Stability of pharmaceutical salts in solid oral dosage forms

References

• Wells JI. Pharmaceutical preformulation: the physicochemical properties of drug substances. Chichester, UK: E. Horwood; 1988.
   Google Scholar
• Lipinski CA. Drug-like properties and the causes of poor solubility and poor permeability. J Pharmacol Toxicol Methods 2000;44:235–49.
   PubMed Web of Science ®Google Scholar
• Lipinski CA, Lombardo F, Dominy BW, Feeney PJ. Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings1. Adv Drug Deliv Rev 2001;46:3–26.
   PubMed Web of Science ®Google Scholar
• Nelson E. Solution rate of theophylline salts and effects from oral administration. J Am Pharm Assoc 1957;46:607–14.
   Google Scholar
• Berge SM, Bighley LD, Monkhouse DC. Pharmaceutical salts. J Pharm Sci 1977;66:1–19.
   PubMed Web of Science ®Google Scholar
• Saal C, Becker A. Pharmaceutical salts: a summary on doses of salt formers from the Orange Book. Eur J Pharm Sci 2013;49:614–23.
   PubMed Web of Science ®Google Scholar
• Zhang GG, Law D, Schmitt EA, Qiu Y. Phase transformation considerations during process development and manufacture of solid oral dosage forms. Adv Drug Deliv Rev 2004;56:371–90.
   PubMed Web of Science ®Google Scholar
• Nie H, Mo H, Zhang M, et al. Investigating the interaction pattern and structural elements of a drug–polymer complex at the molecular level. Mol Pharm 2015;12:2459–68.
   PubMed Web of Science ®Google Scholar
• Michael BM, David JWG, and P. Heinrich S. The physicochemical background: fundamentals of ionic equilibria. In: Heinrich Stahl P, ed. Pharmaceutical salts: properties, selection, and use. 2nd revised edn. Weinheim, Germany: Wiley, John & Sons; 2011.
   Google Scholar
• Loudon GM. Acids and bases. The curved-arrow notation. Organic chemistry. Colorado, USA: Roberts and Company; 2009:87–121.
   Google Scholar
• Clayden J, Greeves N, Warren S. Acid, base, and pKa. Organic chemistry. Oxford, UK: OUP Oxford; 2012:182–210.
   Google Scholar
• Towler CS, Li T, Wikström H, et al. An investigation into the influence of counterion on the properties of some amorphous organic salts. Mol Pharm 2008;5:946–55.
   PubMed Web of Science ®Google Scholar
• Kelder J, Funke C, De Boer T, et al. A comparison of the physicochemical and biological properties of mirtazapine and mianserin. J Pharm Pharmacol 1997;49:403–11.
   PubMed Web of Science ®Google Scholar
• Haynes WM. CRC handbook of chemistry and physics. 93rd edn. Florida, USA: Taylor & Francis; 2012.
   Google Scholar
• Rowe RC, Sheskey PJ, Quinn ME, Association AP. Handbook of pharmaceutical excipients. Illinois, USA: Pharmaceutical Press; 2009.
   Google Scholar
• Ismail Mohamed AEM. Acid–base equilibria of diazepam and prazepam in montmorillonite suspensions. Talanta 1998;46:951–9.
   PubMed Web of Science ®Google Scholar
• Gallardo V, Zurita L, Ontiveros A, Durán JDG. Interfacial properties of barium sulfate suspensions. Implications in their stability. J Pharm Sci 2000;89:1134–42.
   PubMed Web of Science ®Google Scholar
• Chen X, Morris KR, Griesser UJ, et al. Reactivity differences of indomethacin solid forms with ammonia gas. J Am Chem Soc 2002;124:15012–19.
   PubMed Web of Science ®Google Scholar
• Nie H, Liu Z, Marks BC, et al. Analytical approaches to investigate salt disproportionation in tablet matrices by Raman spectroscopy and Raman mapping. J Pharm Biomed Anal 2016;118:328–37.
   PubMed Web of Science ®Google Scholar
• Nie H, Xu W, Ren J, et al. Impact of metallic stearates on disproportionation of hydrochloride salts of weak bases in solid-state formulations. Mol Pharm 2016;13:3541–52.
   PubMed Web of Science ®Google Scholar
• Sarma B, Nath NK, Bhogala BR, Nangia A. Synthon competition and cooperation in molecular salts of hydroxybenzoic acids and aminopyridines. Cryst Growth Des 2009;9:1546–57.
