The freezing step in lyophilization: Physico-chemical fundamentals, freezing methods and consequences on process performance and quality attributes of biopharmaceuticals

European Journal of Pharmaceutics and Biopharmaceutics

Volumn 78, Issue 2, 2011, Pages 248-263

  Kasper, Julia Christina ^a   Friess, Wolfgang ^a  

^a UNIVERSITY OF MUNICH   (Germany)

Author keywords

Freeze drying; Influence on process performance; Influence on product quality; Influence on protein stability; Lyophilization; Modifications of the freezing step

Indexed keywords

COOLING; CRYSTALLIZATION; DRUG QUALITY; FREEZE DRYING; FREEZING; MOISTURE; PHYSICAL CHEMISTRY; PROCESS OPTIMIZATION; PROTEIN STABILITY; REVIEW; SAMPLING; SEPARATION TECHNIQUE; TEMPERATURE; ULTRASOUND; VITRIFICATION;

BIOPHARMACEUTICS; FREEZE DRYING; FREEZING;

EID: 79955874261     PISSN: 09396411     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.ejpb.2011.03.010     Document Type: Review

References (117)

1. X. Tang, M. Pikal, Design of freeze-drying processes for pharmaceuticals: practical advice, Pharm. Res. 21 (2004) 191-200.
2. H.R. Constantino, Excipients of use in lyophilized pharmaceutical peptide, protein, and other bioproducts, in: H.R. Constantino (Ed.), Lyophilization of Biopharmaceuticals, AAPS Press, Arlington, VA, USA, 2004.
3. J.F. Carpenter, M.J. Pikal, B.S. Chang, T.W. Randolph, Rational design of stable lyophilized protein formulations: some practical advice, Pharm. Res. 14 (1997) 969-975.
4. F. Franks, Freeze-drying of bioproducts: putting principles into practice, Eur. J. Pharm. Biopharm. 45 (1998) 221-229. (Pubitemid 28270810)
5. J. Liu, T. Viverette, M. Virgin, M. Anderson, P. Dalal, A study of the impact of freezing on the lyophilization of a concentrated formulation with a high fill depth, Pharm. Dev. Technol. 10 (2005) 261-272. (Pubitemid 40677446)
6. M.J. Pikal, S. Rambhatla, R. Ramot, The impact of the freezing stage in lyophilization: effects of the ice nucleation temperature on process design and product quality, Am. Pharm. Rev. 5 (2002) 48-53.
7. P. Cameron, Good Pharmaceutical Freeze-Drying Practice, Interpharm Press, Inc., Buffalo Grove, USA, 1997.
8. G.-W. Oetjen, P. Haseley, Freeze-Drying, Wiley-VHC Verlag, Weinheim, 2004.
9. T.W. Patapoff, D.E. Overcashier, The importance of freezing on lyophilization cycle development, Biopharm 15 (2002) 16-21.
10. T. Jennings, The Freezing Process, in: Lyophilization, Introduction and Basic Principles, Interpharm Press, Englewood, USA, 1999.
11. F. Franks, T. Auffret, Freeze-Drying of Pharmaceuticals and Biopharmaceuticals, RSC Publishing, Cambridge, UK, 2007.
12. J.A. Searles, Freezing and annealing phenomena in lyophilization, in: L. Rey, J.C. May (Eds.), Freeze-Drying/Lyophilization of Pharmaceutical and Biological Products, Marcel Dekker, Inc., USA, New York, 2004.
13. A. Hottot, S. Vessot, J. Andrieu, Freeze drying of pharmaceuticals in vials: influence of freezing protocol and sample configuration on ice morphology and freeze-dried cake texture, Chem. Eng. Process. 46 (2007) 666-674. (Pubitemid 46454463)
14. J.A. Searles, J.F. Carpenter, T.W. Randolph, The ice nucleation temperature determines the primary drying rate of lyophilization for samples frozen on a temperature-controlled shelf, J. Pharm. Sci. 90 (2001) 860-871.
15. G. Petzold, J. Aguilera, Ice morphology: fundamentals and technological applications in foods, Food Biophys. 4 (2009) 378-396.
16. B.S. Bhatnagar, R.H. Bogner, M.J. Pikal, Protein stability during freezing: separation of stresses and mechanisms of protein stabilization, Pharm. Dev. Technol. 12 (2007) 505-523. (Pubitemid 350041532)
