Reverse Engineering of Medicinal and Nutritional Products - Approaches Available for Generic Product Development

Page: [130 - 146] Pages: 17

  • * (Excluding Mailing and Handling)

Abstract

Pharmaceutical preparations contain at least one active pharmaceutical ingredient and a wide range of excipients, each with a defined pharmaceutical purpose. India is known as the pharmacy of the world (manufacturing generic drug products). The market demand of generic products is increasing exponentially throughout the Asian and African regions. To satisfy the general population needs and competition in the market, specific tools need to be there in the generic manufacturing unit that can fulfill the need of generic manufactures in cracking the branded medicinal and nutritional products. This review aims to present reverse engineering techniques that have been found beneficial in qualitative and quantitative analysis. The diversity of techniques and their uses in generic product development have been reviewed here. This was a supposed idea to provide the generic manufacturers with an analytical tool set that can make generic product development easier and provides several examples of excipients that have been identified to crack the drug composition.

Keywords: Reverse engineering, Deformulation, Analytical techniques, Generic Product development, Forensic evaluation.

Graphical Abstract

[1]
Kumar, A; Jain, PK; Pathak, PM Reverse engineering in product manufacturing: An overview. DAAAM International scientific book, 2013, 39, 665-78.
[http://dx.doi.org/10.2507/daaam.scibook.2013.39]
[2]
Borman, P; Elder, D. Q2 (R1) validation of analytical procedures. ICH Quality guidelines, 2017, 5, 127-66.
[3]
Narang, A.S.; Boddu, S.H. Excipient Applications in Formulation Design and Drug Delivery. In: Excipient Applications in Formulation Design and Drug Delivery; Springer: Cham, 2015; pp. 1-10.
[4]
ICH quality guidelines: An implementation guide;; Teasdale, A.; Elder, D.; Nims, R.W., Eds.; John Wiley & Sons City: New Jersey, 2017.
[http://dx.doi.org/10.1002/9781118971147]
[5]
Haleem, R.M.; Salem, M.Y.; Fatahallah, F.A.; Abdelfattah, L.E. Quality in the pharmaceutical industry – A literature review. Saudi Pharm. J., 2015, 23(5), 463-469.
[http://dx.doi.org/10.1016/j.jsps.2013.11.004] [PMID: 26594110]
[6]
Bellinvia, S.; Edwards, C.J. Explaining biosimilars and how reverse engineering plays a critical role in their development. Expert Opin. Drug Discov., 2020, 15(11), 1283-1289.
[http://dx.doi.org/10.1080/17460441.2020.1796627] [PMID: 32717155]
[7]
Koradia, V.S.; Chawla, G.; Bansal, A.K. Comprehensive characterisation of the innovator product: Targeting bioequivalent generics. J. Generic Med., 2005, 2(4), 335-346.
[http://dx.doi.org/10.1057/palgrave.jgm.4940086]
[8]
Baldrick, P. Pharmaceutical excipient development: The need for preclinical guidance. Regul. Toxicol. Pharmacol., 2000, 32(2), 210-218.
[http://dx.doi.org/10.1006/rtph.2000.1421] [PMID: 11067777]
[9]
Lanzarotta, A.; Kern, S.; Batson, J.; Falconer, T.M.; Fulcher, M.; Gaston, K.W.; Kimani, M.M.; Lorenz, L.; Morales-Garcia, F.; Ranieri, N.; Skelton, D.; Thatcher, M.D.; Toomey, V.M.; Voelker, S.; Witkowski, M.R. Evaluation of “Toolkit” consisting of handheld and portable analytical devices for detecting active pharmaceutical ingredients in drug products collected during a simultaneous nation-wide mail blitz. J. Pharm. Biomed. Anal., 2021, 203, 114183.
[http://dx.doi.org/10.1016/j.jpba.2021.114183] [PMID: 34098507]
[10]
Gillespie, T.A.; Winger, B.E. Mass spectrometry for small molecule pharmaceutical product development: A review. Mass Spectrom. Rev., 2011, 30(3), 479-490.
[http://dx.doi.org/10.1002/mas.20289] [PMID: 21500245]
[11]
Geoghegan, K.F.; Kelly, M.A. Biochemical applications of mass spectrometry in pharmaceutical drug discovery. Mass Spectrom. Rev., 2005, 24(3), 347-366.