   Web of Science ®Google Scholar
• Li ZJ, Abramov Y, Bordner J, et al. Solid-state acid–base interactions in complexes of heterocyclic bases with dicarboxylic acids: crystallography, hydrogen bond analysis, and 15N NMR spectroscopy. J Am Chem Soc 2006;128:8199–210.
   PubMed Web of Science ®Google Scholar
• Childs SL, Stahly GP, Park A. The salt–cocrystal continuum: the influence of crystal structure on ionization state. Mol Pharm 2007;4:323–38.
   PubMed Web of Science ®Google Scholar
• Tong W-QT, Whitesell G. In situ salt screening – a useful technique for discovery support and preformulation studies. Pharm Dev Technol 1998;3:215–23.
   PubMedGoogle Scholar
• Bowker MJ. A procedure for salt selection and optimization. In: Heinrich Stahl P, ed. Pharmaceutical salts: properties, selection, and use. 2nd revised edn. Weinheim, Germany: Wiley, John & Sons; 2011.
   Google Scholar
• Chowhan ZT. pH–solubility profiles or organic carboxylic acids and their salts. J Pharm Sci 1978;67:1257–60.
   PubMed Web of Science ®Google Scholar
• Serajuddin AT, Rosoff M. pH–Solubility profile of papaverine hydrochloride and its relationship to the dissolution rate of sustained-release pellets. J Pharm Sci 1984;73:1203–8.
   PubMed Web of Science ®Google Scholar
• Shah JC, Maniar M. pH-Dependent solubility and dissolution of bupivacaine and its relevance to the formulation of a controlled release system. J Control Release 1993;23:261–70.
   Web of Science ®Google Scholar
• Pudipeddi M, Serajuddin ATM, Grant DJW, Heinrich Stahl P. Solubility and dissolution of weak acids, bases, and salts. In: Heinrich Stahl P, ed. Pharmaceutical salts: properties, selection, and use. 2nd revised edn. Weinheim, Germany: Wiley, John & Sons; 2011.
   Google Scholar
• Benet LZ, Goyan JE. Potentiometric determination of dissociation constants. J Pharm Sci 1967;56:665–80.
   PubMed Web of Science ®Google Scholar
• Albert A, Serjeant EP. The ionization constants of typical acids and bases. The determination of ionization constants: a laboratory manual. Dordrecht: Springer Netherlands; 1984:136–175.
   Google Scholar
• Blake MI, Nona DA. Determination of ephedrine salts in liquid dosage forms. J Pharm Sci 1963;52:945–8.
   PubMed Web of Science ®Google Scholar
• Araujo GLBd, Zeller M, Smith D, et al. Unexpected single crystal growth induced by a wire and new crystalline structures of lapatinib. Cryst Growth Des 2016;16:6122–30.
   Web of Science ®Google Scholar
• Gould PL. Salt selection for basic drugs. Int J Pharm 1986;33:201–17.
   Web of Science ®Google Scholar
• Bastin RJ, Bowker MJ, Slater BJ. Salt selection and optimisation procedures for pharmaceutical new chemical entities. Org Process Res Dev 2000;4:427–35.
   Web of Science ®Google Scholar
• Abu TMS and Madhu P. Salt-selection strategies. In: Heinrich Stahl P, ed. Pharmaceutical salts: properties, selection, and use. 2nd revised edn. Weinheim, Germany: Wiley, John & Sons; 2011.
   Google Scholar
• Nie H, Su Y, Zhang M, et al. Solid-state spectroscopic investigation of molecular interactions between clofazimine and hypromellose phthalate in amorphous solid dispersions. Mol Pharm 2016;13:3964–75.
   PubMed Web of Science ®Google Scholar
• Song Y, Yang X, Chen X, et al. Investigation of drug–excipient interactions in lapatinib amorphous solid dispersions using solid-state NMR spectroscopy. Mol Pharm 2015;12:857–66.
   PubMed Web of Science ®Google Scholar
• Song Y, Zemlyanov D, Chen X, et al. Acid–base interactions of polystyrene sulfonic acid in amorphous solid dispersions using a combined UV/FTIR/XPS/ssNMR study. Mol Pharm 2016;13:483–92.
