HPLC assay for determination of amphotericin B in biological samples

Transcription

1 BIOMEDICAL CHROMATOGRAPHY Biomed. Chromtogr. 22: (2008) Published 402 online ORIGINAL 5 December RESEARCH 2007 in Wiley InterScience ORIGINAL RESEARCH R. Espd et l. ( HPLC ssy for determintion of mphotericin B in biologicl smples R. Espd, 1 J. M. Jos, 2 S. Vldespin, 1 M. A. De, 3 M. P. Bllesteros, 1 J. M. Alund 4 nd J. J. Torrdo 1 * 1 Deprtment of Phrmcy nd Phrmceuticl Technology, Fculty of Phrmcy, Complutense University, Mdrid, Spin 2 Lvetp Veterinry Clinic, Benito Gutierrez 26, Mdrid, Spin 3 Deprtment of Prsitology, Fculty of Phrmcy, Complutense University, Mdrid, Spin 4 Deprtment of Animl Helth, Fculty of Veterinry Medicine, Complutense University, Mdrid, Spin Received 19 June 2007; revised 13 September 2007; ccepted 14 September 2007 ABSTRACT: A fst nd selective HPLC method for ssying mphotericin B in biologicl smples ws developed nd vlidted. The chromtogrphic seprtion ws chieved in less thn 12 min on reverse-phse C 18 column using n cetonitrile cetic cid wter (52:4.3:43.7, v/v/v) mixture s mobile phse. The flow rte ws 1 ml/min nd the effluent ws monitored t 406 nm. A liner response over the concentrtion rnge μg/ml ws obtined. Intr-dy nd inter-dy RSDs were below 5% for ll the smple types. This new HPLC method ws pplied to ssy mphotericin B in plsm nd severl tissue smples such s kidney, liver, spleen nd bone mrrow. Appliction of this method to phrmcokinetic studies in mice nd dog is provided. Copyright 2007 John Wiley & Sons, Ltd. KEYWORDS: mphotericin B; high-pressure liquid chromtogrphy; vlidtion; phrmcokinetics INTRODUCTION The polyene ntibiotic mphotericin B (AB), produced by Streptomyces nodosus, is one of the mcrocylic compounds contining both crboxyl nd mino groups. AB hs n mphiptic chrcter due to the rigid lipophilic chin of seven conjugted double bonds on one side of the mcrolide ring nd the hydroxyl groups on the opposite side, nd this chrcteristic structure is believed to be importnt in its biologicl ction. AB remins the reference tretment for invsive fungl infections such s cndidisis, coccidiosis, criptococosis, histoplsmosis nd spergillosis (Brrett et l., 2003; Gllis et l., 1990), s well s for the tretment of leishmnisis (Brrt et l., 2005; Murry, 2004; Olliro et l., 2005). However, the use of AB s mixed-micellr dispersion with sodium deoxycholte (Fungizone, Bristol- Myers Squibb, USA) is limited by toxicity, with both infusion-relted effects nd cumultive nephrotoxicity. To reduce this toxicity, severl lipid-bsed formultions *Correspondence to: J. J. Torrdo Durán, Fcultd de Frmci. Universidd Complutense, Plz Rmón y Cjl s/n, Mdrid, Spin. E-mil: torrdo1@frm.ucm.es Abbrevitions used: AB, mphotericin B. Contrct/grnt sponsor: Complutense University nd Mdrid Community Administrtion; Contrct/grnt number: Contrct/grnt sponsor: Science nd Technology Interministeril Commission, Government of Spin; Contrct/grnt number: AGL GAN. of AB hve been developed, such s liposoml formultion (AmBisome, Nextr Phrmceuticls, USA), lipid complex of AB with phospholipids (Abelcet, Liposome Compny Inc., USA) nd colloidl dispersion of AB with cholestryl sulfte (Amphocil, Sequus Phrmceuticls Inc., USA), nd these re now vilble in severl countries (Tiphine et l., 1999). Although ech of these novel products hs its own phrmceuticl composition nd phrmcokinetics, there is still only limited dt bout their optiml therpeutic dosges nd disposition kinetics, so it is very importnt to be ble to control levels in plsm nd ll medi where new AB formultions (like liposomes, complexes, nnoprticles or colloidl pstes) re ssyed. Therefore, there hs been much interest in developing fst nd relible mesurements of AB plsm, whole blood nd tissue concentrtions using vlidted ssys. With this im, different methods hve been described in order