17. J.J. Schwegman, F.C. John, L.N. Steven, Evidence of partial unfolding of proteins at the ice/freeze-concentrate interface by infrared microscopy, J. Pharm. Sci. 98 (2009) 3239-3246.
18. J. Liu, Physical characterization of pharmaceutical formulations in frozen and freeze-dried solid states: techniques and applications in freeze-drying development, Pharm. Dev. Technol. 11 (2006) 3-28.
19. S.L. Nail, S. Jiang, S. Chongprasert, S.A. Knopp, Fundamentals of freeze-drying, in: S.L. Nail, M.J. Akers (Eds.), Development and Manufacture of Protein Pharmaceuticals, Kluwer Academic/Plenum Publisher, New York, 2002.
20. S. Rambhatla, R. Ramot, C. Bhugra, M. Pikal, Heat and mass transfer scale-up issues during freeze drying: II. Control and characterization of the degree of supercooling, AAPS PharmSciTech 5 (2004) 54-62.
21. M. Akyurt, G. Zaki, B. Habeebullah, Freezing phenomena in ice-water systems, Energy Convers. Manage. 43 (2002) 1773-1789.
22. M. Matsumoto, S. Saito, I. Ohmine, Molecular dynamics simulation of the ice nucleation and growth process leading to water freezing, Nature 416 (2002) 409-413. (Pubitemid 34272871)
23. T. Jennings, The importance of process water, in: Lyophilization, Introduction and Basic Principles, Interpharm Press, Englewood, USA, 1999.
24. P.W. Wilson, A.F. Heneghan, A.D.J. Haymet, Ice nucleation in nature: supercooling point (SCP) measurements and the role of heterogeneous nucleation, Cryobiology 46 (2003) 88-98. (Pubitemid 36268986)
25. G. Blond, Velocity of linear crystallization of ice in macromolecular systems, Cryobiology 25 (1988) 61-66. (Pubitemid 18039793)
26. M.J. Pikal, S. Shah, D. Senior, J.E. Lang, Physical chemistry of freeze-drying: measurement of sublimation rates for frozen aqueous solutions by a microbalance technique, J. Pharm. Sci. 72 (1983) 635-650.
27. R.H.M. Hatley, A. Mant, Determination of the unfrozen water content of maximally freeze-concentrated carbohydrate solutions, Int. J. Biol. Macromol. 15 (1993) 227-232. (Pubitemid 23226615)
28. G.H.J.A. Tammanm, The States of Aggregation: The Changes in the State of Matter in their Dependence upon Pressure and Temperature, Van Nostrand Company, Inc., New York, 1925.
29. V. Kett, D. McMahon, K. Ward, Thermoanalytical techniques for the investigation of the freeze drying process and freeze-dried products, Curr. Pharm. Biotechnol. 6 (2005) 239-250. (Pubitemid 40933059)
30. A.P. MacKenzie, Non-equilibrium freezing behaviour of aqueous systems, Philos. Trans. Roy. Soc. London, Ser. B 278 (1977) 167-189.
31. Y. Roos, M. Karel, Phase transitions of amorphous sucrose and frozen sucrose solutions, J. Food Sci. 56 (1991) 266-267.
32. T.W. Randolph, Phase separation of excipients during lyophilization: effects on protein stability, J. Pharm. Sci. 86 (1997) 1198-1203.
33. M.C. Heller, J.F. Carpenter, T.W. Randolph, Effects of phase separating systems on lyophilized hemoglobin, J. Pharm. Sci. 85 (1996) 1358-1362.
34. M.C. Heller, J.F. Carpenter, T.W. Randolph, Manipulation of lyophilizationinduced phase separation: implications for pharmaceutical proteins, Biotechnol. Prog. 13 (1997) 590-596.
35. B.Y. Zaslavsky, T.O. Bagirov, A.A. Borovskaya, N.D. Gulaeva, L.H. Miheeva, A.U. Mahmudov, M.N. Rodnikova, Structure of water as a key factor of phase separation in aqueous mixtures of two nonionic polymers, Polymer 30 (1989) 2104-2111. (Pubitemid 20599590)
36. A. Pyne, K. Chatterjee, R. Suryanarayanan, Crystalline to amorphous transition of disodium hydrogen phosphate during primary drying, Pharm. Res. 20 (2003) 802-803.
37. T.W. Randolph, J.A. Searles, Freezing and annealing phenomena in lyophilization: effects upon primary drying rate, morphology, and heterogeneity, Am. Pharm. Rev. 5 (2002) 40-47.