   PubMed Web of Science ®Google Scholar
• Song Y, Zemlyanov D, Chen X, et al. Acid–base interactions in amorphous solid dispersions of lumefantrine prepared by spray-drying and hot-melt extrusion using X-ray photoelectron spectroscopy. Int J Pharm 2016;514:456–64.
   PubMed Web of Science ®Google Scholar
• Telang C, Mujumdar S, Mathew M. Improved physical stability of amorphous state through acid–base interactions. J Pharm Sci 2009;98:2149–59.
   PubMed Web of Science ®Google Scholar
• Weuts I, Kempen D, Verreck G, et al. Salt formation in solid dispersions consisting of polyacrylic acid as a carrier and three basic model compounds resulting in very high glass transition temperatures and constant dissolution properties upon storage. Eur J Pharm Sci 2005;25:387–93.
   PubMed Web of Science ®Google Scholar
• Dittert LW, Higuchi T, Reese DR. Phase solubility technique in studying the formation of complex salts of triamterene. J Pharm Sci 1964;53:1325–8.
   PubMed Web of Science ®Google Scholar
• Zannou EA, Ji Q, Joshi YM, Serajuddin AT. Stabilization of the maleate salt of a basic drug by adjustment of microenvironmental pH in solid dosage form. Int J Pharm 2007;337:210–18.
   PubMed Web of Science ®Google Scholar
• Bowker MJ, Stahl PH, Chapter 37 – Preparation of water-soluble compounds through salt formation. In: Wermuth CG, ed. The practice of medicinal chemistry. 3rd ed. New York: Academic Press; 2008:747–66.
   Google Scholar
• Serajuddin AT. Salt formation to improve drug solubility. Adv Drug Deliv Rev 2007;59:603–16.
   PubMed Web of Science ®Google Scholar
• Christensen NPA, Rantanen J, Cornett C, Taylor LS. Disproportionation of the calcium salt of atorvastatin in the presence of acidic excipients. Eur J Pharm Biopharm 2012;82:410–16.
   PubMed Web of Science ®Google Scholar
• Kramer SF, Flynn GL. Solubility of organic hydrochlorides. J Pharm Sci 1972;61:1896–904.
   PubMed Web of Science ®Google Scholar
• Bogardus JB, Blackwood Jr RK. Solubility of doxycycline in aqueous solution. J Pharm Sci 1979;68:188–94.
   PubMed Web of Science ®Google Scholar
• Li S, Doyle P, Metz S, et al. Effect of chloride ion on dissolution of different salt forms of haloperidol, a model basic drug. J Pharm Sci 2005;94:2224–31.
   PubMed Web of Science ®Google Scholar
• Streng WH, Hsi SK, Helms PE, Tan HGH. General treatment of pH–solubility profiles of weak acids and bases and the effects of different acids on the solubility of a weak base. J Pharm Sci 1984;73:1679–84.
   PubMed Web of Science ®Google Scholar
• Lin SL, Lachman L, Swartz CJ, Huebner CF. Preformulation investigation. I. Relation of salt forms and biological activity of an experimental antihypertensive. J Pharm Sci 1972;61:1418–22.
   PubMed Web of Science ®Google Scholar
• Serajuddin ATM, Jarowski CI. Effect of diffusion layer pH and solubility on the dissolution rate of pharmaceutical bases and their hydrochloride salts I: phenazopyridine. J Pharm Sci 1985;74:142–7.
   PubMed Web of Science ®Google Scholar
• Li S, Wong S, Sethia S, et al. Investigation of solubility and dissolution of a free base and two different salt forms as a function of pH. Pharm Res 2005;22:628–35.
   PubMed Web of Science ®Google Scholar
• Black SN, Collier EA, Davey RJ, Roberts RJ. Structure, solubility, screening, and synthesis of molecular salts. J Pharm Sci 2007;96:1053–68.
   PubMed Web of Science ®Google Scholar
• Anderson BD, Conradi RA. Predictive relationships in the water solubility of salts of a nonsteroidal anti-inflammatory drug. J Pharm Sci 1985;74:815–20.
   PubMed Web of Science ®Google Scholar
• Rubino JT, Thomas E. Influence of solvent composition on the solubilities and solid-state properties of the sodium salts of some drugs. Int J Pharm 1990;65:141–5.
