Research ArticleARobust StaticHeadspaceGC-FIDMethod toDetect andQuantifyFormaldehyde Impurity in Pharmaceutical Excipients

Bashir Daoud Agha Dit Daoudy ,1 Mohammad Ammar Al-Khayat,1

Francois Karabet,2 and Mohammad Amer Al-Mardini1

1Department of Pharmaceutical Chemistry and Quality Control, Faculty of Pharmacy, Damascus University, Damascus, Syria2Department of Chemistry, Faculty of Science, Damascus University, Damascus, Syria

Correspondence should be addressed to Bashir Daoud Agha Dit Daoudy; bashir-daoudy@hotmail.com

Received 20 June 2017; Accepted 17 October 2017; Published 4 March 2018

Academic Editor: Krishna K. Verma

Copyright © 2018 Bashir Daoud Agha Dit Daoudy et al. )is is an open access article distributed under the Creative CommonsAttribution License, which permits unrestricted use, distribution, and reproduction in anymedium, provided the original work isproperly cited.

Formaldehyde is a highly reactive impurity that can be found in many pharmaceutical excipients. Trace levels of this impurity mayaffect drug product stability, safety, efficacy, and performance. A static headspace gas chromatographic method was developed andvalidated to determine formaldehyde in pharmaceutical excipients after an effective derivatization procedure using acidifiedethanol. Diethoxymethane, the derivative of formaldehyde, was then directly analyzed by GC-FID. Despite the simplicity of thedevelopedmethod, however, it is characterized by its specificity, accuracy, and precision.)e limits of detection and quantificationof formaldehyde in the samples were of 2.44 and 8.12 µg/g, respectively. )is method is characterized by using simple andeconomic GC-FID technique instead of MS detection, and it is successfully used to analyze formaldehyde in commonly usedpharmaceutical excipients.

1. Introduction

Although considered pharmacologically nonactive, pharma-ceutical excipients have critical effects on drug product safety,efficacy, and quality. During early stages of drug formulationdevelopment, excipients are evaluated for appropriateness bystudying their physical and chemical compatibility withdrug substances under stressed and accelerated conditions.Depending on the results of the compatibility studies, for-mulator can exclude incompatible excipients from later stagesof formulation development. Chemical incompatibility withdrug substances may result not only from direct reaction withexcipients but also from reaction with excipient impurities.)ese impurities include formaldehyde which could begenerated by autoxidation degradation of many pharma-ceutical excipients such as polyvinylpyrrolidone (PVP) andpolyethylene glycol (PEG) [1–4].

Pharmacopoeial monographs of pharmaceutical excip-ients rarely require testing for formaldehyde specifically[5, 6]. However, formaldehyde may negatively affect safety,

efficacy, chemical stability, and performance of dosageforms, even in trace amounts. It can form adducts with manypharmaceuticals containing nucleophilic functional groups,especially amine and hydroxyl groups [1, 2, 4], such as gelatin[7], varenicline [8], irbesartan [9], phenylephrine [10], andGDC-0973 [11]. Some of these adducts may have toxic effectssuch as the degradation product of melatonine with form-aldehyde [12].

Formaldehyde has a low molecular weight and a highchemical reactivity. Furthermore, it has little UV activity andlow detector sensitivity and specificity. Besides, it is soluble inbothwater and organic solvents. As a consequence, it is difficultto directly extract and determine formaldehyde in a specific,accurate, and sensitive way. )erefore, most of the analyticalmethods used for formaldehyde analysis employ chemicalderivatization to improve its stability and modify the physi-cochemical properties to enhance its detectability [11, 13–17].