38. T. Cochran, S.L. Nail, Ice nucleation temperature influences recovery of activity of a model protein after freeze drying, J. Pharm. Sci. 98 (2009) 3495-3498.
39. M.C. Heller, J.F. Carpenter, T.W. Randolph, Protein formulation and lyophilization cycle design: prevention of damage due to freezeconcentration induced phase separation, Biotechnol. Bioeng. 63 (1999) 166-174.
40. S. Jiang, S.L. Nail, Effect of process conditions on recovery of protein activity after freezing and freeze-drying, Eur. J. Pharm. Biopharm. 45 (1998) 249-257. (Pubitemid 28270813)
41. J.A. Searles, J.F. Carpenter, T.W. Randolph, Annealing to optimize the primary drying rate, reduce freezing-induced drying rate heterogeneity, and determine Tg′ in pharmaceutical lyophilization, J. Pharm. Sci. 90 (2001) 872-887. (Pubitemid 32645945)
42. X. Lu, M.J. Pikal, Freeze-drying of mannitol - trehalose - sodium chloride-based formulations: the impact of annealing on dry layer resistance to mass transfer and cake structure, Pharm. Dev. Technol. 9 (2004) 85-95. (Pubitemid 38250229)
43. H. Schoof, J. Apel, I. Heschel, G. Rau, Control of pore structure and size in freeze-dried collagen sponges, J. Biomed. Mater. Res. 58 (2001) 352-357. (Pubitemid 32643182)
44. T.D. Rowe, A technique for the nucleation of ice, in: International Symposium on Biological Product Freeze-Drying and Formulation, 1990.
45. S. Patel, C. Bhugra, M. Pikal, Reduced pressure ice fog technique for controlled ice nucleation during freeze-drying, AAPS PharmSciTech 10 (2009) 1406-1411.
46. A. Petersen, H. Schneider, G. Rau, B. Glasmacher, A new approach for freezing of aqueous solutions under active control of the nucleation temperature, Cryobiology 53 (2006) 248-257. (Pubitemid 44353456)
47. A. Petersen, G. Rau, B. Glasmacher, Reduction of primary freeze-drying time by electric field induced ice nucleus formation, Heat Mass Transfer 42 (2006) 929-938. (Pubitemid 43999846)
48. W. Rau, Eiskeimbildung durch Dielektrische Polarisation, Z. Naturforsch. 6 (1951) 649-657.
49. T. Hozumi, A. Saito, S. Okawa, K. Watanabe, Effects of electrode materials on freezing of supercooled water in electric freeze control, Int. J. Refrig. 26 (2003) 537-542.
50. T. Inada, X. Zhang, A. Yabe, Y. Kozawa, Active control of phase change from supercooled water to ice by ultrasonic vibration 1. Control of freezing temperature, Int. J. Heat Mass Transfer 44 (2001) 4523-4531.
51. X. Zhang, T. Inada, A. Yabe, S. Lu, Y. Kozawa, Active control of phase change from supercooled water to ice by ultrasonic vibration 2. Generation of ice slurries and effect of bubble nuclei, Int. J. Heat Mass Transfer 44 (2001) 4533-4539.
52. X. Zhang, T. Inada, A. Tezuka, Ultrasonic-induced nucleation of ice in water containing air bubbles, Ultrason. Sonochem. 10 (2003) 71-76.
53. M. Saclier, R. Peczalski, J. Andrieu, A theoretical model for ice primary nucleation induced by acoustic cavitation, Ultrason. Sonochem. 17 (2010) 98-105.
54. K. Nakagawa, A. Hottot, S. Vessot, J. Andrieu, Influence of controlled nucleation by ultrasounds on ice morphology of frozen formulations for pharmaceutical proteins freeze-drying, Chem. Eng. Process. 45 (2006) 783-791. (Pubitemid 44250811)
55. A. Hottot, K. Nakagawa, J. Andrieu, Effect of ultrasound-controlled nucleation on structural and morphological properties of freeze-dried mannitol solutions, Chem. Eng. Res. Des. 86 (2008) 193-200. (Pubitemid 351722807)
56. M. Saclier, R. Peczalski, J. Andrieu, Effect of ultrasonically induced nucleation on ice crystals' size and shape during freezing in vials, Chem. Eng. Sci. 65 (2010) 3064-3071.