[http://dx.doi.org/10.1002/mas.20019] [PMID: 15389851]
[12]
Baghel, U.S.; Singh, A.; Singh, D.; Sinha, M. Application of mass spectroscopy in pharmaceutical and biomedical analysis. In: Spectroscopic Analyses-Developments and Applications;; Intechopen: Linclon, 2017; pp. 105-21.
[http://dx.doi.org/10.5772/intechopen.70655]
[13]
Mortishire-Smith, R.J.; O’Connor, D.; Castro-Perez, J.M.; Kirby, J. Accelerated throughput metabolic route screening in early drug discovery using high-resolution liquid chromatography/quadrupole time-of-flight mass spectrometry and automated data analysis. Rapid Commun. Mass Spectrom., 2005, 19(18), 2659-2670.
[http://dx.doi.org/10.1002/rcm.2111] [PMID: 16124034]
[14]
Bruggink, C.; Jensen, D. Combining ion chromatography with mass spectrometry and inductively coupled plasma‐mass spectrometry: Annual review 2020. Anal. Sci. Adv., 2021, 2(3-4), 238-249.
[http://dx.doi.org/10.1002/ansa.202000120]
[15]
Chawla, R.K.; Gudhanti, S.N.; Kul, U.; Alavala, R.R. Development and validation of an inductively coupled plasma mass spectrometry method for estimation of elemental impurities in calcium acetate active pharmaceutical ingredient. Indian J. Pharm. Sci., 2021, 83(4), 830-837.
[16]
Sen, I; Shrivastava, D; Aggarwal, M; Khandal, RK Development of a validated method for quantitative analysis of heavy metals in herbal medicines using inductively coupled plasma mass spectrometry., 2021, 1, 487-502.
[17]
Diehl, B. Principles in NMR Spectroscopy. In: NMR Spectroscopy in Pharmaceutical Analysis;; Elsevier: Amsterdam, 2008; pp. 1-41.
[18]
Saraf, I.; Kushwah, V.; Weber, H.; Modhave, D.; Yeoh, T.; Paudel, A. Quantitative chemical profiling of commercial glyceride excipients via1H NMR spectroscopy. AAPS PharmSciTech, 2021, 22(1), 11.
[http://dx.doi.org/10.1208/s12249-020-01883-x] [PMID: 33270172]
[19]
Singh, S.; Roy, R. The application of absolute quantitative 1 H NMR spectroscopy in drug discovery and development. Expert Opin. Drug Discov., 2016, 11(7), 695-706.
[http://dx.doi.org/10.1080/17460441.2016.1189899] [PMID: 27187052]
[20]
Akçan, R. Yıldırım, M.Ş. Raman spectroscopy as a novel technology in forensic toxicological analyses. Curr. Anal. Chem., 2021, 17(8), 1082-1096.
[http://dx.doi.org/10.2174/1573411016999200602124328]
[21]
Khan, FN; Baig, MS; Nihalani, G; Imran, M; Deshingkar, N Formulation of generic atorvastatin calcium tablet by reverse engineering technique.,
[22]
Lemos, V.F.; Ortiz, R.S.; Limberger, R.P. Forensic analysis of anabolic steroids tablets composition using attenuated total reflection Fourier transform infrared microspectroscopy (µATR‐FTIR) mapping. J. Forensic Sci., 2021, 66(3), 837-845.
[http://dx.doi.org/10.1111/1556-4029.14671] [PMID: 33502006]
[23]
Mallah, M.A.; Sherazi, S.T.H.; Bhanger, M.I.; Mahesar, S.A.; Bajeer, M.A. A rapid Fourier-transform infrared (FTIR) spectroscopic method for direct quantification of paracetamol content in solid pharmaceutical formulations. Spectrochim. Acta A Mol. Biomol. Spectrosc., 2015, 141, 64-70.
[http://dx.doi.org/10.1016/j.saa.2015.01.036] [PMID: 25659814]
[24]
Wahr, J.A.; Tremper, K.K.; Samra, S.; Delpy, D.T. Near-infrared spectroscopy: Theory and applications. J. Cardiothorac. Vasc. Anesth., 1996, 10(3), 406-418.
[http://dx.doi.org/10.1016/S1053-0770(96)80107-8] [PMID: 8725427]
[25]
Malik, I.; Poonacha, M.; Moses, J.; Lodder, R.A. Multispectral imaging of tablets in blister packaging. AAPS PharmSciTech, 2001, 2(2), 38-44.