Many analytical methods have been developed to deter-mine formaldehyde in pharmaceuticals and cosmetics. )esemethods are based on colorimetric, spectrophotometric,

HindawiJournal of Analytical Methods in ChemistryVolume 2018, Article ID 4526396, 8 pageshttps://doi.org/10.1155/2018/4526396

fluorescent, capillary electrophoresis, HPLC, GC, and GC-MStechniques [1, 17–20]. Lots of the reported methods have reliedon derivatizing formaldehyde using acetylacetone or chromo-tropic acid reagents prior to colorimetric and/or spectropho-tometric determination. However, the main disadvantages ofthese methods are the lack of appropriate specificity and/orsensitivity [1, 17, 20, 21]. 2,4-Dinitrophenylhydrazine, the mostpopular derivatization reagent, has been used before de-termination of formaldehyde by HPLC [11, 15, 22]. However,some of these methods have limited selectivity or have sufferedfrom difficulty handling and injecting excipient samples whichform viscous solution (such as PVP). In addition, other HPLCmethods require tedious and multisteps extraction proceduresand/or long analysis time [1, 16, 20, 23]. Gas chromatography isthe best choice for determination of volatile components, es-pecially when associated with the headspace sampling tech-nique.)is technique provides a simple way to directly inject theextracted volatiles into GC. In contrast with the direct injectionof the sample solution into GC inlet, the headspace injectionallows the volatiles to be analyzed without interference by thenonvolatile matrix. By using the headspace technique, analystscan also simply derivatize target components by utilizing theheadspace vial as a reaction vessel [24]. Few GC methods havebeen developed to determine formaldehyde in pharmaceuticalexcipients; however, the derivatization reaction, the extraction,and/or the sample preparation were generally complex and/orrequired long time [13, 16, 19, 20]. del Barrio et al. reporteda headspaceGC-MSmethod for determination of formaldehydein some excipients by converting it to diethoxymethaneusing acidified ethanol. In this method, the sample prep-aration was very simple and rapid, and the chemical de-rivatization can be carried out under mild conditions.However, the authors did not evaluate the capability ofusing FID for quantification [16]. Although FID is lesssensitive than MSD, it is the most widely used detector forroutine quantification in typical analytical laboratories. Inaddition, it is easier to operate and maintain [20, 25].

As most of the spectrophotometric methods have somedisadvantages, while other chromatographic methods arecomplex to be performed, the aim of this research is todevelop and validate a static headspace (SHS) GC-FIDmethod to determine formaldehyde, and then to use it asa screening method and a quality control tool to analyze thisimpurity in commonly used pharmaceutical excipients.

2. Materials and Methods

2.1. Standards, Reagents, and Chemicals. High-purity dieth-oxymethane (≥99.0%) was purchased from Aldrich (USA).Absolute ethanol (99.9%) and pure formic acid were purchasedfrom Panreac (Spain). Formaldehyde solution (37–41%) wasobtained from SCP (England). ACS grade p-toluenesulfonic acidmonohydrate (≥98.5%) was purchased from Sigma-Aldrich(Japan). All excipients used were of pharmaceutical grade.

2.2. Instrumentation. Experiments were conducted byAgilent Model 7890A gas chromatograph equipped withmass selective detector (MSD model 5975C) and associated

with GC sampler 80 enhanced with Agilent PAL headspaceoption. Agilent MSD Productivity ChemStation E.02.01.1177software was used to control, acquire, and process the chro-matographic data. A 30m× 0.25mm i.d. ZB-WAX columnwith 0.25µm film thickness (Phenomenex, USA) was utilizedfor gas chromatographic separation.

2.3. Headspace Sampling Parameters. )e headspace auto-sampler parameters were set as follows: incubation tem-perature: 70°C; incubation time: 25min for PVP samples and15min for PEG samples; syringe temperature: 75°C; agita-tion speed: 500 rpm; syringe injection volume: 800 µl; sy-ringe fill speed: 100 µl/s; syringe injection speed: 1000 µl/s; fillstrokes: 1; pull-up delay: 2 s; pre- and postinjection delay: 0.2and 0.4 s, respectively. Carryover in the headspace syringewas eliminated by an automatic syringe flush performedafter each injection.

2.4. GC Instrumental Conditions. )e injector was main-tained at 170°C with a split ratio of 1 : 25. )e column oventemperature program involved an initial temperature of35°C for 5min and increased at 40°C/min to 220°C and heldfor 1min.)e carrier gas was helium (99.999%) at a constantflow rate of 0.9mL/min. FID was set at 280°C for quanti-fication. MS detection was carried out at 230°C with full scan(31–250 amu) for identification.

