Base Degradation Products Research Articles

HPTLC method for determination of anti-hypertensive drug combination metoprolol succinate and dapagliflozin

Combination of Metoprolol Succinate and Dapagliflozin is recommended in the treatment of Hypertension. Accurate and precise thin layer chromatographic method has been developed for the determination of Metoprolol Succinate and Dapagliflozin in combination. Pre-coated silica gel G60—F254 aluminium sheet (10 × 10 cm),0.2 mm layer thickness used as stationary phase and n-Butanol: Ethyl acetate: Triethylamine (6:4:0.1 v/v/v) used as mobile phase. The method was found to be linear with a range of 200–1200 ng/band for DAP and 1000–6000 ng/band for MET with correlation coefficient (r2) 0.996 for both DAP and MET. The proposed method was validated as per ICH Q2 (R2) guideline with respect to linearity, accuracy and precision. Stress degradation was carried out to find out the intrinsic stability of the molecules. Both the drugs were highly susceptible to acid and base hydrolysis and degradation products were well separated with drug peak. The method was successfully used for determination of metoprolol succinate and dapagliflozin in combination.

A Systematic Degradation Kinetics Study of Dalbavancin Hydrochloride Injection Solutions

The degradation kinetics of the glycopeptide antibiotic dalbavancin in solution are systematically evaluated over the pH range 1–12 at 70°C. The decomposition rate of dalbavancin was measured as a function of pH, buffer composition, temperature, ionic strength, and drug concentration. A pH-rate profile was constructed using pseudo first-order kinetics at 70°C after correcting for buffer effects; the observed pH-rate profile could be fitted with standard pseudo first order rate laws. The degradation reactions of dalbavancin were found to be strongly dependent on pH and were catalyzed by protons or hydroxyl groups at extreme pH values. Dalbavancin shows maximum stability in the pH region 4–5. Based on the Arrhenius equation, dalbavancin solution at pH 4.5 is predicted to have a maximum stability of thirteen years under refrigerated conditions, eight months at room temperature and one month at 40°C. Mannosyl Aglycone (MAG), the major thermal and acid degradation product, and DB-R6, an additional acid degradation product, were formed in dalbavancin solutions at 70°C due to hydrolytic cleavage at the anomeric carbons of the sugars. Through deamination and hydrolytic cleavage of dalbavancin, a small amount of DB-Iso-DP2 (RRT-1.22) degradation product was also formed under thermal stress at 70°C. A greater amount of the base degradation product DB-R2 forms under basic conditions at 70°C due to epimerization of the alpha carbon of phenylglycine residue 3.

A Validated Stability-Indicating HPLC-PDA Method for Tolnaftate: Identification, Characterization and In Silico Toxicity Predictions of Major Degradation Products.

Simple and rapid stability indicating High Performance Liquid Chromatography-Photo Diode Array (HPLC-PDA) method was developed and validated for the estimation of tolnaftate in the presence of its forced degradation products. The method employed SunQSil C18 column (250mm × 4.6mm, 5μm) as stationary phase and acetonitrile:water (85:15, v/v) as mobile phase. Retention time of tolnaftate was 6.9min. Acid and alkali hydrolysis, oxidation, photo degradation and thermal degradation studies were carried out to evaluate the degradation behavior of tolnaftate. The developed and optimized method was validated as per International Conferences on Harmonization (ICH) guidelines. Limit of detection and limit of quantitation were found to be 0.092 and 0.276μg/mL, respectively. Linearity was observed in a concentration range of 0.276-6μg/mL with R2= 0.9936. %Recovery was found to be between 98.28% and 100.71%. The developed and validated Reversed Phase-High Performance Liquid Chromatography (RP-HPLC) method was successfully applied for quantification of tolnaftate in in-house topical solution. Major base and oxidative degradation products were identified and characterized by liquid chromatography-electrospray ionization mass spectrometry. The probable mechanisms for the formation of degradation products were predicted based on the fragmentation pattern of degradation products. The in silico dermal penetration predictions and carcinogenicity of degradation products were evaluated by using QikProp and CarcinoPred-EL functionality.