[http://dx.doi.org/10.1208/pt020209] [PMID: 14727884]
[26]
Meza, C.P.; Santos, M.A.; Romañach, R.J. Quantitation of drug content in a low dosage formulation by transmission near infrared spectroscopy. AAPS PharmSciTech, 2006, 7(1), E206-E214.
[http://dx.doi.org/10.1208/pt070129] [PMID: 28290044]
[27]
Yang, H.; Irudayaraj, J. Rapid determination of vitamin C by NIR, MIR and FT-Raman techniques. J. Pharm. Pharmacol., 2010, 54(9), 1247-1255.
[http://dx.doi.org/10.1211/002235702320402099] [PMID: 12356279]
[28]
Ebube, N.K.; Thosar, S.S.; Roberts, R.A.; Kemper, M.S.; Rubinovitz, R.; Martin, D.L.; Reier, G.E.; Wheatley, T.A.; Shukla, A.J. Application of near-infrared spectroscopy for nondestructive analysis of Avicel powders and tablets. Pharm. Dev. Technol., 1999, 4(1), 19-26.
[http://dx.doi.org/10.1080/10837459908984220] [PMID: 10027209]
[29]
Gökbulut, A. High Performance Thin Layer Chromatography (HPTLC) for the investigation of medicinal plants. Curr. Anal. Chem., 2021, 17(9), 1252-1259.
[http://dx.doi.org/10.2174/1573411016999200602124813]
[30]
Kumssa, L.; Layloff, T.; Hymete, A.; Ashenef, A. High performance thin layer chromatography (HPTLC) method development and validation for determination of doxycycline hyclate in capsule and tablet formulations. Acta Chromatogr., 2021, 34(3)
[31]
Ambati, P; Bala Krishna, P; Srinivasa Rao, Y; Varaprasada Rao, K; Deepthi, R. Instrumentation and future prospects of HPTLC-a.,
[32]
Liu, Y.; Victoria, J.; Wood, M.; Staretz, M.E.; Brettell, T.A. High Performance Thin-Layer Chromatography (HPTLC) data of Cannabinoids in ten mobile phase systems. Data Brief, 2020, 31, 105955.
[http://dx.doi.org/10.1016/j.dib.2020.105955] [PMID: 32676528]
[33]
Alam, P.; Salem-Bekhit, M.M.; Al-Joufi, F.A.; Alqarni, M.H.; Shakeel, F. Quantitative analysis of cabozantinib in pharmaceutical dosage forms using green RP-HPTLC and green NP-HPTLC methods: A comparative evaluation. Sustain. Chem. Pharm., 2021, 21, 100413.
[http://dx.doi.org/10.1016/j.scp.2021.100413]
[34]
Goyal, K.; Tomar, N.; Singh, A.P.; Sarin, R.K.; Shukla, S.K. Validation of an analytical method for the detection of ephedrine and its analogues in forensic samples using HPTLC–MS. J. Planar Chromatogr. Mod. TLC, 2020, 33(4), 397-404.
[http://dx.doi.org/10.1007/s00764-020-00049-6]
[35]
Abdelwahab, N.S.; Abdelrahman, M.M. Appraisal of the greenness profile of a chromatographic method for the simultaneous estimation of carbamazepine and oxcarbazepine, along with two potential impurities and three formulation excipients. RSC Advances, 2021, 11(14), 7790-7800.
[http://dx.doi.org/10.1039/D0RA10521J] [PMID: 35423303]
[36]
Forget, R.; Spagnoli, S. Excipient quantitation and drug distribution during formulation optimization. J. Pharm. Biomed. Anal., 2006, 41(3), 1051-1055.
[http://dx.doi.org/10.1016/j.jpba.2006.01.039] [PMID: 16487674]
[37]
Cooper, L.; Schafer, A.; Li, Y.; Cheng, H.; Medegan Fagla, B.; Shen, Z.; Nowar, R.; Dye, K.; Anantpadma, M.; Davey, R.A.; Thatcher, G.R.J.; Rong, L.; Xiong, R. Screening and reverse-engineering of estrogen receptor ligands as potent pan-filovirus inhibitors. J. Med. Chem., 2020, 63(19), 11085-11099.
[http://dx.doi.org/10.1021/acs.jmedchem.0c01001] [PMID: 32886512]
[38]
Zhang, Y.; Yao, S.; Zeng, H.; Song, H. Chiral separation of pharmaceuticals by high performance liquid chromatography. Curr. Pharm. Anal., 2010, 6(2), 114-130.
