Development and validation of sensitive LC-MS/MS assays for quantification of HP-#x03B2;-CD in human plasma and CSF

2-Hydroxypropyl-#x03B2;-cyclodextrin (HP-#x03B2;-CD), a widely used excipient for drug formulation, has emerged as an investigational new drug for the treatment of Niemann-Pick type C1 (NPC1) disease, a neurodegenerative cholesterol storage disorder. Development of a sensitive quantitative LC-MS/MS assay to monitor the pharmacokinetics (PKs) of HP-#x03B2;-CD required for clinical trials has been challenging owing to the dispersity of the HP-#x03B2;-CD. To support a phase 1 clinical trial for ICV delivery of HP-#x03B2;-CD in NPC1 patients, novel methods for quantification of HP-#x03B2;-CD in human plasma and cerebrospinal fluid (CSF) using LC-MS/MS were developed and validated: a 2D-LC-in-source fragmentation-MS/MS (2D-LC-IF-MS/MS) assay and a reversed phase ultra performance LC-MS/MS (RP-UPLC-MS/MS) assay. In both assays, protein precipitation and “dilute and shoot” procedures were used to process plasma and CSF, respectively. The assays were fully validated and in close agreement, and allowed determination of PK parameters for HP-#x03B2;-CD. The LC-MS/MS methods are ∼100-fold more sensitive than the current HPLC assay, and were successfully employed to analyze HP-#x03B2;-CD in human plasma and CSF samples to support the phase 1 clinical trial of HP-#x03B2;-CD in NPC1 patients. 2-Hydroxypropyl-#x03B2;-cyclodextrin (HP-#x03B2;-CD), a widely used excipient for drug formulation, has emerged as an investigational new drug for the treatment of Niemann-Pick type C1 (NPC1) disease, a neurodegenerative cholesterol storage disorder. Development of a sensitive quantitative LC-MS/MS assay to monitor the pharmacokinetics (PKs) of HP-#x03B2;-CD required for clinical trials has been challenging owing to the dispersity of the HP-#x03B2;-CD. To support a phase 1 clinical trial for ICV delivery of HP-#x03B2;-CD in NPC1 patients, novel methods for quantification of HP-#x03B2;-CD in human plasma and cerebrospinal fluid (CSF) using LC-MS/MS were developed and validated: a 2D-LC-in-source fragmentation-MS/MS (2D-LC-IF-MS/MS) assay and a reversed phase ultra performance LC-MS/MS (RP-UPLC-MS/MS) assay. In both assays, protein precipitation and “dilute and shoot” procedures were used to process plasma and CSF, respectively. The assays were fully validated and in close agreement, and allowed determination of PK parameters for HP-#x03B2;-CD. The LC-MS/MS methods are ∼100-fold more sensitive than the current HPLC assay, and were successfully employed to analyze HP-#x03B2;-CD in human plasma and CSF samples to support the phase 1 clinical trial of HP-#x03B2;-CD in NPC1 patients. Cyclodextrins are cyclic oligosaccharides consisting of a varying number of α-1-4-linked glucose units. These glucose chains create a cone-like cavity into which compounds may enter and form a water-soluble complex, thus altering the drug's physicochemical properties. The 2-hydroxypropyl-#x03B2;-cyclodextrin (HP-#x03B2;-CD), a hydroxyalkyl derivative of #x03B2;-cyclodextrin, (Fig. 1A) has been widely utilized as an excipient to improve the solubility of poorly water-soluble drugs and to enhance physicochemical properties and chemical stability of drugs, because of its cavity size and greater hydrophilicity. HP-#x03B2;-CD has also emerged as a promising experimental therapy for Niemann-Pick type C1 (NPC1) disease, a rare inherited neurodegenerative disorder with an estimated incidence in Western European and US populations in the order of one in 100,000 live births (1Vanier M.T. Niemann-Pick disease type C.Orphanet J. Rare Dis. 2010; 5: 16Crossref PubMed Scopus (786) Google Scholar). NPC1 disease is characterized by an accumulation of cholesterol and other lipids in the endosomal/lysosomal system, resulting in hepatosplenomegaly, progressive neurologic dysfunction, and early death (2Vanier M.T. Millat G. Niemann-Pick disease type C.Clin. Genet. 