to nlyze biologicl smples contining AB. For instnce, there re complex HPLC methods tht cn seprte free AB, protein-bound AB nd lipidformulted AB in plsm (Egger et l., 2001; Bekersky et l., 2002). Although some phrmcopoeis recommend the use of microbiologicl ssys for quntittive determintion of AB (The United Sttes Phrmcopei, 2006), HPLC methods hve been demonstrted to be esier, fster, nd more ccurte nd reproducible. The purpose of the present work ws to develop fst nd relible HPLC method for quntittion of AB in different biologicl smples tht could be performed Copyright 2007 John Wiley & Sons, Ltd. Biomed. Chromtogr. 22: (2008)

2 HPLC ssy for determintion of mphotericin B in biologicl smples ORIGINAL RESEARCH 403 esily in reserch nd routine clinicl lbortories with currently vilble equipment nd mterils. Most of HPLC methods for AB quntifiction reported in the literture used slts in their mobile phse (Alk et l., 1996; Eldem nd Aricn-Cellt, 2001; Egger et l., 2001; Hosotsubo nd Hosotsubo, 1989). Slts significntly increse the risk of sturtion, brekdown or overpressure in the column nd reduce the life-time of the column. Although some other HPLC methods without slts in their mobile phse hve been reported (Echevrrí et l., 1998; Lue et l., 2002), in our experimentl conditions with those methods it ws not possible to obtin correct seprtion for AB. Therefore, new HPLC method for monitoring AB in queous/methnol mediums suitble for ssy of biologicl smples hs been developed nd is described nd vlidted. EXPERIMENTAL Mterils AB rw mteril ws gift from Squibb Bristol Myers, Brcelon, Spin. HPLC-grde cetonitrile nd methnol (MeOH) were purchsed from Lbscn, Dublin, Irelnd. Acetic cid ws supplied by Pnrec S.A., Brcelon, Spin. Sodium hydroxide ws provided by Pnrec S.A., Brcelon, Spin. Deionized wter ws obtined from Milli-Q wter purifiction system (Millipore, USA). Apprtus nd chromtogrphic conditions High-performnce liquid chromtogrphy ws performed with modulr liquid chromtogrph equipped with Jsco PU-1580 pump, Gilson 231 XL utosmpler fitted to 100 μl smpling loop nd Jsco UV-1575 UV visible detector. Integrtion of the peks ws performed with the progrm Borwin 1.5 for PC (JMBS Developments). Compounds were seprted on mm, 5 μm prticle size Thermo Hypersil BDS C 18 reverse-phse column. Elution ws crried out isocrticlly with mobile phse consisted of n cetonitrile cetic cid wter (52:4.3:43.7, v/v/v) mixture filtered through 0.45 μm hydrophilic polypropylene filter membrne (GH polypro, Pll Corp., USA) nd degssed. It flowed t constnt flow rte of 1 ml/min nd the effluent ws monitored t 406 nm. The totl chromtogrphic run time ws 15 min. Under these conditions, the reltive retention time of AB ws pproximtely 12 min. Stndrd solutions Stock solutions were prepred by ccurtely weighing 15 mg of AB in 100 ml volumetric flsk, dissolved nd diluted to volume with ph 11 sodium hydroxide queous medium, to obtin concentrtion of 150 μg/ml. Stock solutions were further diluted with n MeOH:H 2 O (2:1, v/v) mixture to obtin the following clibrtion stndrds: 0.1, 0.3, 1, 3 nd 10 μg/ml; ll these clibrtion stndrds, obtined from ech stock solution, were nlyzed in triplicte. Vlidtion of the ssy Linerity. The linerity ws evluted with diluted stock stndrd solutions contining 0.1, 0.3, 1, 3 nd 10 μg/ml of AB. For ech concentrtion three mesurements were performed nd clibrtion lines were constructed. The dt were sttisticlly evluted using regression nlysis softwre pckge (Sttgrphics Plus 5.0, Mnugistics, USA) nd the equtions were djusted by mens of lest-squre liner regression nlysis. The slope, intercept nd determintion coefficients of ech clibrtion line together with the men nd stndrd devition (SD) were determined. Accurcy. The recoveries of AB were determined by spiking n mount of the drug into blnk MeOH:H 2 O (2:1, v/v), plsm nd tissue (liver, spleen nd kidney) smples respectively. Recoveries were evluted by nlyzing smples t the following concentrtions: 0.1, 3 nd 10 μg/ml. Plsm smples were prepred by mixing four prts of blnk plsm, obtined from humn volunteers, nd one prt of MeOH:H 2 O (2:1 v/v) smples contining different known concentrtions of AB. In this wy, AB plsm:meoh (4:1 v/v) smples of 0.1, 3 nd 10 μg/ml were obtined nd then they were deproteinted with 2 vols of MeOH. All these smples were vortexed for 1 min nd centrifuged t 4500 rpm for 10 min. Superntnt ws filtered through 0.45 μm sterile syringe filter (Millex, Millipore Millex HV-1) nd injected into the HPLC. Tissue smples were obtined from mice. Mice were scrificed by chloroform inhltion, nd the liver, spleen nd kidneys were sonicted in wter, nd four prts of MeOH:H 2 O (2:1) contining different known mounts of AB, in order to obtin AB concentrtions of 0.1, 3 nd 10 μg/ml, were dded to one prt of the homogente. The resulting mixtures obtined from liver, spleen nd kidneys were vortexed for 1 min nd centrifuged t 4500 rpm for 10 min. Superntnts were filtered through 0.45 μm sterile syringe filter (Millex, Millipore Millex HV-1) nd injected into the HPLC. The individul nd the overll men percentge recovery were clculted nd reltive stndrd devition (RSD) vlue of mximum 5% ws set s the cceptnce criterion. Intrdy nd inter-dy precision. Intrdy precision ws defined s RSD for the pek res clculted from three smples t concentrtions of 0.1, 3 nd 10 μg/ml, respectively, on the sme dy (n = 3). Inter-dy precision ws clculted using the vlues mesured from nine different smples (three smples from ech different dy) t the concentrtions of 0.1, 0.3, 1, 3 nd 10 μg/ ml, respectively. The coefficient of vrition for the pek res ws clculted. Sensitivity. The sensitivity in terms of detection nd quntittion limits ws determined bsed on signl-to-noise rtio, by compring mesuring signls from smples with 0.1 μg/ml of AB with those of blnk smples. Signl-to-noise rtios of 3 nd 10 were considered cceptble for estimting the detection limit nd quntittion limit respectively (ICH, 1996). Selectivity. The selectivity of the HPLC method ws checked by nlyzing different independent blnk humn

3 404 ORIGINAL RESEARCH R. Espd et l. plsm smples. The chromtogrms of the blnk plsm smples were compred with the chromtogrms obtined by plsm spiked with AB. Appliction of the method to phrmcokinetic nd tissue distribution studies As n exmple, the proposed HPLC method ws pplied to determine the plsm concentrtion time profiles of AB following intrvenous bolus dministrtion of new AB formultion, consisting of lbumin microspheres contining AB (AB-Mic) elborted by spry-drying process (Sánchez- Brunete et l., 2004), in dog nd mice. AB-Mic ws prepred by dispersing of AMB in 5 ml of wter solution formed by sodium deoxycholte, dibsic sodium phosphte nd monobsic sodium phosphte. The resulting dispersion ws subjected to moderte stirring to chieve homogeneous suspension. A 20% serum lbumin solution (5 ml) ws dded, nd the finl mixture ws spry-dried using Büchi B 191 spry-drier to obtin lbumin microspheres contining AMB. Femle lbino ICR mice (25 30 g) were housed in groups of six in plstic cges in 12 h drk light cycle niml fcility with controlled temperture (25 C) nd humidity (70%); wter nd food were unrestricted throughout the study. The preprtion ws dministered by intrcrdic injection t dose of 2 mg of AB per kg (body weight). Immeditely before intrcrdic dministrtion, the preprtion ws reconstituted with sterile 5% dextrose in wter. AB concentrtions in serum nd orgns were determined using high-pressure liquid chromtogrphy. Blood smples were obtined by the retroorbitl route t 5 nd 90 min, 6, 18 nd 40 h fter drug injection; plsm ws seprted by centrifugtion (10,000 rpm 10 min) nd AB ws extrcted from plsm in MeOH. Mice were then