Detection of Metabolites of Vecuronium Bromide in Visceral Samples Solves A Typical Death Mystery- (Toxicokinetics- Studies Using Gc-Ms Technique).

Introduction: On Sudden death of a medical student (20 year old girl) of National Institute of Medical Science autopsy materials along with site of injection were sent to F.S.L. It was informed during investigation that the girl took tetanus vaccine before death. In crime scene investigation Forensic Team observed that it was a case of gross negligence of dispensing wrong injection. Material: Tests were performed on viscera material viz., liver, spleen, kidney, lungs, brain, skin and blood etc. Mystery of suspected death was solved when a new GC-MS application was designed to get the unknown drug and various fragments of extracted material were studied. Method: A new method was developed on gas-chromatography-mass spectrophotometer and TL.C using various solvent systems is explained. Results: Metabolite fragments of vecuronium bromide a muscle relaxant were surprisingly observed in Viscera material, Blood sample and Skin piece from Leftt cubital fossa from this young girl, whose death is questioned. Conclusion: Structural elucidations of fragments provide a new approach to toxicokinetics. Th e explanation of fragments obtained were structurally compared with other neuromuscular blocking groups like atracurium and succinyl choline Th e presence of bromide attached cholest-5-en-Br, hydroxylated cholest-5-en-ol as hydroxylated product, acetylated fragments as cholest-5-enacetate and piperidone-2-one present in visceral samples indicates structural part obtained from vecuronium bromide drug. Th ese metabolites studies makes the case studies highly informative. Beside this new method of extractions, TLC systems and colouring reagents are also explained.

Desenvolvimento, validação e comparação de métodos analíticos para determinação de bloqueadores neuromusculares derivados de esteróides / Development, validation and comparison of analytical methods for determination of neuromuscular blocking derivatives of steroids

Os relaxantes neuromusculares não despolarizantes são fármacos indispensáveis nos procedimentos cirúrgicos que requerem entubação endotraqueal, visto que diminuem o tônus muscular. Quimicamente são divididos em derivados isoquinolinicos e derivados de esteróides, esses últimos com maior aplicação clinica e comercialização no Brasil. Assim sendo, é importante a validação de métodos analíticos para o controle de qualidade com alternativas confiáveis que garantam sua eficácia e segurança. Os brometos de vecurônio, de pancurônio e de rocurônio são fármacos relaxantes neuromusculares não despolarizantes derivados de esteróides. As propriedades farmacológicas destes fármacos são significativamente diferentes entre si, porém, as propriedades químicas são bastante similares. Na presente pesquisa foram desenvolvidos e validados métodos analíticos de separação (cromatografia líquida de alta eficiência e eletroforese capilar) para cada fármaco. Estes métodos foram aplicados a medicamentos comercializados no Brasil. Para todos os métodos cromatográficos foi utilizada uma coluna amino devido a seu caráter polar. Em função da baixa absorção dos três fármacos na região ultravioleta, os métodos eletroforéticos foram aplicados com detecções indiretas utilizando substâncias cromóforas. Comparando-se as técnicas utilizadas para determinação dos fármacos nos medicamentos isoladamente, não houve diferença significativa com nível de confiança de 95,0%. Nos testes de hipótese aplicados (F-Snedecor e t-Student), não foram observadas diferenças na precisão (variâncias) e no valor encontrado dos fármacos contidos nas amostras estudadas (comparação de duas médias).

The non-depolarizing neuromuscular relaxant drugs are essential in surgical procedures requiring endotracheal intubation, as they decrease muscle tonics. These drugs are chemically divided in isoquinolines derivatives and steroid derivatives, this latter group, with greater clinical application and commercialization in Brazil. Therefore, the study and validation of analytical methods are important for quality control with reliable alternatives to ensure their effectiveness and safety. The vecuronium, pancuronium and rocuronium bromides are steroid derivatives presenting non-depolarizing neuromuscular relaxant action. Pharmacological properties of these drugs differ significantly, however, its chemical properties are quite similar. In this research, analytical separation methods (high performance liquid chromatography and capillary electrophoresis), for each drug, were developed and fully validated. The methods were applied to pharmaceutical formulations commercialized in Brazil. For all chromatographic methods, an amino column was used, due to its polar characteristics. Due to the low absorption of the three drugs in the ultraviolet region, electrophoretic methods has been applied with indirect detection using chromophoric substances. When comparing both techniques used for quantitative determination of these drugs in pharmaceutical products, no significant difference was observed using a confidence level of 95.0%. By applying hypothesis tests (F-Snedecor and t-Student), it was not observed difference in precision (variance) and in the found amount of drugs contained in the selected samples (comparison of two means).

Interaccion vecuronio-rocuronio revisada por la comparacion de su potencia relativa / Interaction between vecuronium and rocuronium: revaluation by their relative potencies

Existen varios métodos para el estudio de la interacción entre bloqueadores musculares y otros tantos para elcálculo de la curva dosis respuesta. El presente trabajo analiza la interacción entre el vecuronio y rocuronio comparando las potencias respectivas obtenidas del control con el de las mezclas, calculadas para cada paciente. En primer lugar se concluyó la relación dosis-respuesta con el uso de dosis subparalíticas únicas, administrando vecuronio 10, 20 y 30 ug. Kg-¹ o rocuronio 50, 100 y 200 ug.Kg-¹. Utilizando el máximo efecto se determinaron las dosis efectivas-50 y 95 (DE50 – 95) resolviendo la ecuación de Hill para cada paciente considerando 4,75 como coeficiente. Seguidamente se repitieron los cálculos después de administrar fracciones equipotenciales que representan 0.2, 0.3 y 0.4 x DE50 de ambas drogas. Con ayuda del análisis algebraico se identificó el tipo de interacción: [dv / (DE50-95) v + dr/(DE50-95) r] y que demostró un valor ligeramente menor de uno [1] lo cual indica aditivismo. Todas las cifras que se obtuvieron guardan gran similitud con los provenientes de otros métodos y sugieren que el presente es una herramienta sencilla, confiable y útil para el cálculo de la relación dosis-respuesta en general y para estudiar la interacción entre vecuronio y rocuronio en particular.

There are several methods for the study of the interaction between neuromuscular blockers and as many tocalculate their dose-response curve. The present trial deals with the interaction between vecuronium and rocuronium assessed by comparison of their respective potencies obtained for a control with that of their mixtures, both calculated for each patient. Drug potency was obtained first after the administration of single no paralytic doses: vecuronium 10, 20 and 30 ug. Kg-¹ or rocuronium 50, 100 and 200 ug. Kg-¹. Using maximal effect, 50 and 95 effective doses (ED50 – 95) were determined by solving Hill equation for each subject, considering 4.75 as the coefficient. The same procedure was repeated after the administration of 0.2, 0.3 or 0.4 x ED50 of both drugs. Algebraic analysis was used to identified the type of interaction according to [dv/ (DE50-95) v + dr/ (DE50-95) r] leading to a value less than one [1] indicating additivism. All numerical values actually obtained are in close agreement with that coming from other methods, suggesting that this is an easy, consistent and useful tool for the calculation of the doseresponserelationship in general and for the study of the vecuronium-rocuronium interaction in particular.