2.5. Sample Preparation. Samples were prepared by directlyweighing 250mg of the tested excipient into a 20ml amberheadspace vial (Supelco). After that, 5mL of the solution of 1%(w/w) p-toluenesulfonic acid in ethanol was added to the contentof each sample vial which was then immediately sealed witha magnetic screw cap lined with a butyl/polytetrafluoroethyleneseptum (Supelco) and shaken for 2 minutes (until the contentbecomes completely dissolved). Finally, the prepared vials weresequenced and automatically moved to the incubator forcompleting the chemical derivatization of formaldehyde.

2.6. Standards Preparation. )e concentration of formal-dehyde solution was determined by applying the iodometricmethod described in British Pharmacopoeia 2013 [5]. )econcentration was 35.10% (w/w).

Standard solutions of formaldehyde were prepared in theacidified ethanol (1% p-toluenesulfonic acid). A stockstandard solution of formaldehyde at 1251.063 µg/ml wasprepared and used to prepare a series of standard solutions atlower concentrations by serial dilutions. )en, 5mL of eachstandard solution was transferred to a headspace vial andtreated as described above.

2.7. Method Validation. )e method was validated in termsof specify, linearity, accuracy, repeatability, intermediateprecision, limit of detection, and limit of quantificationaccording to British Pharmacopoeia 2013 [5].

2 Journal of Analytical Methods in Chemistry

2.8. Statistical Analysis. Results were statistically processedby t-test or one-way analysis of variance (ANOVA) in orderto evaluate signi�cant di�erences (p< 0.05). StatisticalPackage for the Social Sciences (SPSS, 20) software was usedfor this purpose.

3. Results and Discussion

3.1. Development and Optimization of SHS-GC-FID Method

3.1.1. Chromatographic Conditions

(1) Identi cation. ­e identi�cation of the derivative, theproduct of the chemical reaction of formaldehyde withethanol, was con�rmed by using the corresponding standard(diethoxymethane). As shown in Figure 1(B), the retentiontime of formaldehyde derivative peak (tR� 3.837min)matched with that belonging to the corresponding standardpeak eluted according to Figure 1(C). ­is indicates that thederivative was diethoxymethane.

To further con�rm the identity of formaldehyde de-rivative, EI mass spectrum of the corresponding peak(shown in Figure 2) in full scan was acquired and identi�edusing the NIST MS library as diethoxymethane.

3.1.2. Optimization of Sample Preparation and HeadspaceSampling

(1) Preliminary Investigation. At the beginning, the sample

preparation and the headspace sampling parameters de-scribed by del Barrio et al. [16] (the sample concentration:100mg/mL; the headspace parameter: incubation at 60°Cfor 15min) were applied for analyzing and evaluating therecovery of formaldehyde derivative from the spiked sam-ples of PEG 400 and PVP K-30. ­e results (n� 2) dem-onstrated that the mean recovery of formaldehydederivative from PEG 400 was within the acceptable range(80–120%); however, it was not so for PVP K-30 (56%).

In order to explore the factors that leaded to such lowrecovery of formaldehyde derivative from PVP K-30, thesample matrix e�ect and the previous incubation param-eters were checked. First, the experiments carried out onthe ethanolic solution of diethoxymethane standardshowed that the incubation time of 15min at the tem-perature of 60°C was su¢cient for diethoxymethane toreach the static headspace equilibrium. Second, the meanrecovery of diethoxymethane standard was 110% (n � 2)when preparing PVP K-30 samples by adding 5mL of theethanolic standard solution. ­us, there is no negativee�ect of PVP K-30 sample matrix on formaldehyde de-rivative extraction. ­ird, the incubation time required tocomplete the derivatization reaction of formaldehyde inPVP K-30 was evaluated at the temperature of 60°C. Asshown in Figure 3, the incubation for 15min was notsu¢cient for completing the derivatization reaction offormaldehyde. Rather, the incubation time should be ad-justed at 45min at least to ensure completion of the re-action. ­is di�erence in the incubation times required for

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Figure 1: Overlaid chromatograms show the conversion of formaldehyde in acidi�ed ethanol to the corresponding derivative. (A) Ethanol;(B) formaldehyde derivative; (C) diethoxymethane standard.

