High-performance liquid chromatographic method for the routine determination of diclofenac and its hydroxy and methoxy metabolites from in vitro systems

Schmitz, G.; Lepper, Hans; Estler, C.‐J.

doi:10.1016/0378-4347(93)80065-c

Cited by 25 publications

(12 citation statements)

References 18 publications

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“…Further, potential presence of 3 -hydroxy-diclofenac, the minor monohydroxy-metabolite of DF, in the mouse samples will probably not be noticed due to insufficient resolution. Liquid chromatographic separation between 3 -hydroxy-diclofenac and 4 -DF was not expected in our assay because it was shown to be very difficult to separate them resulting in only poor resolution using long columns and long run times [11,15,16,23] or in no separation at all [14].…”

Section: Mass Spectrometrymentioning

confidence: 88%

Liquid chromatography–tandem mass spectrometric assay for diclofenac and three primary metabolites in mouse plasma

Sparidans

Lagas

Schinkel

et al. 2008

Journal of Chromatography B

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Section: Mass Spectrometrymentioning

confidence: 88%

Liquid chromatography–tandem mass spectrometric assay for diclofenac and three primary metabolites in mouse plasma

Sparidans

Lagas

Schinkel

et al. 2008

Journal of Chromatography B

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“…The model assays were carried out as described previously [Phenacetin O-deethylase assay [26], Diclofenac 4′-hydroxylase assay [27], Bufuralol 1′-hydroxylase assay [28] and Testosterone 6β-hydroxylase assay [29]. Briefly, test compounds were added from stock solutions at 10 μM in the incubation mixture in a small volume of DMSO.…”

Section: Plasma Protein Binding Assaymentioning

confidence: 99%

Pharmacological evaluation of C-3 modified Betulinic acid derivatives with potent anticancer activity

et al. 2007

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In vitro and in vivo pharmacological screening of Betulinic acid (BA) and five dihydro-BA derivatives modified at C-3 position [4-nitrobenzyl-oximino (1), 2-4-difluoro-benzoyloxy (2), 2-4-difluoro-benzylidene-amino (3), benzoyl-hydrazono (4), and 4-fluorophenyl-hydrazono (5)], having potent in vitro anti-cancer activity was carried out using ADME, animal PK and tumor studies. We found that BA and the derivatives had poor aqueous solubility (<0.1 microg/ml), low to moderate permeability (log Pe<-5.0) and high plasma protein binding (>70%). Although BA and 5 were metabolized by human liver microsomes, derivatives 1, 2, 3 and 4 possessed good in vitro metabolic stability. Except 3 which inhibited CYP1A2 isoform by more than 50% none of the other compounds inhibited key cytochrome P450 enzyme isoforms (CYP1A2, CYP2C9, CYP2D6 and CYP3A4) at 10 microM. Based on in vitro results one derivative 1 was tested in rodent PK and tumor studies. We found that 1 exhibited favorable pharmacokinetic characteristics of a systemically administered drug and showed better in vivo anti-tumor efficacy as compared to BA in a human colon cancer xenograft model. Our results show that BA derivatives are potential anti-cancer compounds which need to be explored in detail.

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“…Since skin probably lacks the ability to form conjugates, the metabolites we might expect would be the products of hydroxylation only. HPLC is a versatile method to separate diclofenac and authentic metabolites (14)(15)(16)(17). In this study, HPLC was optimized to provide sufficient intervals between retention times of the parent compound diclofenac and its authentic metabolites.…”

Section: Discussion Conclusionmentioning

confidence: 99%

Diclofenac metabolic profile followingin vitro percutaneous absorption through viable human skin

Tanojo

Wester

Shainhouse

et al. 1999

Eur. J. Drug Metab. Pharmacokinet.

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The extent of metabolism of diclofenac sodium in excised viable human skin was investigated using combination HPLC and radioactivity assay. In an earlier diffusion experiment using an in vitro flow-through diffusion system, radiolabelled diclofenac sodium in either lotion (Pennsaid) or aqueous solution was applied to viable human skin, either as single dose or multiple dose (8 times over 2 days). In this study, the receptor fluid samples from the diffusion experiment were subjected to extraction and the aliquot was analysed using HPLC to separate diclofenac and authentic metabolites. Based on the radioactivity of each HPLC fraction, the collection time of the fractions was compared with the retention time of diclofenac and metabolites in standard solutions. The samples from a single or multiple dose application of lotion showed radioactivity in mainly one fraction, whose retention time corresponded with diclofenac. Other HPLC fractions showed none or only small amounts of radioactivity within the error range of the assay. The same results were obtained with the pooled samples from the application of the lotion or of aqueous solution. The results suggest that diclofenac sodium does not undergo metabolism in viable human epidermis during percutaneous absorption in vitro. Hence, with topical application to human skin in vivo, diclofenac will be delivered with minimal, if any, metabolism.

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High-performance liquid chromatographic method for the routine determination of diclofenac and its hydroxy and methoxy metabolites from in vitro systems

Cited by 25 publications

References 18 publications

Liquid chromatography–tandem mass spectrometric assay for diclofenac and three primary metabolites in mouse plasma

Liquid chromatography–tandem mass spectrometric assay for diclofenac and three primary metabolites in mouse plasma

Pharmacological evaluation of C-3 modified Betulinic acid derivatives with potent anticancer activity

Diclofenac metabolic profile followingin vitro percutaneous absorption through viable human skin

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