57. S. Passot, I.C. Trelea, M. Marin, M. Galan, G.J. Morris, F. Fonseca, Effect of controlled ice nucleation on primary drying stage and protein recovery in vials cooled in a modified freeze-dryer, J. Biomech. Eng. 131 (2009) 074511-074515.
58. K. McDonald, D.-W. Sun, Vacuum cooling technology for the food processing industry: a review, J. Food Eng. 45 (2000) 55-65.
59. M. Kramer, B. Sennhenn, G. Lee, Freeze-drying using vacuum-induced surface freezing, J. Pharm. Sci. 91 (2002) 433-443.
60. P.D. Sanz, L. Otero, C. de Elvira, J.A. Carrasco, Freezing processes in highpressure domains, Int. J. Refrig. 20 (1997) 301-307.
61. B. Li, D.-W. Sun, Novel methods for rapid freezing and thawing of foods - a review, J. Food Eng. 54 (2002) 175-182. (Pubitemid 34624125)
62. M.N. Martino, L. Otero, P.D. Sanz, N.E. Zaritzky, Size and location of ice crystals in pork frozen by high-pressure-assisted freezing as compared to classical methods, Meat Sci. 50 (1998) 303-313. (Pubitemid 128180403)
63. L. Otero, P.D. Sanz, High-pressure shift freezing. Part 1. Amount of ice instantaneously formed in the process, Biotechnol. Prog. 16 (2000) 1030-1036. (Pubitemid 32044856)
64. P.P. Fernández, L. Otero, B. Guignon, P.D. Sanz, High-pressure shift freezing versus high-pressure assisted freezing: effects on the microstructure of a food model, Food Hydrocolloids 20 (2006) 510-522. (Pubitemid 43213134)
65. T.H. Gasteyer, R.R. Sever, B. Hunek, N. Grinter, M.L. Verdone, Lyophilization system and method, in: Patent Application Publication, United States, 2007.
66. B.M. Rampersad, R.R. Sever, B. Hunek, T.H. Gasteyer, Freeze-dryer and method of controlling the same, in: Patent Application Publication, United States, 2010.
67. R. Bursac, R. Sever, B. Hunek, A practical method for resolving the nucleation problem in lyophilization, Bioprocess Int. (2009) 66-72.
68. 〈http://www.spscientific.com/ControLyoTechnology〉 (accessed 12.02.10).
69. N. Cochet, P. Widehem, Ice crystallization by Pseudomonas syringae, Appl. Microbiol. Biotechnol. 54 (2000) 153-161. (Pubitemid 30662722)
70. B. Vonnegut, The nucleation of ice formation by silver iodide, J. Appl. Chem. 18 (1947) 593-595.
71. M. Gavish, J. Wang, M. Eisenstein, M. Lahav, L. Leiserowitz, The role of crystal polarity in alpha-amino acid crystals for induced nucleation of ice, Science 256 (1992) 815-818.
72. K.-i. Izutsu, S. Kojima, Freeze-concentration separates proteins and polymer excipients into different amorphous phases, Pharm. Res. 17 (2000) 1316-1322.
73. L.R. Maki, E.L. Galyan, M.-M. Chang-Chien, D.R. Caldwell, Ice nucleation induced by Pseudomonas syringae, Appl. Environ. Microbiol. 28 (1974) 456-459.
74. D.L. Teagarden, D.S. Baker, Practical aspects of lyophilization using nonaqueous co-solvent systems, Eur. J. Pharm. Sci. 15 (2002) 115-133.
75. K. Kasraian, P.P. DeLuca, Thermal analysis of the tertiary butyl alcoholwater system and its implications on freeze-drying, Pharm. Res. 12 (1995) 484-490.
76. S. Wittaya-Areekul, S.L. Nail, Freeze-drying of tert-butyl alcohol/water cosolvent systems: effects of formulation and process variables on residual solvents, J. Pharm. Sci. 87 (1998) 491-495.
77. K. Kasraian, P.P. DeLuca, The effect of tertiary butyl alcohol on the resistance of the dry product layer during primary drying, Pharm. Res. 12 (1995) 491-495.
78. S. Wittaya-Areekul, G.F. Needham, N. Milton, M.L. Roy, S.L. Nail, Freeze-drying of tert-butanol/water cosolvent systems: a case report on formation of a friable freeze-dried powder of tobramycin sulfate, J. Pharm. Sci. 91 (2002) 1147-1155.