scrificed by chloroform inhltion, nd the liver, spleen nd kidneys were removed nd homogenized with MeOH. Three mice were used for ech time point. A single dose of 5 mg of AB per kg (body weight) ws dministered intrvenously in dog. Blood smples from the dog were tken t 15, 30, 50, 110 nd 1380 min fter the dministrtion, nd collected in heprinized tubes. The plsm ws seprted by centrifugtion (10,000 rpm for 10 min). Also, bone mrrow smple ws tken t the end of the study. All biologicl specimens were stored t 20 C until nlysis; under these conditions AB ws found to be stble in these biologicl mtrices. RESULTS AND DISCUSSION Vlidtion Chromtogrms of blnk plsm nd AB-spiked queous nd plsm smples re shown in Fig. 1. In ll the cses, AB signl ws clerly distinguished with gret resolution, nd when ssying plsm no interfering pek t the retention time for AB ws present in blnk plsm or plsm smples spiked with AB. Quntifiction bsed on pek-re of AB ws found to yield more consistent nd reproducible results thn pek-height clcultions. Liner regression nlysis of the dependence of pek re response (y) on the theoreticl concentrtion (x) gve the eqution y = 27, ,726x. The correltion coefficient ws r 2 = This coefficient confirmed the linerity of the method over the concentrtion rnge ssyed ( μg/ml). Tble 1 shows the ANOVA nlysis of the linerity study. The R-squred sttistic indictes tht the model s fitted explins 99.7% of the vribility in AUC. Since the p-vlue in the ANOVA tble ws less thn 0.01, there ws sttisticlly significnt reltionship Figure 1. Representtive chromtogrms of AB in MeOH:H 2 O (A), blnk plsm smple (B) nd AB in plsm (C).

4 HPLC ssy for determintion of mphotericin B in biologicl smples ORIGINAL RESEARCH 405 Tble 1. Anlysis of vrince with the lck-of-fit test Source Sum of squres d.f. Men squre F-rtio p-vlue Model , Residul Lck-of-Fit Pure Error Totl (Corr.) Degrees of freedom. Tble 2. Intr-dy vribilities of the HPLC ssy for AB Concentrtion Concentrtion (μg/ml) (μg/ml) found (men ± SD; n = 3) Found (%) RSD (%) ± ± ± ± ± ± Clculted from concentrtion nd expressed s recovery in percent, men ± SD, n = 3. Tble 3. Inter-dy vribilities of the HPLC ssy for AB Concentrtion Concentrtion (μg/ml) (μg/ml) Dy 1 Dy 2 Dy 3 Found (%) b RSD (%) ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± Men ± SD, n = 3. b Clculted from concentrtion nd expressed s recovery in percent, men ± SD, n = 9. between AUC nd concentrtion t the 99% confidence level. Furthermore, since the p-vlue for the lck-of-fit test in the ANOVA tble ws greter thn 0.10, the linel model ppered to be dequte for the observed dt. The detection nd quntifiction limits of the ssy for AB were found to be nd μg/ml, respectively. The intrdy vribilities of the ssy method re shown in Tble 2 nd the corresponding inter-dy vribilities in Tble 3. These dt indicted tht the ssy method ws reproducible within the sme dy nd within different dys; RSDs were less thn 5% for the ll smples over the concentrtion rnge ssyed. The ccurcy of the ssy method in determining AB concentrtions in MeOH:H 2 O nd spiked plsm specimens, respectively, is presented in Tbles 4 nd 5. The devition from theoreticl vlues ws below 5% t ll concentrtion levels studied for ech smple type. For tissue smples the vlues of ccurcy obtined were similr to the plsm specimens, nd the devition from theoreticl vlues ws lso below 5% t ll concentrtion levels for liver, spleen nd kidney smples. Tble 4. Accurcy of the method for nlysis of AB in spiked MeoH:H 2 O smples Concentrtion (μg/ml) Recovery (%) RSD (%) ± ± ± Men ± SD, n = ± % confidence limits > μ > Expressed s recovery in percent, men ± SD, n = 3. Tble 5. Accurcy of the method for nlysis of AB in spiked plsm smples Concentrtion (μg/ml) Recovery (%) RSD (%) ± ± ± Men ± SD, n = ± % confidence limits > μ > Expressed s recovery in percent, men ± SD, n = 3.