A systematic approach for stability-indicating HPLC method optimization for Nilotinib bulk through design of experiments: Application towards characterization of base degradation products by mass spectrometry

A novel and reliable stability-indicating high-performance liquid chromatography method was developed using design of experiments. Under forced degradation conditions (hydrolysis, oxidative, photolytic and thermal) Nilotinib produced five major degradation products utilizing sodium hydroxide in base hydrolysis. The degradation products were separated by Hypersil ODS column (150×4.6mm i.d., 5μ) utilizing methanol and 10mM ammonium acetate (pH 3.0, adjusted with acetic acid) as mobile phase in gradient elusion mode at a flow rate of 1.2mL/min column temperature set at 35°C and UV detection at 263nm. Tandem mass spectrometry method was used to characterize the base degradation products by accurate mass measurements. The developed method was found to be linear, accurate, precise and selective for the separation of Nilotinib from its degradation products as per the International Conference on Harmonisation guidelines. The structures of the degradation products have been elucidated, of which three degradation products were reported for the first time.

FORCED DEGRADATION STUDIES OF NILOTINIB HYDROCHLORIDE: ISOLATION, IDENTIFICATION & CHARACTERIZATION OF IMPURITIES

Nilotinib hydrochloride is a tyrosine kinase inhibitor approved for the treatment of chronic myelogenous leukemia was subjected to forced degradation studies and the samples were analyzed by utilizing the LCMS compatible HPLC methods. Nilotinib Hydrochloride was subjected to thermal, hydrolytic, oxidative, acidic, basic and photolytic degradation conditions as per the regulatory guidelines. The drug was degraded in oxidative, basic and acidic environments and stable in photolytic and thermal conditions. The main degradation impurity components produced through the forced degradation study were isolated for the identification and quantification in presence of these impurities in the stability studies of drug substances as well as drug products. The identified degradation components were separated by mass assisted auto-purification technique and subjected for the characterization by NMR (13C-NMR, 1H-NMR, HMBC and HSQC), HRMS and FT-IR experimentations. Degradation products obtained from oxidative, basic and acidic environments were isolated and identified by the advanced techniques as acid degradation product (DP-1) with molecular mass of 306.11 g/mol, empirical formula C17H14N4O2 with name as 4-methyl-3- (4 -(pyridine -3-yl) pyrimidin -2 -ylamino) benzoic acid. Base degradation product (DP-2) has molecular weight of 241.08 g/mol, molecular formula C11H10F3N3 with name as 3-(4-methyl-1H-imidazol-1-yl)-5-(trifluoromethyl)aniline.Oxidative degradation product (DP-3) has molecular weight of 545.18 g/mol, molecular formula C28H22F3N7O2 with name as 3-(2-(2-methyl-5-(3-(4-methyl-1H-imidazol-1-yl)-5-(trifluoromethyl)phenylcarbamoyl) phenylamino)pyrimidin-4-yl)pyridine1-oxide.

Identification, isolation, structural characterisation, synthesis and in silico toxicity prediction of the alkaline hydrolytic degradation product of brivaracetam by using LC-PDA, preparative HPLC, LC/HESI/LTQ, FTIR, and 1H NMR.

Brivaracetam is a racetam derivative of levetiracetam with very limited data available on its degradation behaviour. An official HPLC method for brivaracetam has not been published yet to resolve the degradation products generated during stability studies. Therefore, an isocratic reverse phase HPLC-UV method was developed for the determination of brivaracetam in the presence of its related impurities and degradation products. Efficient chromatographic separation was achieved on an Inertsil ODS 3 V, 150 mm × 4.6 mm, 5 μ column with the mobile phase containing a mixture of 0.1% v/v trifluoroacetic acid solution and acetonitrile (60 : 40 v/v) at a flow rate of 1.0 ml min-1 with the eluent monitored at 210 nm. The proposed method was validated as per the ICH Q2 (R1) guidelines. The method was validated for specificity, linearity, precision, accuracy and robustness. For the assay, the calibration plot was linear over the concentration range of 141 μg ml-1 to 262 μg ml-1 of brivaracetam with a correlation coefficient (r2) of 0.99981. For the study of related substances, the calibration plot was linear over the concentration range of 0.0147 μg ml-1 to 2.93 μg ml-1 of brivaracetam with a correlation coefficient (r2) of 0.99994 and 0.0148 μg ml-1 to 2.96 μg ml-1 of the base degradation product of brivaracetam with a correlation coefficient (r2) of 0.99994. The proposed method was used to investigate the degradation kinetics of brivaracetam under different stress conditions. The drug was found to be less stable under basic degradation conditions. The method shows consistent recoveries for brivaracetam (100.22% at the 70% level, 100.02% at the 100% level and 99.14% at the 130% level of the test concentration i.e. 200 μg ml-1 of brivaracetam). The method was found to be accurate, precise, linear, specific, sensitive, rugged, robust, and useful for characterizing the stability of the drug molecule. The marketed formulation (brand name: Briviact) was analysed by using the proposed method; we have carried out identification, isolation, structural characterisation and in silico toxicity prediction of the alkaline hydrolytic degradation product of brivaracetam by using LC-PDA, preparative HPLC, LC/HESI/LTQ, FTIR and 1H NMR. The predicted alkaline degradation product was found to be 2-(4-methyl-2-oxo-1-pyrrolidinyl) butyric acid (i.e. a brivaracetam acid impurity generated after alkaline hydrolysis of brivaracetam). In silico toxicity prediction was carried out by using the eMolTox webserver. The synthesis of isolated impurities of brivaracetam has also been carried out successfully.