[http://dx.doi.org/10.2174/157341210791202636]
[39]
Hua, Y.; Wang, Z.; Wang, D.; Lin, X.; Liu, B.; Zhang, H.; Gao, J.; Zheng, A. Key factor study for generic long-acting PLGA microspheres based on a reverse engineering of vivitrol®. Molecules, 2021, 26(5), 1247.
[http://dx.doi.org/10.3390/molecules26051247] [PMID: 33669152]
[40]
Risley, D.S.; Yang, W.Q.; Peterson, J.A. Analysis of mannitol in pharmaceutical formulations using hydrophilic interaction liquid chromatography with evaporative light-scattering detection. J. Sep. Sci., 2006, 29(2), 256-264.
[http://dx.doi.org/10.1002/jssc.200500253] [PMID: 16524100]
[41]
Vogeser, M.; Parhofer, K. Liquid chromatography tandem-mass spectrometry (LC-MS/MS)--technique and applications in endocrinology. Exp. Clin. Endocrinol. Diabetes, 2007, 115(9), 559-570.
[http://dx.doi.org/10.1055/s-2007-981458] [PMID: 17943689]
[42]
Shao, Y.; Li, T.; Liu, Z.; Wang, X.; Xu, X.; Li, S.; Xu, G.; Le, W. Comprehensive metabolic profiling of Parkinson’s disease by liquid chromatography-mass spectrometry. Mol. Neurodegener., 2021, 16(1), 4.
[http://dx.doi.org/10.1186/s13024-021-00425-8] [PMID: 33485385]
[43]
Urban, P.L. Quantitative mass spectrometry: An overview. Philos. Trans.- Royal Soc., Math. Phys. Eng. Sci., 2016, 374(2079), 20150382.
[http://dx.doi.org/10.1098/rsta.2015.0382] [PMID: 27644965]
[44]
Gas Chromatography; Poole, C., Ed.; Elsevier: Amsterdam, 2012.
[45]
Hou, M.; Ren, H.; Cheng, W.; Li, L.; Zhang, S.; Chen, Y.; Yu, C.; Li, F.; Tian, S.; Deng, Z. Development of a headspace-gas chromatography/mass spectrometry method based on matrix-matched calibration for evaluating VOC content, characterization, source, and risk in RO membrane. Polym. Test., 2022, 107, 107474.
[http://dx.doi.org/10.1016/j.polymertesting.2022.107474]
[46]
Bell, S.E.J.; Thorburn Burns, D.; Dennis, A.C.; Matchett, L.J.; Speers, J.S. Composition profiling of seized ecstasy tablets by Raman spectroscopy. Analyst (Lond.), 2000, 125(10), 1811-1815.
[http://dx.doi.org/10.1039/b005662f] [PMID: 11070550]
[47]
Fu, X.; Zhong, L.; Cao, Y.; Chen, H.; Lu, F. Quantitative analysis of excipient dominated drug formulations by Raman spectroscopy combined with deep learning. Anal. Methods, 2021, 13(1), 64-68.
[http://dx.doi.org/10.1039/D0AY01874K] [PMID: 33305762]
[48]
de Oliveira Penido, C.A.F.; Pacheco, M.T.T.; Lednev, I.K.; Silveira, L., Jr Raman spectroscopy in forensic analysis: Identification of cocaine and other illegal drugs of abuse. J. Raman Spectrosc., 2016, 47(1), 28-38.
[http://dx.doi.org/10.1002/jrs.4864]
[49]
Sbahi, A.; Abdelwahed, W.; Sakar, A.A. A new flame aas application for magnesium determination in solid pharmaceutical preparations as an active ingredient and an excipient. Int. Res. J. Pure Appl. Chem., 2020.
[http://dx.doi.org/10.9734/irjpac/2020/v21i2330305]
[50]
dos Santos, M.K.; de Cassia Mariotti, K.; Kahmann, A.; Anzanello, M.J.; Ferrão, M.F.; de Araújo Gomes, A.; Limberger, R.P.; Ortiz, R.S. Comparison between counterfeit and authentic medicines: A novel approach using differential scanning calorimetry and hierarchical cluster analysis. J. Pharm. Biomed. Anal., 2019, 166, 304-309.
[http://dx.doi.org/10.1016/j.jpba.2019.01.029] [PMID: 30685655]
[51]
Berneira, L.M.; de Freitas, S.C.; da Silva, C.C.; Machado, A.M.; de Pereira, C.M.P.; dos Santos, M.A.Z. Application of differential scanning calorimetry in the analysis of apprehended formulations of anabolic androgenic steroids. Forensic Sci. Int., 2019, 296, 15-21.
