750380 hasPublicationYear "1985" @default.
• W581750380 type Work @default.
• W581750380 sameAs 581750380 @default.
• W581750380 citedByCount "0" @default.
• W581750380 crossrefType "dissertation" @default.
• W581750380 hasAuthorship W581750380A5089194993 @default.
• W581750380 hasConcept C121332964 @default.
• W581750380 hasConcept C148898269 @default.
• W581750380 hasConcept C161790260 @default.
• W581750380 hasConcept C178790620 @default.
• W581750380 hasConcept C185592680 @default.
• W581750380 hasConcept C2775896084 @default.
• W581750380 hasConcept C2777241282 @default.
• W581750380 hasConcept C2780471494 @default.
• W581750380 hasConcept C2781066024 @default.
• W581750380 hasConcept C43617362 @default.
• W581750380 hasConcept C62520636 @default.
• W581750380 hasConcept C90932021 @default.
• W581750380 hasConcept C93391505 @default.
• W581750380 hasConcept C94412978 @default.
• W581750380 hasConceptScore W581750380C121332964 @default.
• W581750380 hasConceptScore W581750380C148898269 @default.
• W581750380 hasConceptScore W581750380C161790260 @default.
• W581750380 hasConceptScore W581750380C178790620 @default.
• W581750380 hasConceptScore W581750380C185592680 @default.
• W581750380 hasConceptScore W581750380C2775896084 @default.
• W581750380 hasConceptScore W581750380C2777241282 @default.
• W581750380 hasConceptScore W581750380C2780471494 @default.
• W581750380 hasConceptScore W581750380C2781066024 @default.
• W581750380 hasConceptScore W581750380C43617362 @default.
• W581750380 hasConceptScore W581750380C62520636 @default.
• W581750380 hasConceptScore W581750380C90932021 @default.
• W581750380 hasConceptScore W581750380C93391505 @default.
• W581750380 hasConceptScore W581750380C94412978 @default.
• W581750380 hasLocation W5817503801 @default.
• W581750380 hasOpenAccess W581750380 @default.
• W581750380 hasPrimaryLocation W5817503801 @default.
• W581750380 hasRelatedWork W1496088757 @default.
• W581750380 hasRelatedWork W1833684078 @default.
• W581750380 hasRelatedWork W1972567337 @default.
• W581750380 hasRelatedWork W1988320424 @default.
• W581750380 hasRelatedWork W1988861258 @default.
• W581750380 hasRelatedWork W2011292839 @default.
• W581750380 hasRelatedWork W2016214859 @default.
• W581750380 hasRelatedWork W2021654270 @default.
• W581750380 hasRelatedWork W2033834795 @default.
• W581750380 hasRelatedWork W2042186844 @default.
• W581750380 hasRelatedWork W2058328716 @default.
• W581750380 hasRelatedWork W2063119560 @default.
• W581750380 hasRelatedWork W2094866786 @default.
• W581750380 hasRelatedWork W2153409593 @default.
• W581750380 hasRelatedWork W2273880451 @default.
• W581750380 hasRelatedWork W2351401922 @default.
• W581750380 hasRelatedWork W2384156277 @default.
• W581750380 hasRelatedWork W258950510 @default.
• W581750380 hasRelatedWork W2921686694 @default.
• W581750380 hasRelatedWork W2921756253 @default.
• W581750380 isParatext "false" @default.
• W581750380 isRetracted "false" @default.
• W581750380 magId "581750380" @default.
• W581750380 workType "dissertation" @default.