Journal of Analytical Methods in Chemistry 3

PVP K-30 sample may be due to existence of a relationshipbetween the physical nature of the sample and the kinetic ofthe derivatization reaction of formaldehyde.

(2) E�ect of Sample Dilution on Incubation Time. ­e rel-atively high viscosity of ethanolic solution of PVP K-30,when prepared at concentration of 100mg/mL, may be thereason behind the long time required to reach equilibrium forformaldehyde derivative (Figure 3). Although sample di-lution can decrease sensitivity of the analytical method,however, it can reduce viscosity of the ethanolic solution ofPVP K-30, which can in turn decrease the required time for

both completing the derivatization reaction and reachingequilibrium for formaldehyde derivative between thesample and the headspace gas phases [24]. ­erefore, thesample concentration of 50mg/mL was used to evaluatethe required incubation time for the spiked PVP K-30samples while �xing the incubation temperature at 60°C.Figure 3 shows the diagram which correlates between thepeak area of the derivative and the increased incubationtime.­e results demonstrated that there was no signi�cantincrease in the peak area of formaldehyde derivative after30min incubation.

As a consequence, sample dilution from 100mg/mL to50mg/mL gave the advantage of lowering the incubationtime to 30min (instead of 45min at least). ­erefore, thesample concentration of 50mg/mL was selected to completethe other experiments.

(3) E�ect of Increasing the Incubation Temperature. In-creasing the incubation temperature generally leads to anincrease in the rate of the derivatization reaction and theheadspace sensitivity. On the other hand, it results in de-creasing the required time to reach the static headspaceequilibrium [24]. ­erefore, the incubation temperature wasraised to 70°C (higher temperatures were not experimentedto avoid any potential degradation of the samples). ­eresults (shown in Table 1) indicate that there was no sig-ni�cant increase (t-test, p> 0.05) in the detector responsewhen the reaction mixture was incubated at 70°C (instead of60°C) for 30min. Hence, there was no increase in thesensitivity. In contrast, the incubation time required tocomplete the derivatization reaction of formaldehyde in

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Figure 3: E�ect of incubation time at 60°C on formaldehydederivative peak area in PVP K-30 when the sample concentration is50mg/mL (blue box) and 100mg/mL (red box).

4 Journal of Analytical Methods in Chemistry

excipient samples decreased. Figure 4 shows the plateau ofthe peak area of formaldehyde derivative with increase inincubation time at 70°C for both PEG 400 and PVP K-30.­e data show no signi�cant increase in the peak area offormaldehyde derivative after 15min for PEG 400 and25min for PVP K-30.

As a consequence, the increasing of incubation tem-perature from 60°C to 70°C leaded to a decrease in theincubation time from more than 15min to 15min for PEG400 and from 30min to 25min for PVP K-30. ­erefore, theincubation temperature of 70°C was selected.

(4) Headspace Sampling Parameters. Headspace samplingparameters other than incubation time (injection speed andinjection volume) were optimized and set in a way that canachieve a balance between the sensitivity and the peak shapeparameters. ­e �nal headspace sampling parameters aregiven in Section 2.3.

3.1.3. E�ect of Water Presence on FormaldehydeDetermination. Diethoxymethane formation reaction issusceptible to water presence which can reverse the reaction[16, 26]. ­erefore, the tolerance of the derivatization re-action of formaldehyde to water was evaluated by adding itto several vials containing 5mL of the reaction mixture(formaldehyde in acidi�ed ethanol at a concentration of1.5 µg/mL) at the following amounts: 0, 12.5, 25, and 50mg(0, 5, 10, and 20% w/w relative to the sample weight 250mg).After analysis and statistical processing, the results (shownin Table 2) manifested that there was no signi�cant di�er-ence (ANOVA test, p> 0.05) between the control (0% water)and the other samples.