[http://dx.doi.org/10.1016/j.forsciint.2018.12.022] [PMID: 30641440]
[52]
Calvino, M.M.; Lisuzzo, L.; Cavallaro, G.; Lazzara, G.; Milioto, S. Non-isothermal thermogravimetry as an accelerated tool for the shelf-life prediction of paracetamol formulations. Thermochim. Acta, 2021, 700, 178940.
[http://dx.doi.org/10.1016/j.tca.2021.178940]
[53]
Radecki, A. Wesołowski, M. Studies on use of differential thermal and thermogravimetric techniques for checking compositions of some drug formulations. J. Therm. Anal., 1979, 17(1), 73-80.
[http://dx.doi.org/10.1007/BF02156599]
[54]
Giannini, C.; Ladisa, M.; Altamura, D.; Siliqi, D.; Sibillano, T.; De Caro, L. X-ray diffraction: A powerful technique for the multiple-length-scale structural analysis of nanomaterials. Crystals (Basel), 2016, 6(8), 87.
[http://dx.doi.org/10.3390/cryst6080087]
[55]
Zhu, Q.; Scriba, G.K.E. Analysis of small molecule drugs, excipients and counter ions in pharmaceuticals by capillary electromigration methods – recent developments. J. Pharm. Biomed. Anal., 2018, 147, 425-438.
[http://dx.doi.org/10.1016/j.jpba.2017.06.063] [PMID: 28711220]
[56]
Kumar, M.; Bhatia, R.; Rawal, R.K. Applications of various analytical techniques in quality control of pharmaceutical excipients. J. Pharm. Biomed. Anal., 2018, 157, 122-136.
[http://dx.doi.org/10.1016/j.jpba.2018.05.023] [PMID: 29787965]
[57]
Ribeiro, M.M.A.C.; Prado, A.A.; Domingues Batista, A.; Alejandro Abarza Munoz, R.; Mathias Richter, E. Rapid method for simultaneous determination of ascorbic acid and zinc in effervescent tablets by capillary zone electrophoresis with contactless conductivity detection. J. Sep. Sci., 2019, 42(3), 754-759.
[http://dx.doi.org/10.1002/jssc.201801042] [PMID: 30488578]
[58]
Costa, B.M.C.; Prado, A.A.; Oliveira, T.C.; Bressan, L.P.; Munoz, R.A.A.; Batista, A.D.; da Silva, J.A.F.; Richter, E.M. Fast methods for simultaneous determination of arginine, ascorbic acid and aspartic acid by capillary electrophoresis. Talanta, 2019, 204, 353-358.
[http://dx.doi.org/10.1016/j.talanta.2019.06.017] [PMID: 31357304]
[59]
Tavares, M.F.M.; Jager, A.V.; Silva, C.L.; Moraes, E.P.; Pereira, E.A.; Lima, E.C.; Fonseca, F.N.; Tonin, F.G.; Micke, G.A.; Santos, M.R.; Oliveira, M.A.L.; Moraes, M.L.L.; Kampen, M.H.; Fujiya, N.M. Applications of capillary electrophoresis to the analysis of compounds of clinical, forensic, cosmetological, environmental, nutritional and pharmaceutical importance. J. Braz. Chem. Soc., 2003, 14(2), 281-290.
[http://dx.doi.org/10.1590/S0103-50532003000200016]
[60]
Roscher, J.; Posch, T.N.; Pütz, M.; Huhn, C. Forensic analysis of mesembrine alkaloids in Sceletium tortuosum by nonaqueous capillary electrophoresis mass spectrometry. Electrophoresis, 2012, 33(11), 1567-1570.
[http://dx.doi.org/10.1002/elps.201100683] [PMID: 22736358]
[61]
Troška, P. Poboży, E.; Némethová, Z.; Masár, M. Determination of commonly used excipients in pharmaceutical preparations by microchip electrophoresis with conductivity detection. Chromatographia, 2019, 82(4), 741-748.
[http://dx.doi.org/10.1007/s10337-019-03691-3]
[62]
Troška, P.; Hradski, J. Chropeňová, L.; Szucs, R.; Masár, M. Potential of microchip electrophoresis in pharmaceutical analysis: Development of a universal method for frequently prescribed nonsteroidal anti-inflammatory drugs. J. Chromatogr. A, 2021, 1654, 462453.