5 406 ORIGINAL RESEARCH R. Espd et l. Figure 2. AB concentrtion vlues vs time in plsm (A), liver (B), spleen (C) nd kidneys (D) fter the injection of AB-Mic t the dose of 2 mg/kg by the intrcrdic route in mice. Vlues t ech time re mens (n = 3). Appliction of the method to phrmcokinetic study The phrmcokinetics of AB in plsm, liver, spleen nd kidney in mice is shown in Fig. 2. AB concentrtions decresed fster in plsm thn in the other biologicl tissues. Figure 2 clerly shows how AB ws specilly ccumulted in spleen nd liver, wheres AB levels in kidney were reltively low. Similr AB tissue distribution hve been previously reported with AB lipid formultions (Andes et l., 2006; Olson et l., 2006). AB is useful drug for the tretment of cnine viscerl leishmnisis (Lmothe, 2001; Noli nd Auxili, 2005). This disese is cused by the prsite Leishmni infntum. This prsite is ccumulted in the reticuloendothelil system nd for this reson high AB concentrtions in liver, spleen nd bone mrrow re required to erdicte the prsite. AB is drug with nrrow therpeutic index nd so drug monitoring is recommended t lest during the first drug development stges with new formultion. For this reson preliminry limited phrmcokinetic study hs been performed in dog. Figure 3 shows the plsm AB concentrtions in dog fter n intrvenous dministrtion of 5 mg/kg of the AB-Mic formultion. Specilly relevnt is the possible AB ccumultion in bone mrrow where the prsite is usully present. In our experimentl conditions, the dog bone mrrow AB concentrtion t 24 h ws five times higher thn tht of plsm. CONCLUSIONS It cn be concluded from the present work tht the proposed HPLC method ws useful to detect with high linerity, sensitivity nd precision AB in queous smples, which ws useful for mesuring with substntil Figure 3. Plsm concentrtion time profile for AB fter the injection of AB-Mic t the dose of 5 mg/kg by intrvenous route in dog (n = 1). sensitivity nd relibility the drug in different conditions. According to this method, there ws no need to employ slts, nd therefore the risk of sturtion, brekdown or overpressure in the column ws reduced. Also, the method hs been used to determine plsm concentrtions nd it hs been successfully pplied to phrmcokinetic study of this drug in mice nd dog fter single dministrtion of AB-Mic, new formultion of AB. In this wy, the method described ws sensitive enough for the quntittive determintion of AB in different biologicl tissues. Moreover, the simplicity nd efficcy of the developed method s well s the reltively short retention times of AB llowed the nlysis of lrge number of smples in short time, providing fst nd inexpensive method for the therpeutic AB monitoring in clinicl lbortories. Acknowledgments We thnk Squibb Bristol Myers for hving supplied us with mphotericin B. This work ws prtilly supported

6 HPLC ssy for determintion of mphotericin B in biologicl smples ORIGINAL RESEARCH 407 by grnt from the Complutense University nd Mdrid Community Administrtion to the reserch group nd from Science nd Technology Interministeril Commission, Government of Spin (project AGL GAN). REFERENCES Alk A, Moy S nd Bekersky I. A high-performnce liquid chromtogrphic ssy for the determintion of mphotericin B serum concentrtions fter the dministrtion of AmBisome, liposoml mphotericin B formultion. Therpeutic Drug Monitoring 1996; 18: Andes D, Sfdr N, Mrchillo K nd Conklin R. Phrmcokineticphrmcodynmic comprison of mphotericin