   Web of Science ®Google Scholar
• Serajuddin ATM, Jarowski CI. Effect of diffusion layer pH and solubility on the dissolution rate of pharmaceutical acids and their sodium salts II: salicylic acid, theophylline, and benzoic acid. J Pharm Sci 1985;74:148–54.
   PubMed Web of Science ®Google Scholar
• Serajuddin AT, Sheen PC, Mufson D, et al. Preformulation study of a poorly water-soluble drug, alpha-pentyl-3-(2-quinolinylmethoxy)benzenemethanol: selection of the base for dosage form design. J Pharm Sci 1986;75:492–6.
   PubMed Web of Science ®Google Scholar
• Ledwidge MT, Corrigan OI. Effects of surface active characteristics and solid state forms on the pH solubility profiles of drug–salt systems. Int J Pharm 1998;174:187–200.
   Web of Science ®Google Scholar
• Guerrieri P, Taylor L. Role of salt and excipient properties on disproportionation in the solid-state. Pharm Res 2009;26:2015–26.
   PubMed Web of Science ®Google Scholar
• Skrdla PJ, Zhang D. Disproportionation of a crystalline citrate salt of a developmental pharmaceutical compound: characterization of the kinetics using pH monitoring and online Raman spectroscopy plus quantitation of the crystalline free base form in binary physical mixtures using FT-Raman, XRPD and DSC. J Pharm Biomed Anal 2014;90:186–91.
   PubMed Web of Science ®Google Scholar
• Stephenson GA, Aburub A, Woods TA. Physical stability of salts of weak bases in the solid-state. J Pharm Sci 2011;100:1607–17.
   PubMed Web of Science ®Google Scholar
• Rohrs B, Thamann T, Gao P, et al. Tablet dissolution affected by a moisture mediated solid-state interaction between drug and disintegrant. Pharm Res 1999;16:1850–6.
   PubMed Web of Science ®Google Scholar
• Mathias NR, Xu Y, Patel D, et al. Assessing the risk of pH-dependent absorption for new molecular entities: a novel in vitro dissolution test, physicochemical analysis, and risk assessment strategy. Mol Pharm 2013;10:4063–73.
   PubMed Web of Science ®Google Scholar
• Guerrieri P, Jarring K, Taylor LS. Impact of counterion on the chemical stability of crystalline salts of procaine. J Pharm Sci 2010;99:3719–30.
   PubMed Web of Science ®Google Scholar
• Hsieh Y-L, Merritt JM, Yu W, Taylor LS. Salt stability – the effect of pHmax on salt to free base conversion. Pharm Res 2015;32:3110–18.
   PubMed Web of Science ®Google Scholar
• Maurin MB, Addicks WJ, Rowe SM, Hogan R. Physical chemical properties of alpha styryl carbinol antifungal agents. Pharm Res 1993;10:309–12.
   PubMed Web of Science ®Google Scholar
• Hsieh Y-L, Taylor LS. Salt stability – effect of particle size, relative humidity, temperature and composition on salt to free base conversion. Pharm Res 2015;32:549–61.
   PubMed Web of Science ®Google Scholar
• Hall NF, Sprinkle MR. Relations between the structure and strength of certain organic bases in aqueous solution. J Am Chem Soc 1932;54:3469–85.
   Google Scholar
• Perrin D. The effect of temperature on pK values of organic bases. Aust J Chem 1964;17:484–8.
   Web of Science ®Google Scholar
• Perrin DD. Dissociation constants of organic bases in aqueous solution. London: Butterworths; 1965.
   Google Scholar
• Salazar MR, Thompson SL, E. Laintz K, et al. Degradation of a poly(ester urethane) elastomer. IV. Sorption and diffusion of water in PBX 9501 and its components. J Appl Polym Sci 2007;105:1063–76.
   Web of Science ®Google Scholar
• Guerrieri P, Salameh AK, Taylor LS. Effect of small levels of impurities on the water vapor sorption behavior of ranitidine HCl. Pharm Res 2007;24:147–56.
   PubMed Web of Science ®Google Scholar
• Kwok K, Mauer LJ, Taylor LS. Kinetics of moisture-induced hydrolysis in powder blends stored at and below the deliquescence relative humidity: investigation of sucrose–citric acid mixtures . J Agri Food Chem 2010;58:11716–24.