2003; 64: 269-281Crossref PubMed Scopus (489) Google Scholar). Treatment with HP-#x03B2;-CD ameliorates cholesterol storage, significantly reducing neurodegeneration and increasing lifespan in murine and feline models of NPC1 disease (3Liu B. Turley S.D. Burns D.K. Miller A.M. Repa J.J. Dietschy J.M. Reversal of defective lysosomal transport in NPC disease ameliorates liver dysfunction and neurodegeneration in the npc1-/- mouse.Proc. Natl. Acad. Sci. USA. 2009; 106: 2377-2382Crossref PubMed Scopus (314) Google Scholar, 4Davidson C.D. Ali N.F. Micsenyi M.C. Stephney G. Renault S. Dobrenis K. Ory D.S. Vanier M.T. Walkley S.U. Chronic cyclodextrin treatment of murine Niemann-Pick C disease ameliorates neuronal cholesterol and glycosphingolipid storage and disease progression.PLoS ONE. 2009; 4: e6951Crossref PubMed Scopus (354) Google Scholar, 5Liu B. Ramirez C.M. Miller A.M. Repa J.J. Turley S.D. Dietschy J.M. Cyclodextrin overcomes the transport defect in nearly every organ of NPC1 mice leading to excretion of sequestered cholesterol as bile acid.J. Lipid Res. 2010; 51: 933-944Abstract Full Text Full Text PDF PubMed Scopus (137) Google Scholar, 6Ramirez C.M. Liu B. Taylor A.M. Repa J.J. Burns D.K. Weinberg A.G. Turley S.D. Dietschy J.M. Weekly cyclodextrin administration normalizes cholesterol metabolism in nearly every organ of the Niemann-Pick type C1 mouse and markedly prolongs life.Pediatr. Res. 2010; 68: 309-315Crossref PubMed Scopus (130) Google Scholar, 7Ward S. O'Donnell P. Fernandez S. Vite C.H. 2-hydroxypropyl-beta-cyclodextrin raises hearing threshold in normal cats and in cats with Niemann-Pick type C disease.Pediatr. Res. 2010; 68: 52-56Crossref PubMed Scopus (92) Google Scholar). Based on these studies, individual use investigational new drug applications for HP-#x03B2;-CD have been allowed for eight pediatric patients in the US, and a phase 1 trial for delivery of HP-#x03B2;-CD directly into the lateral ventricle of NPC1 patients was initiated in January 2013 at the National Institutes of Health (NIH) (8Ottinger E.A. Kao M.L. Carrillo-Carrasco N. Yanjanin N. Shankar R.K. Janssen M. Brewster M. Scott I. Xu X. Cradock J. et al.Collaborative development of 2-hydroxypropyl-beta-cyclodextrin for the treatment of Niemann-Pick type C1 disease.Curr. Top. Med. Chem. 2014; 14: 330-339Crossref PubMed Scopus (95) Google Scholar). To support the clinical trial, a reliable assay capable of quantifying HP-#x03B2;-CD in human plasma and cerebrospinal fluid (CSF) was essential. The only bioanalytical assay that has been reported for HP-#x03B2;-CD quantification in human samples involves HPLC using inclusion complex formation and fluorescence detection. A limitation of this assay is the minimum requirement for 1 ml of plasma or urine to reach a lower limit of quantification (LLOQ) of 0.5 #x03BC;g/ml (9Szathmary S.C. Determination of hydroxypropyl-beta-cyclodextrin in plasma and urine by size-exclusion chromatography with post-column complexation.J. Chromatogr. 1989; 487: 99-105Crossref PubMed Scopus (22) Google Scholar). To address the need for a sensitive assay to determine the pharmacokinetics (PKs) of HP-#x03B2;-CD in the context of a clinical trial, we initially developed and validated a novel method utilizing 2D-LC-in-source fragmentation-MS/MS (2D-LC-IF-MS/MS) for sensitivity enhancement with LLOQ for HP-#x03B2;-CD of 10 ng/ml in human plasma and 100 ng/ml for HP-#x03B2;-CD in human CSF, respectively. A more streamlined alternative approach was subsequently developed and validated according to generally accepted regulatory guidances (10.US Department of Health and Human Services Food and Drug Administration. 2001. Guidance for Industry: Bioanalytical Method Validations. Center for Drug Evaluation and Research, Center for Veterinary Medicine. Accessed June 5, 2014, at http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM368107.pdf.Google Scholar, 11Viswanathan C.T. Bansal S. Booth B. DeStefano A.J. Rose M.J. Sailstad J. Shah V.P. Skelly J.P. Swann P.G. Weiner R. Quantitative bioanalytical methods validation and implementation: best practices for chromatographic and ligand binding assays.Pharm. Res. 2007; 24: 1962-1973Crossref PubMed Scopus (614) Google Scholar, 12.European Medicines Agency (EMA). 