79. S.D. Webb, J.L. Cleland, J.F. Carpenter, T.W. Randolph, Effects of annealing lyophilized and spray-lyophilized formulations of recombinant human interferon-γ, J. Pharm. Sci. 92 (2003) 715-729.
80. S.D. Webb, J.L. Cleland, J.F. Carpenter, T.W. Randolph, Effects of annealing lyophilized and spray-lyophilized formulations of recombinant human interferon-γ, J. Pharm. Sci. 92 (2003) 715-729.
81. M.J. Pikal, M.L. Roy, S. Shah, Mass and heat transfer in vial freeze-drying of pharmaceuticals: role of the vial, J. Pharm. Sci. 73 (1984) 1224-1237.
82. J. Oesterle, F. Franks, T. Auffret, The influence of tertiary butyl alcohol and volatile salts on the sublimation of ice from frozen sucrose solutions: implications for freeze-drying, Pharm. Dev. Technol. 3 (1998) 175-183. (Pubitemid 28310932)
83. R. Daoussi, S. Vessot, J. Andrieu, O. Monnier, Sublimation kinetics and sublimation end-point times during freeze-drying of pharmaceutical active principle with organic co-solvent formulations, Chem. Eng. Res. Des. 87 (2009) 899-907.
84. R.K. Cavatur, N.M. Vemuri, A. Pyne, Z. Chrzan, D. Toledo-Velasquez, R. Suryanarayanan, Crystallization behavior of mannitol in frozen aqueous solutions, Pharm. Res. 19 (2002) 894-900.
85. A. Pyne, K. Chatterjee, R. Suryanarayanan, Solute crystallization in mannitol - glycine systems - implications on protein stabilization in freeze-dried formulations, J. Pharm. Sci. 92 (2003) 2272-2283.
86. K. Izutsu, S. Yoshioka, T. Terao, Effect of mannitol crystallinity on the stabilization of enzymes during freeze-drying, Chem. Pharm. Bull. 42 (1994) 5-8. (Pubitemid 24067499)
87. A.J. Cannon, E.H. Trappler, The influence of lyophilization on the polymorphic behavior of mannitol, PDA J. Pharm. Sci. Technol. 54 (2000) 13-22. (Pubitemid 30183796)
88. A.I. Kim, M.J. Akers, S.L. Nail, The physical state of mannitol after freezedrying: effects of mannitol concentration, freezing rate, and a noncrystallizing cosolute, J. Pharm. Sci. 87 (1998) 931-935. (Pubitemid 28381249)
89. K. Nakagawa, W. Murakami, J. Andrieu, S. Vessot, Freezing step controls the mannitol phase composition heterogeneity, Chem. Eng. Res. Des. 87 (2009) 1017-1027.
90. X. Liao, R. Krishnamurthy, R. Suryanarayanan, Influence of processing conditions on the physical state of mannitol - implications in freeze-drying, Pharm. Res. 24 (2007) 370-376.
91. A. Hawe, W. Frieß, Impact of freezing procedure and annealing on the physico-chemical properties and the formation of mannitol hydrate in mannitol-sucrose - NaCl formulations, Eur. J. Pharm. Biopharm. 64 (2006) 316-325. (Pubitemid 44585207)
92. P. Hiwale, A. Amin, L. Kumar, A.K. Bansal, Variables affecting reconstitution time of dry powder for injection, Pharm. Technol. 2 (July) (2008).
93. S.J. Shire, Z. Shahrokh, J. Liu, Challenges in the development of high protein concentration formulations, J. Pharm. Sci. 93 (2004) 1390-1402.
94. W. Wang, Lyophilization and development of solid protein pharmaceuticals, Int. J. Pharm. 203 (2000) 1-60.
95. E.Y. Chi, S. Krishnan, T.W. Randolph, J.F. Carpenter, Physical stability of proteins in aqueous solution: mechanism and driving forces in nonnative protein aggregation, Pharm. Res. 20 (2003) 1325-1336.
96. K. Dill, Dominant forces in protein folding, Biochemistry 29 (1990) 7133-7155. (Pubitemid 20230041)
97. B.S. Bhatnagar, M.J. Pikal, R.H. Bogner, Study of the individual contributions of ice formation and freeze-concentration on isothermal stability of lactate dehydrogenase during freezing, J. Pharm. Sci. 97 (2008) 798-814.
98. X.C. Tang, M.J. Pikal, The effect of stabilizers and denaturants on the cold denaturation temperatures of proteins and implications for freeze-drying, Pharm. Res. 22 (2005) 1167-1175.