[http://dx.doi.org/10.1016/j.chroma.2021.462453] [PMID: 34392125]
[63]
Zeid, A.M.; Kaji, N.; Nasr, J.J.M.; Belal, F.; Walash, M.I.; Baba, Y. Determination of baclofen and vigabatrin by microchip electrophoresis with fluorescence detection: Application of field-enhanced sample stacking and dynamic pH junction. New J. Chem., 2018, 42(12), 9965-9974.
[http://dx.doi.org/10.1039/C8NJ00829A]
[64]
Verma, G.; Mishra, M. Development and optimization of UV-Vi’s spectroscopy–A review. World J. Pharm. Res., 2018, 7(11), 1170-1180.
[65]
Jani, B.R.; Shah, K.V.; Kapupara, P.P. Development and validation of UV spectroscopic first derivative method for simultaneous estimation of dapagliflozin and metformin hydrochloride in synthetic mixture. J Bioequivalent., 2015, 1(1), 102.
[66]
Behera, S.; Ghanty, S.; Ahmad, F.; Santra, S.; Banerjee, S. UV-visible spectrophotometric method development and validation of assay of paracetamol tablet formulation. J. Anal. Bioanal. Tech., 2012, 3(6), 151-157.
[http://dx.doi.org/10.4172/2155-9872.1000151]
[67]
Redasani, V.K.; Patel, P.R.; Marathe, D.Y.; Chaudhari, S.R.; Shirkhedkar, A.A.; Surana, S.J. A review on derivative UV-spectrophotometry analysis of drugs in pharmaceutical formulations and biological samples review. J. Chil. Chem. Soc., 2018, 63(3), 4126-4134.
[http://dx.doi.org/10.4067/s0717-97072018000304126]
[68]
Nataraj, K.S.; Charya, S.R.; Goud, E.S.; Ramanjineyulu, S.S. Simple quantitative method development and validation of valsartan in pure form and pharmaceutical dosage forms by UV–spectroscopy. Int. J. Pharma Bio Sci., 2011, 1(2)
[69]
Kaur, I.; Wakode, S.; Pal Singh, H. Development and validation of stability indicating UV spectroscopic method for determination of canagliflozin in bulk and pharmaceutical dosage form. Pharm. Methods, 2016, 7(1), 63-69.
[http://dx.doi.org/10.5530/phm.2016.7.10]
[70]
Kulkarni, A.A.; Vaidya, I.S. Flow injection analysis: An overview. J Crit Rev., 2015, 2, 19-24.
[71]
Waseem, A.; Yaqoob, M.; Nabi, A. Analytical applications of flow injection chemiluminescence for the determination of pharmaceuticals–a review. Curr. Pharm. Anal., 2013, 9(4), 363-395.
[http://dx.doi.org/10.2174/15734129113099990002]
[72]
Trojanowicz, M. Kołacińska, K. Recent advances in flow injection analysis. Analyst (Lond.), 2016, 141(7), 2085-2139.
[http://dx.doi.org/10.1039/C5AN02522B] [PMID: 26906258]
[73]
Costa, B.E.; Rezende, H.P.; Tavares, L.Q.; Coelho, L.M.; Coelho, N.M.; Sousa, P.A.; Néri, T.S. Application of Flow-Injection Spectrophotometry to Pharmaceutical and Biomedical Analyses. In: Spectroscopic Analyses—Developments and Applications;; Intechopen: Linclon, 2017; pp. 193-212.
[http://dx.doi.org/10.5772/intechopen.70160]
[74]
Shafi, N.; Siddiqui, F.A.; Naseem, H.; Sher, N.; Zubair, A.; Hussain, A.; Sial, A.A.; Baig, M.T. An overview of analytical determination of diltiazem, cimetidine, ranitidine, and famotidine by UV spectrophotometry and HPLC technique. J. Chem., 2013, 2013, 1-16.
[http://dx.doi.org/10.1155/2013/184948]
[75]
Solich, P.; Polydorou, C.K.; Koupparis, M.A.; Efstathiou, C.E. Automated flow-injection spectrophotometric determination of catecholamines (epinephrine and isoproterenol) in pharmaceutical formulations based on ferrous complex formation. J. Pharm. Biomed. Anal., 2000, 22(5), 781-789.
[http://dx.doi.org/10.1016/S0731-7085(00)00291-0] [PMID: 10815721]