Isolation and characterization of the acid and base degradation products of andrographolide.

Andrographolide was subjected to degradation under acidic and basic conditions. Three degradation products including two novel compounds, 8,9-didehydroandrographolide (AG-A) and 15-seco-andrographolide (AG-B2), and a known product, 14-deoxy-11,12-didehydroandrographolide (AG-B1), were isolated by chromatography and identified on the basis of their NMR and MS data. The degradation product, AG-A, may result from the isomerization of andrographolide under acidic conditions whereas the base degradation products, AG-B1 and AG-B2, were formed most likely due to the dehydration of allyl alcohol and the hydrolysis of andrographolide at the lactone ring, respectively.

Utility of Synchronous Spectrofluorimetric Method for Rapid Selective Determination of Bimatoprost: Stress Stability Study and Green Analytical Application

Stability indicating Synchronous spectrofluorimetric (SF) method has been proposed and validated for the determination of bimatoprost in presence of its acid, base, and oxidative degradation products by measuring SF at 272 nm using delta lamba (∆λ)=30 nm in water. Bimatoprost was subjected to stress conditions of 2 M HCL, 2 M NaoH and 30% H2O2 . The identification of degradation products were done by LC-MS. The pathway of degradation was postulated. The effect of different experimental parameters on the fluorescence of the drug was studied and optimized. The range of linearity was over 25-250 ng/mL, the detection limit of 0.005 ng/ mL, and quantitation limit of 0.018 ng/ mL for bimatoprost. The developed method was validated according to ICH guidelines. The accuracy was checked by applying the proposed method for the determination of the drug and it’s degradant. The mean recoveries percentages were found to be 99.39 ± 1.08. RSD values for precision (repeatability and intermediate) testing was 0.569 and 1.28 respectively. The developed method was applied effectively for analysis of the drug in its ophthalmic formulation. The developed method was statistically compared with the reported method revealing high accuracy with good precision. The suggested method was found to be a green analytical chemistry method; the solvent used is water and hence that method can be suitable for routine analysis of the studied drug without effecting the environment harmfully

Development and Validation of Stability Indicating RP HPLC method for the estimation of armodafinil and Characterization of its base Degradation Product by LC-MS/MS

The present work focuses on the development and validation of a rapid, selective and reliable stability indicating reverse phase High Performance Liquid Chromatographic method for the quantitative analysis of Armodafinil (ARM). Armodafinil is a eugeroics drug used for treatment of narcolepsy and shift work sleep disorder and also as an adjunctive treatment for obstructive sleep apnea. The separation was carried out on a Hibar Purospher C18 (250 mm × 4.6 mm; 5μ) column by using 0.01 M ammonium formate (pH 4.5, Adjusted with acetic acid) and methanol as mobile phase in the ratio of 45:55 % v/v. The flow rate was maintained at 1 mL/min and the eluents were monitored at 220 nm. Stress studies were carried out with 1 mg/mL of the drug solution, starting with mild conditions and followed by intrinsic conditions to achieve sufficient degradation. Armodafinil underwent extensive degradation under basic hydrolysis condition. The unknown degradation product formed (DP I; 6.59±0.2 min) under the basic degradation condition was separated on a semi preparative HPLC, characterized by UPLC-Q-TOF and its fragmentation pathway was proposed. The proposed structure of the degradation product was confirmed by HRMS analysis. The developed stability indicating LC method was validated with respect to accuracy, precision, specificity/selectivity and linearity. The degradation product was characterized and reported.