As a consequence, excipient samples containingwater≤ 20% (w/w) can be analyzed without any signi�cante�ects on formaldehyde determination. Higher amounts ofwater were not experimented because the acceptable limitsof water content stated in the monographs of PEG and PVPare 1–2% and 5%, respectively [5, 6].

3.2. SHS-GC-FID Method Validation

3.2.1. Speci city. ­e speci�city of the method was de-termined by comparing the chromatograms (SupplementaryMaterial Figure S1) of the blank (acidi�ed ethanol), thestressed excipients dissolved in ethanol and the standardsolution of formaldehyde in the blank. ­e chromatogramsshowed that there were no interferences at the retention timeof formaldehyde derivative peak. In addition, all volatilecomponent peaks, which appeared after analyzing spikedexcipient samples, dissolved in the blank (SupplementaryMaterials Figures S2 and S3) were completely separated fromthe analyte peak (the resolution between the analyte peakand any other one was more than 2).

3.2.2. Linearity. ­e linearity of the method was evaluatedfrom injection of nine concentrations of formaldehyde at therange of 0.25–50 µg/ml. ­e analyte showed excellent linearbehavior over the speci�ed range with coe¢cient of cor-relation (R2) value of 1.

3.2.3. Accuracy. ­e accuracy of the optimized method wasdetermined by spiking the excipient samples with knownamounts of formaldehyde at four concentration levels(n� 3). ­e results (shown in Table 1) were expressed asmean recoveries. ­e recovery at all concentration levels waswithin the acceptable range (80–120%). ­is indicates thatthe method is accurate.

3.2.4. Precision. ­e precision of the method was evaluatedin terms of the repeatability (expressed as intraday pre-cision) and the intermediate precision (expressed asinterday precision). ­e repeatability of the method wasestablished from triplicate (n � 3) injections of each spikedexcipient sample at each concentration level. Intermediateprecision (interday precision) was carried out by analyzingthe spiked excipient samples, prepared in the same wayand at the same concentration levels, on two di�erent daysby two di�erent analysts. ­e results of the method pre-cision (shown in Table 3) were expressed as a relativestandard deviation (RSD%). All RSDs were less than 4%.­is indicates that the method is precise.

3.2.5. Limits of Detection and Quanti cation. ­e limits ofdetection and quanti�cation (LOD and LOQ, resp.) wereevaluated based on signal-to-noise ratios of 3 and 10, re-spectively, and the respective values were found to be 121.80and 406.00 µg/L. Because the sample concentration was50mg/mL, LOD in excipient samples was 2.44 µg/g, whileLOQ was 8.12 µg/g.

Table 1: E�ect of incubation temperature on response (n� 2).

Incubation temperature (°C) Response (mean± SD)60 230299± 487270 233366± 4779aaNo signi�cant di�erence when compared with incubation at 60°C.

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Figure 4: E�ect of incubation time at 70°C on formaldehydederivative peak area. Formaldehyde in PVP K-30 (red box) andformaldehyde in PEG 400 (blue box).

Journal of Analytical Methods in Chemistry 5

3.2.6. Robustness. Changing the flow rate within±0.1mL/min had no effect on the area of formaldehydederivative peak, and all RSDs were less than 5%. )is in-dicates the robustness of the method.

3.3. Performance of the Proposed Method. Little analyticalmethods have been developed to determine formaldehyde inpharmaceutical excipients [13]. Table 4 shows a comparisonbetween these methods and the proposed one.

Compared to other methods, the time required tocomplete formaldehyde determination using the developedmethod was generally faster. Recovery obtained with thepresented procedure was comparable with those reported byothers. Precision of the method was also close to thosementioned by others; however, it was better than that forSPME-based method. Although the proposed method hadlower sensitivity than most of the other methods, however, itgives the opportunity to detect and determine formaldehydeimpurity in pharmaceutical excipients below the limit statedin British pharmacopoeia (15 ppm for free formaldehyde inPEG) [5].

3.4. Analysis of Commercial Pharmaceutical ExcipientSamples. PVP and PEG are widely used in many

pharmaceutical applications and dosage forms. )ey areutilized in drug products over a wide range of concentra-tions.)ese concentrations can reach up to 67% for PEG 400and 25% for various grades of PVP [3, 27].

)e optimized SHS-GC-FID method was applied toanalyze the presence of formaldehyde in several commercialPEG and PVP samples. )e results of the analysis aresummarized in Table 5.

Formaldehyde content in the excipient samples wasextensively varied from 8.04 to 190.58 µg/g. )ese variationsdepended on the nature, the storage conditions, and thesource of the excipient samples.

Table 3: Accuracy, intraday, and interday precision of the developed method.

Formaldehydespiked (µg/g)

PVP K-30 PEG 400Mean recovery

% (n� 3)Intraday precision(RSD%) (n� 3)

Interday precision(RSD%) (n� 6)

Mean recovery% (n� 3)

Intraday precision(RSD%) (n� 3)

Interday precision(RSD%) (n� 6)

10.0 104.27 2.65 1.92 87.76 0.75 3.1850.04 98.14 1.48 1.56 89.79 1.59 3.24500.4 98.99 2.96 3.61 97.70 2.04 2.671000.9 97.89 1.52 1.56 101.12 2.07 2.05

Table 4: Comparison between the methods used to determine formaldehyde in excipients or drug substances.

Analyticaltechnique

Derivatization and/orextraction times (min)

Run time(min)

Approx. recovery(%)

Approx. precisiona

(%)Approx. LODb

(ppm) Ref.

GC-FID 5 >7 No data No data 7 [21]GC-MS 240 15 86–99 3.7 0.02 [19]SHS-GC-FID 30 5 85–97 ≤3 0.05 [20]SHS-GC-MS 20 28 No data 3.1 0.05 [20]SPME-HS-GC-MSc 60 22.5 106.5–113.5 3.13–13.19 No data [18]HPLC-UV No data ≥35 84–97 0.5–1.2 0.5 [22]HPLC-UV 60 30 No data No data 0.03 [15]HPLC-UV No data No data 94.9–102.9 No data 10 [23]Proposed method 15 or 25 11 87.8–104.3 0.75–3.6 2.44 —aIncluding inter- and intraday precision; bLOD in sample; cSPME: solid-phase microextraction.

Table 2: Effect of water content on formaldehyde determination (n� 2).

Percentage of water relative to sample weight (%) 0 5 10 20Formaldehyde concentration (µg/mL) (mean± SD) 1.45± 0.025 1.48± 0.009a 1.48± 0.025a 1.48± 0.015aaNo significant difference when compared with the control (0% water).

Table 5: Formaldehyde level in the excipient samples.

Company Excipient Formaldehyde level (µg/g)A PVP K-30 NDa

B PVP K-30 NDa

C PVP K-30 3.51b

D PVP K-25 8.04E PEG 400 22.47F PEG 400 3.64b

G PEG 300 190.58aNot detected; bformaldehyde level<QL.

6 Journal of Analytical Methods in Chemistry

Formaldehyde was not detected in PVP K-30 samplesfrom the companies A and B. However, PVP samples (fromthe companies C and D) contained trace amount of form-aldehyde. Actually, there is no specific pharmacopoeial limitfor formaldehyde in PVP, but there is a general limit foraldehydes (500 ppm) which expressed as acetaldehyde [5, 6].

According to British Pharmacopoeia, the limit offormaldehyde in PEG is 15 ppm [5]. Both PEG 400 from thecompany E and PEG 300 from the company G had form-aldehyde levels exceeding the identified limit.

Although PVP K-25 from the companies C and D andPEG 400 from the company F contained trace levels offormaldehyde, however, such levels may cause critical drugproducts instability and degradation, especially whenexcipient/active pharmaceutical ingredient ratio is high,according to many literatures [1, 2, 4].

4. Conclusion

A SHS-GC-FID method was developed and validated for de-termination of formaldehyde in pharmaceutical excipients.Samples were simply prepared in headspace vials by addingacidified ethanol as a diluent and derivatization reagent. Afterthat, the vials were automatically moved to the incubator whereformaldehyde derivative was simultaneously formed andextracted. )e developed method was linear, specific, accurate,and precise over the specified range.)e limits of detection andquantificationwere 2.44 and 8.12µg/g, respectively.)emethodwas also simple and rapid, and it does not require sophisticatedinstrumentations or large amounts of solvents.)ismethodwasused to screen PEG and PVP samples for formaldehyde. )etested samples contained varying levels of it. So, the methodcould be valuable in selecting appropriate excipients and/orexcipient batches for pharmaceutical formulation. It is alsoimportant for selecting approved vendors of pharmaceuticalexcipients. In addition, it can be applied as a tool for testing thequality of pharmaceutical excipients routinely.

Conflicts of Interest

)e authors declare that they have no conflicts of interest.

Acknowledgments

)e authors greatfully acknowledge the Assistant Prof.Dr. Manal Daghestani, Dr. Faten Alsaka, Dr. GhassanAbochameh, and Ph.D. student Yamen Alsalka for helpingin carrying out analysis and data processing.

Supplementary Materials

Supplementary 1. Figure S1: representative GC-FID chro-matograms of specificity study.

Supplementary 2. Figure S2: GC-FID chromatogram of PEG400 sample spikedwith formaldehyde. DEM: diethoxymethane.

Supplementary 3. Figure S3: GC-FID chromatogramPVPK-30sample spiked with formaldehyde. DEM: diethoxymethane.

References

[1] A. S. Narang and S. H. Boddu, Excipient Applications inFormulation Design and Drug Delivery, Springer InternationalPublishing, Basel, Switzerland, 2015.

[2] M. Li, Organic Chemistry of Drug Degradation, Royal Societyof Chemistry, Cambridge, UK, 2012.

[3] R. P. Gullapalli and C. L. Mazzitelli, “Polyethylene glycols inoral and parenteral formulations—a critical review,” In-ternational Journal of Pharmaceutics, vol. 496, no. 2,pp. 219–239, 2015.

[4] K. K. Hotha, S. Roychowdhury, and V. Subramanian, “Drug-excipient interactions: case studies and overview of drugdegradation pathways,” American Journal of AnalyticalChemistry, vol. 7, no. 1, pp. 107–140, 2016.

[5] British Pharmacopeia, British Pharmacopeia Commission,London, UK, 2013.

[6] USP, <e United States Pharmacopeia, USP 39-NF 34, UnitedStates Pharmacopeial Convention, Rockville, MD, USA, 2016.

[7] S. T. Colgan, T. C. Zelesky, R. Chen et al., “Use of activatedcarbon in packaging to attenuate formaldehyde-induced andformic acid–induced degradation and reduce gelatin cross-linking in solid dosage forms,” Journal of PharmaceuticalSciences, vol. 105, no. 7, pp. 2027–2031, 2016.

[8] K. C. Waterman, W. B. Arikpo, M. B. Fergione et al., “N-methylation and N-formylation of a secondary amine drug(varenicline) in an osmotic tablet,” Journal of PharmaceuticalSciences, vol. 97, no. 4, pp. 1499–1507, 2008.

[9] G. Wang, J. D. Fiske, S. P. Jennings, F. P. Tomasella,V. A. Palaniswamy, and K. L. Ray, “Identification and controlof a degradation product in Avapro™ film-coated tablet: Lowdose formulation,” Pharmaceutical Development and Tech-nology, vol. 13, no. 5, pp. 393–399, 2008.

[10] M. Dousa, P. Gibala, J. Havlıcek, L. Placek, M. Tkadlecova, andJ. Brichac, “Drug-excipient compatibility testing—identificationand characterization of degradation products of phenylephrinein several pharmaceutical formulations against the commoncold,” Journal of Pharmaceutical and Biomedical Analysis, vol. 55,no. 5, pp. 949–956, 2011.

[11] Q. Zhong, S. Stowers, N. L. Segraves et al., “Degradation ofa pharmaceutical in HPLC grade methanol containing tracelevel formaldehyde,” Pharmaceutical Development andTechnology, vol. 18, no. 4, pp. 877–882, 2013.

[12] B. L. Williamson, A. J. Tomlinson, P. K. Mishra, G. J. Gleich,and S. Naylor, “Structural characterization of contaminantsfound in commercial preparations of melatonin: similaritiesto case-related compounds from L-tryptophan associatedwith eosinophilia-myalgia syndrome,” Chemical Research inToxicology, vol. 11, no. 3, pp. 234–240, 1998.

[13] P. K. Ragham and K. B. Chandrasekhar, “A rapid UPLC-UVmethod development and validation for the quantitativedetermination of formaldehyde using derivatization tech-nique,” International Journal of Research in PharmaceuticalSciences, vol. 6, no. 2, pp. 46–53, 2015.

[14] W.M. Haynes, CRCHandbook of Chemistry and Physics, CRCPress, Boca Raton, FL, USA, 93rd edition, 2012.

[15] J. N. Hemenway, T. C. Carvalho, V. M. Rao et al., “For-mation of reactive impurities in aqueous and neat poly-ethylene glycol 400 and effects of antioxidants and oxidationinducers,” Journal of Pharmaceutical Sciences, vol. 101, no. 9,pp. 3305–3318, 2012.

[16] M. A. del Barrio, J. Hu, P. Zhou, and N. Cauchon, “Simul-taneous determination of formic acid and formaldehyde inpharmaceutical excipients using headspace GC/MS,” Journal

Journal of Analytical Methods in Chemistry 7

of Pharmaceutical and Biomedical Analysis, vol. 41, no. 3,pp. 738–743, 2006.

[17] A. Teasdale, Genotoxic Impurities: Strategies for Identificationand Control, John Wiley & Sons, Hoboken, NJ, USA, 2011.

[18] S. Zali, F. Jalali, A. Es-haghi, and M. Shamsipur, “De-termination of free formaldehyde in vaccines and biologicalsamples using solid-phase microextraction coupled to GC–MS,” Journal of Separation Science, vol. 36, no. 24,pp. 3883–3888, 2013.

[19] Z. Li, B. M. Kozlowski, and E. P. Chang, “Analysis of aldehydesin excipients used in liquid/semi-solid formulations by gaschromatography–negative chemical ionization mass spec-trometry,” Journal of Chromatography A, vol. 1160, no. 1-2,pp. 299–305, 2007.

[20] Z. Li, L. K. Jacobus, W. P. Wuelfing, M. Golden, G. P. Martin,and R. A. Reed, “Detection and quantification of low-molecular-weight aldehydes in pharmaceutical excipientsby headspace gas chromatography,” Journal of Chromatog-raphy A, vol. 1104, no. 1-2, pp. 1–10, 2006.

[21] G. J. Manius, L. F. Wen, and D. Palling, “)ree approaches tothe analysis of trace formaldehyde in bulk and dosage formpharmaceuticals,” Pharmaceutical Research, vol. 10, no. 3,pp. 449–453, 1993.

[22] A. Nageswari, K. V. S. R. K. Reddy, and K. Mukkanti, “Low-level quantitation of formaldehyde in drug substance byHPLC–UV,” Chromatographia, vol. 75, no. 5-6, pp. 275–280,2012.

[23] S. Velankar, R. Lokhande, R. Yadav, and R. Pawar, “HPLCmethod development and validation for determination offormaldehyde and acetaldehyde traces in drug substance,”International Journal of Chemical and PharmaceuticalAnalysis, vol. 3, no. 4, 2016.

[24] B. Kolb and L. S. Ettre, Static Headspace-Gas Chromatogra-phy: <eory and Practice, John Wiley & Sons, New York, NY,USA, 2nd edition, 2006.

[25] C. F. Poole, Gas Chromatography, Elsevier, Waltham, MA,USA, 1st edition, 2012.

[26] J. Clayden, N. Greeves, and S. Warren, Organic Chemistry,Oxford University Press, New York, NY, USA, 2nd edition,2012.

[27] R. C. Rowe, P. J. Sheskey, and M. E. Quinn, Handbook ofPharmaceutical Excipients, Pharmaceutical Press, London,UK, 6th edition, 2009.

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