   PubMed Web of Science ®Google Scholar
• Nie H, Dave RH. To differentiate end-point of wet granulation for various grades of hydroxypropyl methylcellulose by utilizing thermal and rheological approaches. J Pharm Sci Pharmacol 2015;2:177–93.
   Google Scholar
• Williams AC, Cooper VB, Thomas L, et al. Evaluation of drug physical form during granulation, tabletting and storage. Int J Pharm 2004;275:29–39.
   PubMed Web of Science ®Google Scholar
• Nie H, Xu W, Taylor LS, et al. Crystalline solid dispersion-a strategy to slowdown salt disproportionation in solid state formulations during storage and wet granulation. Int J Pharm 2017;517:203–15.
   PubMed Web of Science ®Google Scholar
• Unger EF. Weighing benefits and risks-the FDA's review of prasugrel. N Engl J Med 2009;361:942–5.
   PubMed Web of Science ®Google Scholar
• de Oliveira APM, Cunha TA, Serpa RC, et al. Improvement of enalapril maleate chemical stability by high shear melting granulation. Pharm Dev Technol 2015;20:1002–8.
   PubMed Web of Science ®Google Scholar
• Shiromani PK, Bavitz JF. Effect of moisture on the physical and chemical stability of granulations and tablets of the angiotensin converting enzyme inhibitor, enalapril maleate. Drug Dev Ind Pharm 1986;12:2467–80.
   Web of Science ®Google Scholar
• Al-Omari MM, Abdelah MK, Badwan AA, Jaber AM. Effect of the drug-matrix on the stability of enalapril maleate in tablet formulations. J Pharm Biomed Anal 2001;25:893–902.
   PubMed Web of Science ®Google Scholar
• Taylor LS, Langkilde FW. Evaluation of solid-state forms present in tablets by Raman spectroscopy. J Pharm Sci 2000;89:1342–53.
   PubMed Web of Science ®Google Scholar
• Guerrieri P, Rumondor ACF, Li T, Taylor LS. Analysis of relationships between solid-state properties, counterion, and developability of pharmaceutical salts. AAPS PharmSciTech 2010;11:1212–22.
   PubMed Web of Science ®Google Scholar
• Morris KR, Fakes MG, Thakur AB, et al. An integrated approach to the selection of optimal salt form for a new drug candidate. Int J Pharm 1994;105:209–17.
   Web of Science ®Google Scholar
• Danielle Giron DJWG, Evaluation of solid-state properties of salts. In: Heinrich Stahl P, ed. Pharmaceutical salts: properties, selection, and use. 2nd revised edn. Weinheim, Germany: Wiley, John & Sons; 2011.
   Google Scholar
• Van Campen L, Amidon GL, Zografi G. Moisture sorption kinetics for water-soluble substances. II: experimental verification of heat transport control. J Pharm Sci 1983;72:1388–93.
   PubMed Web of Science ®Google Scholar
• Van Campen L, Amidon GL, Zografi G. Moisture sorption kinetics for water-soluble substances. III: theoretical and experimental studies in air. J Pharm Sci 1983;72:1394–8.
   PubMed Web of Science ®Google Scholar
• van Campen L, Amidon GL, Zografi G. Moisture sorption kinetics for water-soluble substances I: Theoretical considerations of heat transport control. J Pharm Sci 1983;72:1381–8.
   PubMed Web of Science ®Google Scholar
• Scheef C-A, Oelkrug D, Schmidt PC. Surface acidity of solid pharmaceutical excipients III. Excipients for solid dosage forms. Eur J Pharm Biopharm 1998;46:209–13.
   PubMed Web of Science ®Google Scholar
• Govindarajan R, Zinchuk A, Hancock B, et al. Ionization states in the microenvironment of solid dosage forms: effect of formulation variables and processing. Pharm Res 2006;23:2454–68.
   PubMed Web of Science ®Google Scholar
• Pudipeddi M, Zannou EA, Vasanthavada M, et al. Measurement of surface pH of pharmaceutical solids: a critical evaluation of indicator dye-sorption method and its comparison with slurry pH method. J Pharm Sci 2008;97:1831–42.
   PubMed Web of Science ®Google Scholar
• Serajuddin ATM, Thakur AB, Ghoshal RN, et al. Selection of solid dosage form composition through drug–excipient compatibility testing. J Pharm Sci 1999;88:696–704.