Forced degradation of nepafenac: Development and validation of stability indicating UHPLC method

This paper presents stability study of the nonsteroidal anti-inflammatory drug (NSAID) nepafenac. In order to investigate stability of nepafenac, it was subjected to forced degradation under different stress conditions: acid and base hydrolysis, oxidation, humidity, heat and light. A novel stability indicating reverse phase ultra high performance liquid chromatographic (UHPLC) method coupled to ultraviolet detector has been developed to separate nepafenac and all related compounds (2-aminobenzophenone, Cl-thionepafenac, thionepafenac, Cl-nepafenac, hydroxy-nepafenac, and cyclic-nepafenac). Efficient chromatographic separation was achieved on a Waters Acquity BEH C18 stationary phase with a gradient elution. Quantification was carried out at 235nm at a flow rate of 0.6mL/min−1. The resolution between nepafenac and six potential impurities is found to be greater than 2.0. The developed method was validated with respect to specificity, LOD, LOQ, linearity, precision, accuracy and robustness. The r2 values for nepafenac and six potential impurities were all greater than 0.999. The developed method is capable to detect impurities of nepafenac at a level of 0.005% with respect to test concentration of 1.0mg/mL. Significant degradation is observed in acid, base and oxidative degradation conditions and degradation products (DPs) were identified using mass spectrometry analysis; two of them were found to be a known process related impurities (hydroxy- and cyclic-nepafenac) whereas four degradation products were identified as new degradation impurities. The forced degradation samples were assayed against a qualified reference standard and the mass balance was found to be close to 99.5%.

Isolation and characterization of acid and base degradation products in Atenolol and Hydrochlorothiazide and a validated selective stability-indicating HPLCUV method for their quantification

Atenolol (( RS )-2-{4-[2-Hydroxy-3-(propan-2-ylamino)propoxy]phenyl}acetamide) and Hydrochlorothiazide (6-chloro-1,1-dioxo-3,4-dihydro-2 H -1,2,4-benzothiadiazine-7-sulfonamide) are beta 1 (? 1 ) receptor blocker and diuretic drug respectively; however the combination dosage regime are used for cardiovascular therapy. Thus a forced degradation study was carried out upon this combination drug regime under acidic and basic environment in order to deconvolute the possible degradation product under specified stressed conditions. Under acidic conditions atenolol and hydrochlorothiazide were cleaved into 2-(4-(3-amino-2- oxopropoxy) phenyl) acetamide and 6-sulphamido benzothiazide. However, under basic conditions, the drugs were spliced into 2-(4-(2-hydroxypropoxy) phenyl) acetamide and 2-chloro 4-amino 1, 6-dihydro benzene sulphonamide respectively. The degradant peaks were elucidated by HPLC using C18 column with methanol: phosphate buffer (70:30 v/v) with a flow rate of 0.5ml/min (UV detection at 226nm).. For quantitative method validation, linearity was observed over product concentration range 2g/ml - 100 g/ml (r 2 0.9992) with regression equation y=43432x. The products were first identified by LC-MS and further confirmed by FT-IR and 1 H 1 NMR. A specific and sensitive stability-indicating assay method for the simultaneous determination of the drugs, its process related impurities and degradation products was developed.

Hydrolytic Degradation Study of Lansoprazole, Identification, Isolation and Characterisation of Base Degradation Product

Lansoprazole degradation is accelerated in both acidic and basic medium in water. The present investigation deals with the hydrolytic degradation of Lansoprazole. Acidic medium degradation show all known impurities and degradation products whereas basic degradation studies show new impurity which has higher molecular weight than Lansoprazole. New impurity was identified, isolated using mass based auto purification system and characterised by 1H NMR, 13C NMR, HMBC, HSQC, NOE, COSY and HRMS experiments. Isolated impurity was showing molecular weight of 467.10, molecular formula of C23H16F3N5OS and its name is 7-(3-Methyl-4-(2,2,2-trifluoroethoxy) pyridin-2-yl)-7H-benzo[4,5]imidazo[2,1-b]benzo[4,5]imidazo[2,1-d][1,3,5]thiadiazine.