2011. Guideline on Bioanalyti­cal Method Validation. Accessed June 5, 2014, at http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2011/08/WC500109686.pdf.Google Scholar) to support analysis of samples from the phase 1 trial. The latter assay uses a reversed phase ultra performance liquid chromatography (RP-UPLC)-MS/MS method for quantitative determination of HP-#x03B2;-CD in human plasma and CSF with LLOQs at 50.0 ng/ml and 5.00 #x03BC;g/ml, respectively. We found both assays were robust and reliable. While the 2D-LC-IF-MS/MS method was more sensitive and provided a more complete HP-#x03B2;-CD PK profile, as many postdose plasma samples in clinical study were below the LLOQ of the RP-UPLC-MS/MS method, the RP-UPLC-MS/MS method proved easier to implement and afforded more rapid sample analysis. Herein, we report the development and validation of both assays. The HP-#x03B2;-CD was obtained from Janssen Research and Development (Beerse, Belgium). #x03B2;-Cyclodextrin, sodium hydroxide, ammonium formate, and ammonium carbonate were purchased from Sigma-Aldrich (St. Louis, MO). The d6-propylene oxide was purchased from Polymer Source (Dorval, Montreal, Quebec, Canada). Triethylamine, acetone, methanol, acetonitrile, and formic acid were purchased from EMD Chemicals (Gibbstown, NJ). Methanol was also purchased from Merck (Darmstadt, Germany). Acetonitrile was also purchased from Biosolv (Valkenswaard, The Netherlands). Milli-Q ultrapure water was prepared in-house with a Milli-Q integral water purification system (Billerica, MA). Pooled control human plasma (Na-heparin), human CSF, six lots of individual human plasma, and six lots of individual human CSF were purchased from BioChemed Services (Winchester, VA) or Bioreclamation (Westbury, NY). 1 was in in The was to and d6-propylene oxide was with a MA). of the was at and with formic The was with phase on a in to of which on cyclodextrin as by (Fig. A of 1 in water and oxide was to for 1 and to for The was to The was and in was which on cyclodextrin as by as as a in the form of (Fig. The HP-#x03B2;-CD and were and in water to a for HP-#x03B2;-CD were prepared and the the was was used for and the other was used for control These were at The were prepared by with The ng/ml and #x03BC;g/ml in the 2D-LC-IF-MS/MS method for the human plasma and CSF assays, ng/ml and #x03BC;g/ml in the RP-UPLC-MS/MS method for the human plasma and CSF assays, and and samples were prepared by HP-#x03B2;-CD was into the and in plasma and CSF were in at or and and for HP-#x03B2;-CD in human plasma and human CSF in a new and of samples for HP-#x03B2;-CD in human plasma and CSF in a new the plasma assay, to of plasma of #x03BC;g/ml in water in the 2D-LC-IF-MS/MS method or of #x03BC;g/ml in water in the RP-UPLC-MS/MS was for the in which water in the 2D-LC-IF-MS/MS method and in the RP-UPLC-MS/MS was by and in the 2D-LC-IF-MS/MS method and the RP-UPLC-MS/MS method, The were and The were to and to a of The was with of the CSF assay in the 2D-LC-IF-MS/MS method, of CSF sample was with 100 of #x03BC;g/ml in and the was with 100 of In the RP-UPLC-MS/MS method, of CSF sample was with of and 100 of the sample was with of #x03BC;g/ml in for the in which of water was and to these samples 100 water was and eight in for the 2D-LC-IF-MS/MS method, in for the RP-UPLC-MS/MS method, and six of samples at the of and one and one with were in The plasma samples with a the and sample were or with plasma to The CSF samples with the and sample were or with water or CSF to A and an with in were used in the 2D-LC-IF-MS/MS method and the RP-UPLC-MS/MS method, respectively. In the 2D-LC-IF-MS/MS method, the and were used for HP-#x03B2;-CD and with a of 100 for The were used in the RP-UPLC-MS/MS method for and with a of for of the and The was at for both the and The parameters are in 1 in a new 1 A HPLC system with a system a a and were used to HP-#x03B2;-CD and from the The chromatography was at using a and liquid chromatography as and respectively. The of the was at is a of the and for the phase A ammonium and formic acid in and phase formic acid in were with a as and at a of The for using 10 ammonium and formic acid in and at a of was as and The 1 from A to at and to A at The from A to at and to A at The system was an consisting of and sample The were using an 100 at The were with a at a of with an of 10 for plasma and for The phase was of phase A ammonium carbonate in and phase The was as and B. clinical study was by the of the National of Health and Human from and were obtained from The study was on and use of HP-#x03B2;-CD