   PubMed Web of Science ®Google Scholar
• Merritt J, Viswanath S, Stephenson G. Implementing quality by design in pharmaceutical salt selection: a modeling approach to understanding disproportionation. Pharm Res 2013;30:203–17.
   PubMed Web of Science ®Google Scholar
• John C, Xu W, Lupton L, Harmon P. Formulating weakly basic HCl salts: relative ability of common excipients to induce disproportionation and the unique deleterious effects of magnesium stearate. Pharm Res 2013;30:1628–41.
   PubMed Web of Science ®Google Scholar
• Kararli T, Needham T, Seul C, Finnegan P. Solid-state interaction of magnesium oxide and ibuprofen to form a salt. Pharm Res 1989;6:804–8.
   PubMed Web of Science ®Google Scholar
• Powney J, Addison CC. Part VI – the surface activity and critical concentrations of aqueous solutions of saturated soaps under conditions of suppressed hydrolysis. Trans Faraday Soc 1938;34:372–7.
   Google Scholar
• Vold MJ, Hattiangdi GS, Vold RD. Crystal forms of anhydrous calcium stearate derivable from calcium stearate monohydrate. J Colloid Sci 1949;4:93–101.
   PubMedGoogle Scholar
• Borgwardt RH, Bruce KR. Effect of specific surface area on the reactivity of CaO with SO2. AIChE J 1986;32:239–46.
   Web of Science ®Google Scholar
• Laine NR, Vastola FJ, Walker PL. The importance of active surface area in the carbon-oxygen reaction1,2. J Phys Chem 1963;67:2030–4.
   Web of Science ®Google Scholar
• Walker Jr PL, Rusinko Jr F, Austin LG. Gas reactions of carbon. In: Eley DD, Paul BW, eds. Advances in catalysis. Vol. 11. Academic Press; 1959:133–221.
   Google Scholar
• Oxtoby DW, Gillis HP, Campion A. Principles of modern chemistry. Belmont, California, USA: Brooks/Cole Cengage Learning; 2012.
   Google Scholar
• Greenspan L. Humidity fixed points of binary saturated aqueous solutions. J Res Natl Bur Stand 1977;81A:81–9.
   Google Scholar
• Yang L, Pabalan RT, Juckett MR. Deliquescence relative humidity measurements using an electrical conductivity method. J Solution Chem 2006;35:583–604.
   Web of Science ®Google Scholar
• Yang L, Juckett MR, Pabalan RT. Conductivity behavior of salt deposits on the surface of engineered barrier materials for the potential high-level nuclear waste repository at Yucca Mountain, Nevada. MRS Online Proc Library Arch 2004;824:CC1.4 (7 pages).
   Google Scholar
• Tang IN, Munkelwitz HR, Davis JG. Aerosol growth studies — IV. Phase transformation of mixed salt aerosols in a moist atmosphere. J Aerosol Sci 1978;9:505–11.
   Google Scholar
• Gordon KC, McGoverin CM. Raman mapping of pharmaceuticals. Int J Pharm 2011;417:151–62.
   PubMed Web of Science ®Google Scholar
• Hausman DS, Cambron RT, Sakr A. Application of Raman spectroscopy for on-line monitoring of low dose blend uniformity. Int J Pharm 2005;298:80–90.
   PubMed Web of Science ®Google Scholar
• Henson MJ, Zhang L. Drug characterization in low dosage pharmaceutical tablets using raman microscopic mapping. Appl Spectrosc 2006;60:1247–55.
   PubMed Web of Science ®Google Scholar
• Ward S, Perkins M, Zhang J, et al. Identifying and mapping surface amorphous domains. Pharm Res 2005;22:1195–202.
   PubMed Web of Science ®Google Scholar
• Widjaja E, Kanaujia P, Lau G, et al. Detection of trace crystallinity in an amorphous system using Raman microscopy and chemometric analysis. Eur J Pharm Sci 2011;42:45–54.
   PubMed Web of Science ®Google Scholar
• Ozaki Y, Šašić S. Introduction to Raman spectroscopy. Pharmaceutical applications of Raman spectroscopy. New Jersey, USA: John Wiley & Sons, Inc.; 2007:1–28.
   Google Scholar
• John CT, Harmon PA. Pharmaceutical compositions that inhibit disproportionation. Google Patents 2014.
   Google Scholar