Development and validation of stability-indicating HPLC method for solifenacin succinate: Isolation and identification of major base degradation product

Summary Stability-indicating HPLC method was developed for determination of solifenacin succinate (SLN) as bulk drug and from pharmaceutical formulation. The HPLC separation of SLN from its degradation products was achieved using Oyster BDS C8 (250 mm × 4.6 mm i.d., 5 μm particle size) column with a flow rate 0.7 mL min−1 and using a UV detector to monitor the eluate at 210 nm. The mobile phase was composed of 10 mM ammonium formate buffer (adjusted pH 3 with formic acid)-acetonitrile-methanol (52.5:37.5:10, v/v/v). The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.9999 in the working concentration range of 2–100 μg mL−1. The limit of detection (LOD) and limit of quantification (LOQ) were 0.07 and 0.21 μg mL−1, respectively. API and formulation of SLN were subjected to acid and alkali hydrolysis, oxidation, thermal and photodegradation. Standard drug peak was well resolved from the peaks of degradation products with significantly different retention time values. Also, isolation and identification of major base degradation product were carried out. The method is simple, accurate, specific, repeatable, stability-indicating, reduces the duration of the analysis and is suitable for routine determination of SLN in pharmaceutical formulation.

Characterization of related impurities in cefotetan bulk material by high-performance liquid chromatography-electrospray tandem mass spectrometry

LC/MS methods were developed for rapid identification of 4 impurities in cefotetan. Based on the degradation mechanism of Cephalosporins , stress tests were designed and performed, and it was found that two main impurites were base degradation products. Cefotetan disodium bulk material was separated on a C18 column, with 1% ice acetate solution-acetonitrile-methanol (80:10:10) as mobile phase. Under the negative ion mode, four impurities were separated from cefotetan components and identified on the basis of MS/MS spectra and the proposed general fragmentation pathway of cefotetan, as well as the UV spectra. Four impurites were characterized as 5-mercapto-1-methyl-tetrazole, cefotetan lactone, decarboxyl-cefotetan, and isomer cefotetan. Therefore, the method is rapid, sensitive and specific, and it is suitable for the identification of the impurities of cephalosporin.

Acid and base degraded products of ketorolac

The stability of ketorolac tromethamine was investigated in acid (0.5 M HCl) and alkaline conditions (0.5 M NaOH), using the same procedure reported by Devarajan et al. [2]. The acid and base degradation products were identified by liquid chromatography–mass spectrometry (LC–MS).

Isolation, Synthesis, and Characterization of Impurities and Degradants from the Clofarabine Process

The identification of clofarabine process impurities and their subsequent isolation, synthesis, and characterization is described. Two isomeric process impurities resulting from N6-attachment of a fluoroarabinose to clofarabine were found. Clofarabine’s base degradation products, which were different from the process impurities, were also synthesized and characterized. These compounds resulted from modifications to the sugar moiety, the purine ring, or both. A mechanistic rationale for the formation of the various process impurities and degradation products is provided.

Analysis of Fluoroquinolone-mediated Photosensitization of 2′-Deoxyguanosine, Calf Thymus and Cellular DNA: Determination of Type-I, Type-II and Triplet-Triplet Energy Transfer Mechanism Contribution¶

Fluoroquinolone (FQ) antibacterials are known to exhibit photosensitization properties leading to the formation of oxidative damage to DNA. In addition, photoexcited lomefloxacin (Lome) was recently shown to induce the formation of cyclobutane pyrimidine dimers via triplet–triplet energy transfer. The present study is aimed at gaining further insights into the photosensitization mechanisms of several FQ including enoxacin (Enox), Lome, norfloxacin (Norflo) and ofloxacin (Oflo). This was achieved by monitoring the formation of DNA base degradation products upon UVA-mediated photosensitization of 2′-deoxyguanosine, isolated and cellular DNA. Oflo and Norflo act mainly via a Type-II mechanism whereas Lome and, to a lesser extent, Enox behave more like Type-I photosensitizers. However, the extent of oxidative damage was found to be relatively low. In contrast, it was found that cyclobutane thymine dimers represent the major class of damage induced by Enox, Lome and Norflo within isolated and cellular DNA upon UVA irradiation. This striking observation confirms that FQ are able to promote efficient triplet energy transfer to DNA. The levels of photosensitized formation of strand breaks, alkali-labile sites and oxidative damage to cellular DNA, as measured by the comet assay, were confirmed to be rather low. Therefore, we propose that the phototoxic effects of FQ are mostly accounted for energy transfer mechanism rather than by Type-I or -II photosensitization processes.