was investigational new drug NPC1 were to the Center and an was on the The HP-#x03B2;-CD was prepared in ml of an and HP-#x03B2;-CD were ICV the CSF and and ml were at and and PK parameters of HP-#x03B2;-CD for CSF and plasma were with the approach using Louis, MO). the the was using the the of the phase was estimated by using at and the was from the was estimated as the of the is the of the and The was as the CSF the of HP-#x03B2;-CD was as and the of at was as is the the from to the plasma the of HP-#x03B2;-CD was by the drug to reach and HP-#x03B2;-CD is a complex of and in which are a number of at of the and quantitative of the as a was to the dispersity of the that are a number of and In are and in the HP-#x03B2;-CD on of in of and the of the J. cyclodextrin and in Drug PubMed Scopus Google Scholar). In order to HP-#x03B2;-CD with to developed and approach was of the HP-#x03B2;-CD and into was to determine one used as a for the quantification of the of the HP-#x03B2;-CD phase have a on HP-#x03B2;-CD in to in the of formic HP-#x03B2;-CD sodium and a of that were used for in In the phase of of 2D-LC-IF-MS/MS of ammonium and of formic acid as in and were the were from of from ammonium In the phase of the RP-UPLC-MS/MS method ammonium carbonate as in phase ammonium were The number of from to in the of the of 2D-LC-IF-MS/MS (Fig. and one to in the phase of the RP-UPLC-MS/MS method (Fig. the HP-#x03B2;-CD with the as in is a complex of a number of The of formation for these is leading to a in the of HP-#x03B2;-CD in were in the were for to and were employed as for detection. the is significantly in the the sample and in an the this may with or is or has been used in J. on as by with PubMed Scopus Google J. K. K. phase liquid chromatography to of chemical for and of and Chromatogr. Sci. 2009; PubMed Scopus Google Scholar, J. of using for 2010; PubMed Scopus Google Scholar, B. E.A. S. of of and of the by liquid PubMed Scopus Google C.M. method development for drug metabolism in Chromatogr. Sci. PubMed Scopus Google and Rose M.J. M. quantitative analysis of a human in using and PubMed Scopus Google Scholar). of which was by increasing on a to and of the HP-#x03B2;-CD and The (Fig. and the complex of and was to of HP-#x03B2;-CD. The was a the for and was as a for HP-#x03B2;-CD and as the for The of the of the was on its (Fig. The and of the The at a was for the and and were for of HP-#x03B2;-CD and the respectively. an alternative approach in the RP-UPLC-MS/MS method, individual HP-#x03B2;-CD of the of were in Method development that of the individual was for the of HP-#x03B2;-CD and provided as using the approach or fluorescence on that the of is used for the as for in the HP-#x03B2;-CD was as a in as this is the in the provided the best sensitivity in The and were for of HP-#x03B2;-CD and the respectively. HP-#x03B2;-CD is water and poorly in was for sample A protein precipitation method was developed to the phase method used for plasma (9Szathmary S.C. Determination of hydroxypropyl-beta-cyclodextrin in plasma and urine by size-exclusion chromatography with post-column complexation.J. Chromatogr. 1989; 487: 99-105Crossref PubMed Scopus (22) Google Scholar) to its and plasma samples in the 2D-LC-IF-MS/MS and RP-UPLC-MS/MS protein precipitation with was by of the and of the in The the of the and as of the the of the The CSF samples were with in water and to 2D-LC-IF-MS/MS assay directly or to RP-UPLC-MS/MS assay with water and of We found that HP-#x03B2;-CD was as a in on an of is sensitivity with to the phase of HP-#x03B2;-CD in plasma samples prepared with protein precipitation was by was used the in plasma that to C.M. method development for drug metabolism in Chromatogr. Sci. PubMed Scopus Google are from HP-#x03B2;-CD on the that other as and may for the of reversed phase and has been successfully used to and sensitivity for compounds with and chromatography on with phase for of compounds in PubMed Scopus Google Scholar, J. of an chromatographic approach for analysis in plasma by Chromatogr. Sci. 2009; PubMed Scopus Google Scholar). A method was developed to HP-#x03B2;-CD from the using chromatographic of samples in water allowed of HP-#x03B2;-CD on a reversed phase was A from to phase was used at a of to the of The was the of the HP-#x03B2;-CD on the reversed phase and the HP-#x03B2;-CD was in a from the reversed phase to the which the HP-#x03B2;-CD from other by has been found to sensitive to of the sample from the reversed phase to the was to the and thus and of HP-#x03B2;-CD on The was by a 1 ml the and with phase for the The on the was for 1 a that the was and The was HP-#x03B2;-CD was as a on the size-exclusion chromatographic (9Szathmary S.C. Determination of hydroxypropyl-beta-cyclodextrin in plasma and urine by size-exclusion chromatography with post-column complexation.J. Chromatogr. 