B (AMB) nd two lipid-ssocited AMB preprtions, liposoml AMB nd AMB lipid complex, in murine cndidisis models. Antimicrobil Agents nd Chemotherpy 2006; 50: Brrt G nd Legrnd P. Comprison of the efficcy nd phrmcology of formultions of mphotericin B used in tretment of leishmnisis. Current Opinion in Infectious Diseses 2005; 18: Brrett JP, Vrdulki KA, Conlon C, Cooke J, Dz-Rmirez P, Evns EG, Hwkey PM, Herbrecht R, Mrks DI, Morled JM, Prk GR, Senn SJ nd Viscoli C. A systemtic review of the ntifungl effectiveness nd tolerbility of mphotericin B formultions. Clinicl Therpeutics 2003; 25: Bekersky I, Fielding RM, Dressler DE, Lee JW, Buell DN nd Wlsh TJ. Plsm protein binding of mphotericin B nd phrmcokinetics of bound versus unbound mphotericin B fter dministrtion of intrvenous liposoml mphotericin B (AmBisome) nd mphotericin B deoxycholte. Antimicrobil Agents nd Chemotherpy 2002; 46: Echevrrí I, Brturen C, Renedo MJ nd Dios-Viéitez MC. Highperformnce liquid chromtogrphic determintion of mphotericin B in plsm nd tissue. Appliction to phrmcokinetic nd tissue distribution studies in rts. Journl of Chromtogrphy A 1998; 819: Egger P, Bellmnn R nd Wiedermnn CJ. Determintion of mphotericin B, liposoml mphotericin B, nd mphotericin B colloidl dispersion in plsm by high-performnce liquid chromtogrphy. Journl of Chromtogrphy B, Biomedicl Sciences nd Applictions 2001; 760: Eldem T nd Aricn-Cellt N. Determintion of mphotericin B in humn plsm using solid-phse extrction nd high-performnce liquid chromtogrphy. Journl of Phrmceuticl nd Biomedicl Anlysis 2001; 25: Gllis HA, Drew RH nd Pickrd WW. Amphotericin B: 30 yers of clinicl experience. Reviews of Infectious Diseses 1990; 12: Hosotsubo H nd Hosotsubo K. Improved high-performnce liquid chromtogrphic determintion of mphotericin B in humn serum nd plsm. Journl of Phrmceuticl nd Biomedicl Anlysis 1989; 7: ICH Hrmonised Triprtite Guideline. Vlidtion of Anlyticl Procedures: Methodology, ICH Topic Q2B. The Europen Agency for the Evlution of Medicinl Products: London, Lmothe J. Activity of mphotericin B in lipid emulsion in the initil tretment of cnine leishmnisis. The Journl of Smll Animl Prctice 2001; 42: Lue LP, Hdmn ST nd Vncur A. Liquid chromtogrphic determintion of mphotericin B in different phrmceuticls. Journl of AOAC Interntionl 2002; 85: Murry HW. Tretment of viscerl leishmnisis in The Americn Journl of Tropicl Medicine nd Hygiene 2004; 71: Noli C nd Auxili ST. Tretment of cnine Old World viscerl leishmnisis: systemtic review. Veterinry Dermtology 2005; 16: Olliro PL, Guerin PJ, Gerstl S, Hskjold AA, Rottingen JA nd Sundr S. Tretment options for viscerl leishmnisis: systemtic review of clinicl studies done in Indi, The Lncet Infectious Diseses 2005; 5: Olson JA, Adler-Moore JP, Schwrtz J, Jensen GM nd Proffitt RT. Comprtive efficcies, toxicities, nd tissue concentrtions of mphotericin B lipid formultions in murine pulmonry spergillosis model. Antimicrobil Agents nd Chemotherpy 2006; 50: Sánchez-Brunete JA, De MA, Rm S, Bolás F, Alund JM, Rposo R, Méndez MT, Torrdo-Sntigo S nd Torrdo JJ. Tretment of experimentl viscerl leishmnisis with mphotericin B in stble lbumin microspheres. Antimicrobil Agents nd Chemotherpy 2004; 48: The United Sttes Phrmcopei. Rockville, MD, Tiphine M, Letscher-Bru V nd Herbrecht R. Amphotericin B nd its new formultions: phrmcologic chrcteristics, clinicl efficcy, nd tolerbility. Trnsplnt Infectious Disese 1999; 4: