Journal of Pharmacy And Bioallied Sciences
Journal of Pharmacy And Bioallied Sciences Login  | Users Online: 1520  Print this pageEmail this pageSmall font sizeDefault font sizeIncrease font size 
    Home | About us | Editorial board | Search | Ahead of print | Current Issue | Past Issues | Instructions | Online submission




 
ORIGINAL ARTICLE
Year : 2010  |  Volume : 2  |  Issue : 1  |  Page : 32-37 Table of Contents     

Development and validation of a headspace gas chromatographic method for the determination of residual solvents in arterolane (RBx11160) maleate bulk drug


Analytical Research and Development-New Drug Discovery Research, Ranbaxy Research Laboratories, Gurgaon, Haryana-122 001, India

Date of Submission22-Jan-2010
Date of Decision15-Feb-2010
Date of Acceptance25-Feb-2010
Date of Web Publication23-Apr-2010

Correspondence Address:
Abhishek Gupta
Analytical Research and Development-New Drug Discovery Research, Ranbaxy Research Laboratories, Gurgaon, Haryana-122 001
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0975-7406.62706

Rights and Permissions
   Abstract 

Objective : Arterolane maleate is an antimalarial drug currently under Phase III clinical evaluation, and presents a simple, economical and scalable synthesis, and does not suffer from safety problems. Arterolane maleate is more active than artemisinin; and is cheap to produce. It has a longer lifetime in the plasma, so it stays active longer in the body. To provide quality control over the manufacture of any API, it is essential to develop highly selective analytical methods. In the current article we are reporting the development and validation of a rapid and specific Head space gas chromatographic (HSGC) method for the determination of organic volatile impurities (residual solvents) in Arterolane Maleate bulk drug. Materials and Methods : The method development and its validation were performed on Perkin Elmer's gas chromatographic system equipped with Flame Ionization detector and head space analyzer. The method involved a thermal gradient elution of ten residual solvents present in arterolane maleate salt in RTx-624, 30 m Χ 0.32 mm, 1.8 μ column using nitrogen gas as a carrier. The flow rate was 0.5 ml/min and flame ionization detector (FID) was used. Results : During method validation, parameters such as precision, linearity, accuracy, limit of quantification and detection and specificity were evaluated, which remained within acceptable limits. Conclusions : The method has been successfully applied for the quantification of the amount of residual solvents present in arterolane maleate bulk drug.The method presents a simple and reliable solution for the routine quantitative analysis of residual solvents in Arterolane maleate bulk drug.

Keywords: Arterolane maleate; headspace gas chromatography; method development; residual solvents; validation


How to cite this article:
Gupta A, Singh Y, Srinivas KS, Jain G, Sreekumar V B, Semwal VP. Development and validation of a headspace gas chromatographic method for the determination of residual solvents in arterolane (RBx11160) maleate bulk drug. J Pharm Bioall Sci 2010;2:32-7

How to cite this URL:
Gupta A, Singh Y, Srinivas KS, Jain G, Sreekumar V B, Semwal VP. Development and validation of a headspace gas chromatographic method for the determination of residual solvents in arterolane (RBx11160) maleate bulk drug. J Pharm Bioall Sci [serial online] 2010 [cited 2019 May 24];2:32-7. Available from: http://www.jpbsonline.org/text.asp?2010/2/1/32/62706

The need for a rapid and reliable method for the determination of residual solvents has become significant due to the toxicity of residual solvents in drug substances and drug products. [1] The determination of residual solvents in drug substances, excipients or drug products is known to be one of the most difficult and demanding analytical tasks in the pharmaceutical industry. Furthermore, determination of the polar residual solvents in pharmaceutical preparations is still an analytical challenge mainly because these compounds are quite difficult to remove from water or polar solvents. [2] Many pharmaceutical products have to be analyzed for residual solvents at different stages of their development (raw materials, intermediate products and final product). Organic solvents such as ethanol, dichloromethane, hexanes, n-heptane, etc. are frequently used in the pharmaceutical industry. The manufacturing of new active pharmaceutical ingredients (APIs) under Good manufacturing practices (GMP) conditions demands adequate control of quality of the different ingredients used in the synthesis. Organic residual solvents have therefore to be controlled during any GMP synthesis. Headspace gas chromatography (HSGC) is the most favored technique for the analysis of volatiles and semivolatile organics in solid, liquid and gas samples. [3],[4],[5],[6],[7]

Arterolane maleate [Figure 1] is an antimalarial drug currently under Phase III clinical evaluation, and presents a simple, economical and scalable synthesis, and does not suffer from safety problems. [8] Arterolane maleate contains a type of bridge that is considered important for its activity (it generates radicals that target proteins in the parasite), and was engineered with the bulky adamantane group next to it to protect the peroxide bridge. [9] Arterolane maleate is more active than artemisinin; it has sufficient solubility to be administered orally, and is cheap to produce. It has a longer lifetime in the plasma, so it stays active longer in the body. [10],[11],[12] To provide quality control over the manufacture of any API, it is essential to develop highly selective analytical methods. HSGC is one of the most widely accepted techniques used to monitor the residual solvents present in APIs. Therefore, a highly selective, rapid and linear HSGC method was developed for the quantification of a total of 10 residual solvents which are used during the synthesis and manufacturing of arterolane maleate in accordance with International Conference on Harmonization (ICH) guidelines. [13],[14]


   Materials and Methods Top


Chemical and reagents

Arterolane maleate was obtained from NCE Scaleup division of Ranbaxy Research Laboratories, Gurgaon, India. Milli Q water was obtained from inhouse Milli Q water plant. N,N-dimethyl formamide, sodium chloride, pentane, ethanol, 2-methylpentane, dichloromethane, 3-methylpentane, n-hexane, methylcyclopentane, cyclohexane, benzene and n-heptane were purchased from Fluka Chemical Co., Inc. (Milwaukee, WI, USA).

Apparatus and chromatographic conditions

The analysis for the determination of residual solvents and its validation was performed on Perkin Elmer's gas chromatograph Clarus 500 equipped with turbomatrix headspace sampler and a flame ionization detector (FID).

RTx-624 with dimensions of 30.0 m Χ 0.32 mm using a 1.8 μm capillary column, from Restek Corporations was used for the validation. The final validated HSGC method for the separation of residual solvents used a flow rate of 0.5 ml/min. Oven temperature was maintained at 40C for 20 min, and then a linear thermal gradient of 15C/min to 200C was used with a final hold of 5 min. Total run time was 35.0 min. Nitrogen was used as a carrier gas at a constant flow rate of 0.5 ml/min. The headspace and detector conditions used for the analysis are outlined in [Table 1] and [Table 2], respectively.

Preparation of standard and sample vials

A common standard stock solution in N,N-dimethylformamide containing all the known residual solvents of arterolane maleate API (i.e., pentane, ethanol, 2-methylpentane, dichloromethane, 3-methylpentane, n-hexane, methylcyclopentane, cyclohexane, benzene and n-heptane) was prepared in such a way that it has a final concentration of 50 μg/g for pentane, 2-methylpentane, 3-methylpentane, n-hexane, cyclohexane, methylcyclopentane; 3000 μg/g for ethanol, 375μg/g for dichloromethane, 1500 μg/g for n-heptane and 2 μg/g for benzene. The standard vial was prepared with 0.2 ml of the standard solution and the sample vials were prepared with approximately 0.1 g of sample with 0.2 ml N,N-dimethylformamide as diluent. Water and sodium chloride were added in both the sample and standard vials in a ratio of 2 : 1, respectively.

Method validation

The method validation was done by evaluating specificity, limit of detection (LOD) and limit of quantitation (LOQ), linearity, accuracy, repeatability, and method precision of residual solvents as indicated in the ICH guideline Q2B 'Validation of Analytical Procedures: Methodology.' [15]

Specificity

Arterolane API sample was spiked with pentane, ethanol, 2-methylpentane, dichloromethane, 3-methylpentane, n-hexane, methylcyclopentane, cyclohexane, benzene and n-heptane individually and each sample was chromatographed to examine interference, if any, of the residual solvents' peak with each other.

Linearity

The linearity of the method was determined by making injections of each residual solvent over the range of limit of quantification (LOQ) to 200% of the standard concentration as mentioned earlier.

System precision

Six vials of standard solution were prepared and chromatographed in the GC system.

Method precision

A single batch of arterolane (RBx11160) API was prepared six times and analyzed by the proposed method.

Detection and quantification limits

The LODs of residual solvents in arterolane (RBx11160) maleate were determined based on signal-to-noise ratio of 3 : 1. The LOQs of residual solvents were determined based on signal-to-noise ratio 10 : 1. Six replicates were performed at each level.

Accuracy

Known amount of sample (about 100 mg) was taken separately in nine different vials and spiked with known quantities of pentane, ethanol, 2-methylpentane, dichloromethane, 3-methylpentane, n-hexane, methylcyclopentane, cyclohexane, benzene and n-heptane at three different levels, in triplicate.

System suitability

A system suitability criterion was taken to be the resolution between the critical pairs, i.e., 2-methylpentane and dichloromethane. The system suitability was evaluated by injecting the standard solution on various days before starting the any exercise during validation study.


   Results and Discussion Top


Method development

An understanding of the nature of the various residual solvents present in API is the foremost prerequisite for successful method development in HSGC. In addition, successful method development should result in a fast, simple and time efficient method that is capable of being utilized in a manufacturing setting. Following were the stepwise strategies for the method development in our case.

Column selection

The primary goal of column selection was to resolve a total of 10 residual solvents (i.e., pentane, ethanol, 2-methylpentane, dichloromethane, 3-methylpentane, n-hexane, methylcyclopentane, cyclohexane, benzene and n-heptane) which were used during the synthesis and manufacturing of arterolane maleate. Several columns were initially investigated to finalize a single method for the separation and quantitation of solvents. Wall-coated capillary columns of various brands with a variety of phases and dimensions have been investigated, e.g., column A (30 m length, 0.32 mm i.d. with a stationary phase of 6% cynopropyl phenyl and 94% dimethyl polysiloxane film of 3.0 μ), RTx-624 (30 m length, 0.32 mm i.d. with a stationary phase of 6% cynopropyl phenyl and 94% dimethyl polysiloxane film of 1.8 μ). In the above column, the response was found to be comparatively lower and peak shapes were found to be unsatisfactory. Also, there was a problem in resolving the closely related peaks specially 2-methylpentane and dichloromethane. Therefore, RTx-624 with dimensions of 30 m Χ 0.32 mm, 1.8 μ proved to be the best column that could fulfill all the needs of the method, i.e., higher sensitivity, shorter runtime and higher resolution between the critical pairs.

Thermal program and thermal gradient

A linear thermal gradient was chosen to provide elution of the solvents' peak during the isothermal segment of the chromatographic run for better quantification. An initial hold of 20 min at 40C and a linear thermal gradient to 200C at 15C/min was found to give the best peak shape and retention without affecting the resolution. The critical pair under these conditions was 2-methyl pentane and dichloromethane for which resolution was achieved more than 2.

Headspace method optimization

The headspace method was optimized in such a way that maximum amount of the solvents present in the sample get evaporated for the detection. For this the standard and sample vials were heated at 60-95C for 20-30 min with constant shaking. A combination of sample vial heating at 75C with 20 min shaking was found to be suitable for getting a good response. [Table 1] shows the complete headspace condition.

Method validation

Specificity

The relative retention time of the all-residual solvents indicated that they were well separated from each other [Table 3]. A typical chromatogram of standard solution is shown in [Figure 2].

Linearity

The FID detector response was shown to be linear over this range with correlation coefficients (R2 ) higher than 0.99 [Table 4].

System precision

Results indicate an acceptable level of precision for the analytical system [Table 5]. The % relative standard deviation (%RSD) of area obtained from six standard vials was calculated to show the system precision. An acceptance criterion for system precision was taken to be not more than (NMT) 8% for six vials.

Method precision

The %RSD values indicate that the method has an acceptable level of precision. The %RSD values of area obtained from six sample vials were calculated to show the method precision [Table 6]. An acceptance criterion for method precision was taken to be NMT 10% for six preparations.

Detection and quantification limits

[Table 7] and [Table 8] show the quantification and detection limits, respectively, for the samples.

Accuracy

The accuracy was evaluated by the % recoveries of residual solvents spiked in the sample. An acceptance criterion for accuracy was that the recovery should be in the range of 80-120%. The recoveries of residual solvents ranged between 93.06 and 106.6%. Results indicate that the method has an acceptable level of accuracy [Table 9].

System suitability

Using the system suitability software, resolution between 2-methylpentane and dichloromethane was calculated. The criterion for system suitability was that the resolution between critical pair mentioned above should not be less than 1.5 and it was found well above the minimum passing limit [Table 10].


   Conclusion Top


A single, rapid and highly selective HSGC method was developed and validated for the quantification of residual solvents present in arterolane maleate bulk drug through an understanding of the synthetic process, nature of solvents and nature of stationary phases of columns. The residual solvents pentane, ethanol, 2-methylpentane, n-heptane, 3-methylpentane, n-hexane, methylcyclopentane, cyclohexane, benzene and dichloromethane were determined. The method was shown to be specific for arterolane maleate and was applied successfully to monitor and control these solvents on a manufacturing level. The method was found to be applicable for the routine analysis of the arterolane maleate in pharmaceutical industry.


   Acknowledgments Top


The author would like to thank Dr. Gyan Chand Yadav (NCE Scaleup Department, Ranbaxy Research Lab) for supplying samples of arterolane maleate and Ms. Aarti Sharma (Jaipur National University, Jaipur, India) for her contribution in restructuring the article.

 
   References Top

1.Sugimoto M, Suzuki H, Akimoto K, Kuchiki A, Nakagawa H. Determination of residual solvents in drug substances by gas chromatography with thermal desorption cold trap injection. Chem Pharm Bull 1995;43:2010-3.  Back to cited text no. 1      
2.B'Hymer C. Residual solvent testing: A review of gas chromatographic and alternative techniques. Pharm Res 2003;23:337-44.  Back to cited text no. 2      
3.Camarasu CC. Unknown residual solvents identification in drug products by headspace solid phase microextraction gas chromatography-mass spectrometry. J Chromatographia 2002;56:S131-5.  Back to cited text no. 3      
4.Raghani AR. High speed gas chromatographic analysis of solvents in pharmaceutical using solid phase microextraction. J Pharm Biomed Anal 2002;29:507-18.  Back to cited text no. 4      
5.Coran SA, Giannellini V, Furlanetto S, Bambagiotti-Alberti M, Pinzauti S. Improving Gas chromatographic determination of residual solvents in pharmaceuticals by the combined use of head space solid-phase microextraction and isotopic solution. J Chromatogr A 2001;915:209-16.  Back to cited text no. 5      
6.Rocheleau MJ, Titley M, Bolduc J. Measuring residual solvents in pharmaceutical samples using fast gas chromatography techniques. J Chromatogr B Analyt Technol Biomed Life Sci 2004;805:77-86.   Back to cited text no. 6      
7.Legrand S, Dugay J, Vial J. Use of solid-phase microextraction coupled with gas chromatography for the determination of residual solvents in pharmaceuticals in pharmaceutical products. J Chromatogr A 2003;999:195-201.  Back to cited text no. 7      
8.Walawalkar MG. A new antimalarial candidate. Curr Sci 2004;87:1035-7.  Back to cited text no. 8      
9.Kaiser M, Wittlin S, Nehrbass-Stuedli A, Dong Y, Wang X, Hemphill A, et al. Peroxide bond-dependent antiplasmodial specificity of artemisinin and OZ277 (RBx11160). Antimicrob Agents Chemother 2007;51:2991-3.  Back to cited text no. 9      
10.Kreidenweiss A, Mordmόller B, Krishna S, Kremsner PG. Antimalarial activity of a synthetic endoperoxide (RBx-11160/OZ277) against Plasmodium falciparum isolates from Gabon. Antimicrob Agents Chemother 2006;50:1535-7.  Back to cited text no. 10      
11.Uhlemann AC, Wittlin S, Matile H, Bustamante LY, Krishna S. Mechanism of antimalarial action of the synthetic trioxolane RBX11160 (OZ277). Antimicrob Agents Chemother 2007;51:667-72.  Back to cited text no. 11      
12.Maerki S, Brun R, Charman SA, Dorn A, Matile H, Wittlin S. In vitro assessment of the pharmacodynamic properties and the partitioning of OZ277/RBx-11160 in cultures of Plasmodium falciparum. J Antimicrob Chemother 2006;58:52-8.  Back to cited text no. 12      
13.International Conference on Harmonization, Impurities in new drug substances, Q3A (R2), 2006.  Back to cited text no. 13      
14.Reddy P, Reddy MS. Residual Solvents determination by HS-GC with flame ionization detector in omeprazole pharmaceutical formulations. Int J Pharm Tech Res 2009;1:230-4.  Back to cited text no. 14      
15.International Conference on Harmonization, Validation of Analytical Procedures: Methodology, Q2B, 1996.  Back to cited text no. 15      


    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10]


This article has been cited by
1 Novel anti-malarial combinations and their toxicity
Brian Angus
Expert Review of Clinical Pharmacology. 2014; 7(3): 299
[Pubmed] | [DOI]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    Abstract
    Materials and Me...
    Results and Disc...
    Conclusion
    Acknowledgments
    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed5494    
    Printed225    
    Emailed2    
    PDF Downloaded385    
    Comments [Add]    
    Cited by others 1    

Recommend this journal