1989; 487: 99-105Crossref PubMed Scopus (22) Google the phase used in the size-exclusion chromatography was for sensitivity on LC-MS/MS as a and on reversed phase HPLC owing to and HP-#x03B2;-CD with the number of were as a a using The uses as and these for a with and are which to a a was with this and were The assay of the 2D-LC-IF-MS/MS method was ng/ml for human plasma and #x03BC;g/ml for human the an of with of than of for human plasma, of to with of than for human The was for human plasma and for human the RP-UPLC-MS/MS method, the assay was ng/ml for human plasma and #x03BC;g/ml for human the an of to with of than for human plasma, and an of to with of than for human The was for human plasma and for human lots of human plasma or human CSF were as In both the 2D-LC-IF-MS/MS and RP-UPLC-MS/MS assays, were in the at the of and from The with to the (Fig. The LLOQ samples of the assays in human plasma ng/ml for the RP-UPLC-MS/MS method and 10 ng/ml for the 2D-LC-IF-MS/MS and CSF #x03BC;g/ml for the RP-UPLC-MS/MS method and #x03BC;g/ml for the 2D-LC-IF-MS/MS were in of human plasma and of human CSF, respectively. LLOQ was as the that with and than or to of and at LLOQ were the for the at the LLOQ are in The and of the method were by six of samples at and in A of the and assay and of individual for human plasma and CSF is in the was and the was in the of in the and of for human plasma and of with a of for human plasma and of to with a of for human CSF were obtained for the 2D-LC-IF-MS/MS the RP-UPLC-MS/MS method, an of with a of for human plasma and an of with a of for human CSF were The to of HP-#x03B2;-CD and its or from plasma was by the of the samples to the samples at and The of HP-#x03B2;-CD and was for plasma and was for were in the of for the 2D-LC-IF-MS/MS method and for the RP-UPLC-MS/MS method in the human plasma and human CSF assays. The were close to 1 for both that the were by the was also in The stability of HP-#x03B2;-CD to in human plasma and CSF, at at for human plasma and for and at for human plasma and for were sample stability at and at was for for plasma and for for CSF stability of HP-#x03B2;-CD and in water was for at for 1 at and for at for both methods was found to of the of the in the of the assays. The assays were validated to successfully analyze of the 2D-LC-IF-MS/MS and methods were used to analyze HP-#x03B2;-CD in human plasma and CSF samples obtained from were of HP-#x03B2;-CD ICV in a phase 1 study of HP-#x03B2;-CD in NPC1 the 2D-LC-IF-MS/MS method, of CSF samples postdose were the LLOQ of #x03BC;g/ml, and of plasma samples postdose were the LLOQ of 10 and of the CSF and plasma respectively. using the method, only of CSF and of plasma postdose samples were the assay human plasma and CSF samples were by both and the obtained by both methods were in close with of and for plasma and CSF, (Fig. PK were for HP-#x03B2;-CD in CSF and plasma in the patients with HP-#x03B2;-CD ICV (Fig. The CSF and plasma by both methods were used in the PK in the CSF PK parameters were for parameters for the in which a of was the assay A was obtained on the CSF by to the that this method a the drug in CSF were to the of (Fig. the ICV of CSF of HP-#x03B2;-CD were with the from to #x03BC;g/ml in patients The of was lower than the CSF of in normal human of cerebrospinal fluid new in and Res. 5: PubMed Scopus Google Scholar). The of ml was to the reported CSF in The estimated for HP-#x03B2;-CD in CSF was on the RP-UPLC-MS/MS method and on the 2D-LC-IF-MS/MS PK parameters of HP-#x03B2;-CD in patients ICV with of for for for for was on of by 2D-LC-IF-MS/MS and RP-UPLC-MS/MS for in a new PK was on of by 2D-LC-IF-MS/MS and