A pH-Stability Study of Phoslactomycin B and Analysis of the Acid and Base Degradation Products

Phoslactomycin B (PLM-B), a potent and selective inhibitor of serine threonine phosphatase is of interest for its antitumor, antifungal and antiviral activity. Described herein is an evaluation of the solution stability of phoslactomycin B at various pH and temperature conditions. Phoslactomycin B was produced from a NPI mutant strain of Streptomyces sp. HK-803 and purified by semi-preparative HPLC. A study of PLM-B degradation was carried out in the pH range of 2 approximately 10 at 30 degrees C and 50 degrees C using an HPLC assay. The PLM-B decomposition was observed to exhibit a U-shaped pH profile and demonstrated both acid and base-catalyzed decomposition. The decomposition could be described by the equation kOBS=kH x 10(-PH) + kOH x 10(pH-14) (kH=45 +/- 7 M(-1) h (-1); kOH= 448+/-73 M(-1h)(-1). PLM-B was found to be most stable at pH 6.63. The major acid and base products were separated and purified. Mass spectroscopic and NMR analysis revealed hydrolysis of the alpha, beta-unsaturated lactone provided the major degradation product under base conditions. Two other products in which hydration of the alpha, beta-unsaturated double bond preceded hydrolysis or methanolysis of the lactone were obtained. Under acidic condition MS and NMR analysis revealed that a dehydration step provided a C9-C11 phosphorinane derivative of PLM-B as one of the major products. The remaining acid degradation products were shown to be mixture of various dehydration products containing an additional double bond in central core of the PLM-B carbon skeleton. The major acid and base degradation products had dramatically reduced antifungal activity despite retaining the same structural core.

Analysis of fluoroquinolone-mediated photosensitization of 2'-deoxyguanosine, calf thymus and cellular DNA: determination of type-I, type-II and triplet-triplet energy transfer mechanism contribution.

Fluoroquinolone (FQ) antibacterials are known to exhibit photosensitization properties leading to the formation of oxidative damage to DNA. In addition, photoexcited lomefloxacin (Lome) was recently shown to induce the formation of cyclobutane pyrimidine dimers via triplet-triplet energy transfer. The present study is aimed at gaining further insights into the photosensitization mechanisms of several FQ including enoxacin (Enox), Lome, norfloxacin (Norflo) and ofloxacin (Oflo). This was achieved by monitoring the formation of DNA base degradation products upon UVA-mediated photosensitization of 2'-deoxyguanosine, isolated and cellular DNA. Oflo and Norflo act mainly via a Type-II mechanism whereas Lome and, to a lesser extent, Enox behave more like Type-I photosensitizers. However, the extent of oxidative damage was found to be relatively low. In contrast, it was found that cyclobutane thymine dimers represent the major class of damage induced by Enox, Lome and Norflo within isolated and cellular DNA upon UVA irradiation. This striking observation confirms that FQ are able to promote efficient triplet energy transfer to DNA. The levels of photosensitized formation of strand breaks, alkali-labile sites and oxidative damage to cellular DNA, as measured by the comet assay, were confirmed to be rather low. Therefore, we propose that the phototoxic effects of FQ are mostly accounted for energy transfer mechanism rather than by Type-I or -II photosensitization processes.

High-resolution LC/MS for analysis of minor components in complex mixtures: negative ion ESI for identification of impurities and degradation products of a novel oligosaccharide antibiotic.

High-resolution mass spectrometry has been routinely used for structural confirmation and identification; however, it has mostly been applied to relatively pure samples. Exact mass measurement of minor components such as impurities, degradation products or metabolites in complex mixtures has been difficult without prior separation and isolation. Here we report the utilization of on-line liquid chromatography in combination with high-resolution mass spectrometry for the identification of impurities and base degradation products of Sch 27899, a member of the everninomicin class of antibiotics. Nine Sch 27899-related impurities and degradation products were detected by negative ion electrospray ionization using a magnetic sector mass spectrometer. Exact mass measurements were obtained at a resolution of 5000 using polyethylene glycol (PEG) sulfates as internal standards. Corresponding elemental compositions were determined within a 2 ppm error tolerance and structures were proposed for all components.