99. G. Gomez, M.J. Pikal, N. Rodriguez-Hornedo, Effect of initial buffer composition on pH changes during far-from-equilibrium freezing of sodium phosphate buffer solutions, Pharm. Res. 18 (2001) 90-97.
100. T.J. Anchordoquy, J.F. Carpenter, Polymers protect lactate dehydrogenase during freeze-drying by inhibiting dissociation in the frozen state, Arch. Biochem. Biophys. 332 (1996) 231-238. (Pubitemid 26260384)
101. D. Piedmonte, C. Summers, A. McAuley, L. Karamujic, G. Ratnaswamy, Sorbitol crystallization can lead to protein aggregation in frozen protein formulations, Pharm. Res. 24 (2007) 136-146.
102. E.J. Workman, S.E. Reynolds, Electrical phenomena occurring during the freezing of dilute aqueous solutions and their possible relationship to thunderstorm electricity, Phys. Rev. 78 (1950) 254.
103. W. Norde, Adsorption of proteins from solution at the solid-liquid interface, Adv. Colloid Interface Sci. 25 (1986) 267-340.
104. B.S. Chang, B.S. Kendrick, J.F. Carpenter, Surface-induced denaturation of proteins during freezing and its inhibition by surfactants, J. Pharm. Sci. 85 (1996) 1325-1330.
105. J.F. Carpenter, T. Arakawa, J.H. Crowe, Interactions of stabilizing additives with proteins during freeze-thawing and freeze-drying, Dev. Biol. 74 (1992) 225-238 (discussion 238-229).
106. M.J. Pikal, Mechanisms of protein stabilization during freeze-drying and storage: the relative importance of thermodynamic stabilization and glassy state relaxation dynamics, in: L. Rey, J.C. May (Eds.), In Freeze-Drying/ Lyophilization of Pharmaceutical and Biological Products, Marcel Dekker, Inc., New York, 2004, pp. 63-107.
107. G.B. Strambini, E. Gabellieri, Proteins in frozen solutions: evidence of ice-induced partial unfolding, Biophys. J. 70 (1996) 971-976. (Pubitemid 26028311)
108. J.-M. Sarciaux, S. Mansour, M.J. Hageman, S.L. Nail, Effects of buffer composition and processing conditions on aggregation of bovine IgG during freeze-drying, J. Pharm. Sci. 88 (1999) 1354-1361.
109. B.M. Eckhardt, J.Q. Oeswein, T.A. Bewley, Effect of freezing on aggregation of human growth hormone, Pharm. Res. 8 (1991) 1360-1364.
110. S. Nema, K.E. Avis, Freeze - thaw studies of a model protein, lactate dehydrogenase, in the presence of cryoprotectants, J. Parenter. Sci. Technol. 47 (1993) 76-83.
111. K. Izutsu, S. Yoshioka, T. Terao, Decreased protein-stabilizing effects of cryoprotectants due to crystallization, Pharm. Res. 10 (1993) 1232-1237.
112. D. Dixon, S. Tchessalov, A. Barry, N. Warne, The impact of protein concentration on mannitol and sodium chloride crystallinity and polymorphism upon lyophilization, J. Pharm. Sci. 98 (2009) 3419-3429.
113. B.S. Chang, C.S. Randall, Use of subambient thermal analysis to optimize protein lyophilization, Cryobiology 29 (1992) 632-656.
114. C.C. Hsu, H.M. Nguyen, D.A. Yeung, D.A. Brooks, G.S. Koe, T.A. Bewley, R. Pearlman, Surface denaturation at solid - void interface - a possible pathway by which opalescent participates form during the storage of lyophilized tissue-type plasminogen activator at high temperatures, Pharm. Res. 12 (1995) 69-77.
115. B.S. Chang, G. Reeder, J.F. Carpenter, Development of a stable freeze-dried formulation of recombinant human interleukin-1 receptor antagonist, Pharm. Res. 13 (1996) 243-249.
116. X.M. Lam, H.R. Costantino, D.E. Overcashier, T.H. Nguyen, C.C. Hsu, Replacing succinate with glycolate buffer improves the stability of lyophilized interferon-[gamma], Int. J. Pharm. 142 (1996) 85-95.
117. H.R. Costantino, K. Griebenow, R. Langer, A.M. Klibanov, On the pH memory of lyophilized compounds containing protein functional groups, Biotechnol. Bioeng. 53 (1997) 345-348.