RP-UPLC-MS/MS respectively. to the CSF the plasma PK parameters were using the by these assay methods ICV HP-#x03B2;-CD into the the plasma of HP-#x03B2;-CD was lower than in The and of HP-#x03B2;-CD in plasma were than of the CSF PK a was obtained from the 2D-LC-IF-MS/MS method, to the that this method a sensitivity and plasma drug were to the of The estimated for HP-#x03B2;-CD in plasma were on the RP-UPLC-MS/MS method and on the 2D-LC-IF-MS/MS PK parameters of HP-#x03B2;-CD in patients with of HP-#x03B2;-CD PK was on of by 2D-LC-IF-MS/MS and RP-UPLC-MS/MS methods was on of by 2D-LC-IF-MS/MS and RP-UPLC-MS/MS respectively. in a new PK was on of by 2D-LC-IF-MS/MS and RP-UPLC-MS/MS respectively. HP-#x03B2;-CD has emerged as a promising therapy for NPC1 A phase 1 trial is at the Center to the of HP-#x03B2;-CD to NPC1 patients. To support this clinical trial, novel assays for the quantification of HP-#x03B2;-CD were developed and methods the by the of the HP-#x03B2;-CD and that are to more sensitive than the method (9Szathmary S.C. Determination of hydroxypropyl-beta-cyclodextrin in plasma and urine by size-exclusion chromatography with post-column complexation.J. Chromatogr. 1989; 487: 99-105Crossref PubMed Scopus (22) Google Scholar). The of assays to and HP-#x03B2;-CD in CSF and plasma only in drug for treatment of NPC1 disease, also for the of HP-#x03B2;-CD in other as and disease, in which HP-#x03B2;-CD is as a J. M.T. by cyclodextrin in and mouse models of Med. PubMed Scopus Google Scholar). The current for HP-#x03B2;-CD quantification is on an HPLC method with fluorescence of inclusion (9Szathmary S.C. Determination of hydroxypropyl-beta-cyclodextrin in plasma and urine by size-exclusion chromatography with post-column complexation.J. Chromatogr. 1989; 487: 99-105Crossref PubMed Scopus (22) Google Scholar). of this method are the requirement for sample and of which its in the current PK study of HP-#x03B2;-CD in the plasma samples are below the LLOQ of the HPLC To these we have and sensitive 2D-LC-IF-MS/MS and RP-UPLC-MS/MS methods only a sample and rapid sample with the 2D-LC-IF-MS/MS method, the RP-UPLC-MS/MS method is and easier to of HP-#x03B2;-CD the as in clinical or The on the other proved more sensitive for quantification of HP-#x03B2;-CD in the plasma and CSF The of the latter HP-#x03B2;-CD assay is the of and the and the method are more complex, the system on reversed phase liquid chromatography and the of HP-#x03B2;-CD from and The sensitivity and limit by of samples in water chromatographic and with of as an in and sensitivity to a of in the The HP-#x03B2;-CD are a number of and reducing the of quantification only one is as for the HP-#x03B2;-CD and into and the by with the are The for HP-#x03B2;-CD at that a and at with was to is only sensitive also in the of or the methods in the which a protein precipitation sample have a than the reported method (9Szathmary S.C. Determination of hydroxypropyl-beta-cyclodextrin in plasma and urine by size-exclusion chromatography with post-column complexation.J. Chromatogr. 1989; 487: 99-105Crossref PubMed Scopus (22) Google Scholar). assays were developed for human plasma and CSF to the PK study of HP-#x03B2;-CD in a human phase 1 trial in the NPC1 patients. obtained from this study were used to on the and of HP-#x03B2;-CD administration an to patients with The sensitivity of the 2D-LC-IF-MS/MS and RP-UPLC-MS/MS assays for a of HP-#x03B2;-CD in human plasma and CSF samples from the phase 1 trial. LLOQ of 10 ng/ml in human plasma with 2D-LC-IF-MS/MS method is for of drug that the drug is to the of ICV administration of HP-#x03B2;-CD to human PK parameters from the from both assays were that a was obtained from the 2D-LC-IF-MS/MS method to its In this we and 2D-LC-IF-MS/MS and RP-UPLC-MS/MS methods that have been developed and validated for quantitative determination of HP-#x03B2;-CD in human plasma and The is and involves a one protein precipitation for plasma and with water for methods were used to HP-#x03B2;-CD in human plasma and CSF ICV While the 2D-LC-IF-MS/MS method was more the RP-UPLC-MS/MS method was easier to implement and more methods a methods for quantification of and are for clinical with ICV

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.