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Nanoprecipitation versus emulsion-based techniques for the encapsulation of proteins into biodegradable nanoparticles and process-related stability issues

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Abstract

The goal of this study was to investigate the entrapment of 3 different model proteins (tetanus toxoid, lysozyme, and insulin) into poly(D,L-lactic acid) and poly(D,L-lactic-co-glycolic acid) nanoparticles and to address process-related stability issues. For that purpose, a modified nanoprecipitation method as well as 2 emulsion-based encapsulation techniques (ie, a solid-in oil-in water (s/o/w) and a double emulsion (w1/o/w2) method) were used. The main modification of nanoprecipitation involved the use of a wide range of miscible organic solvents such as dimethylsulfoxide and ethanol instead of the common acetone and water. The results obtained showed that tetanus toxoid and lysozyme were efficiently incorporated by the double emulsion procedure when ethyl acetate was used as solvent (>80% entrapment efficiency), whereas it was necessary to use methylene chloride to achieve high insulin entrapment efficiencies. The use of the s/o/w method or the formation of a more hydrophobic protein-surfactant ion pair did not improve protein loading. The nanoprecipitation method led to a homogenous population of small nanoparticles (with size ranging from ≈130 to 560 nm) and in some cases also improved experimental drug loadings, especially for lysozyme (entrapment efficiency >90%). With respect to drug content determination, a simple and quick matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method provided results very close to those obtained by reverse phase-high-performance liquid chromatography. With respect to protein stability, the duration and intensity of sonication were not a concern for tetanus toxoid, which retained more than 95% of its antigenicity after treatment for 1 minute. Only a high methylene chloride:water ratio was shown to slightly decrease toxoid antigenicity. Finally, no more than 3.3% of A21 desamido insulin and only traces of covalent insulin dimer were detected in nanoparticles. In conclusion, both the double emulsion and nanoprecipitation methods allowed efficient protein encapsulation. MALDI-TOF MS allowed accurate drug content determination. The manufacturing processes evaluated did not damage the primary structure of insulin.

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References

  1. Stevenson CL. Characterization of protein and peptide stability and solubility in non-aqueous solvents.Curr Pharm Biotechnol. 2000; 1:165–182.

    Article  CAS  Google Scholar 

  2. Bilati U, Allémann E, Doelker E. Development of a nanoprecipitation method intended for the entrapment of hydrophilic drugs into nanoparticles.Eur J Pharm Sci. 2005;24:67–75.

    Article  CAS  Google Scholar 

  3. Meyer JD, Manning MC. Hydrophobic ion pairing: altering the solubility properties of biomolecules.Pharm Res. 1998;15:188–193.

    Article  CAS  Google Scholar 

  4. Quintanar-Guerrero D, Allemann E, Fessi H, Doelker E. Applications of the ion-pair concept to hydrophilic substances with special emphasis on peptides.Pharm Res. 1997;14:119–127.

    Article  CAS  Google Scholar 

  5. Powers ME, Matsuura J, Brassel J, Manning MC, Shefter E. Enhanced solubility of proteins and peptides in nonpolar solvents through hydrophobic ion pairing.Biopolymers. 1993;33:927–932.

    Article  CAS  Google Scholar 

  6. Choi SH, Park TG. Hydrophobic ion pair formation between leuprolide and sodium oleate for sustained release from biodegradable polymeric microspheres.Int J Pharm. 2000;203:193–202.

    Article  CAS  Google Scholar 

  7. Quintanar-Guerrero D, Allémann E, Fessi H, Doelker E. Preparation techniques and mechanisms of formation of biodegradable nanoparticles from preformed polymers.Drug Dev Ind Pharm. 1998;24:1113–1128.

    CAS  Google Scholar 

  8. Fessi H, Puisieux F, Devissaguet J-Ph, Ammoury N, Benita S. Nanocapsule formation by interfacial polymer deposition following solvent displacement.Int J Pharm. 1989;55:R1-R4.

    Article  CAS  Google Scholar 

  9. Barichello JM, Morishita M, Takayama K, Nagai T. Encapsulation of hydrophilic and lipophilic drugs in PLGA nanoparticles by the nanoprecipitation method.Drug Dev Ind Pharm. 1999;25:471–476.

    Article  CAS  Google Scholar 

  10. Bilati U, Pasquarello C, Corthals GL, Hochstrasser DF, Allémann E, Doelker E. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for quantitation and molecular stability assessment of insulin entrapped within PLGA nanoparticles.J Pharm Sci. 2005; 94:688–694.

    Article  CAS  Google Scholar 

  11. Na DH, DeLuca PP, Lee KC. Direct determination of the peptide content in microspheres by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry.Anal Chem. 2004;76:2669–2673.

    Article  CAS  Google Scholar 

  12. Jiang G, Qiu W, DeLuca PP. Preparation and in vitro/in vivo evaluation of insulin-loaded poly(acryloyl-hydroxyethyl starch)-PLGA composite microspheres.Pharm Res. 2003;20:452–459.

    Article  CAS  Google Scholar 

  13. Capan Y, Jiang G, Giovagnoli S, Na KH, DeLuca PP. Preparation and Characterization of Poly(D,L-lactide-co-glycolide) Microspheres for Controlled Release of Human Growth Hormone.AAPS Pharm Sci Tech. 2003;4:E28.

    Article  Google Scholar 

  14. Yoo HS, Choi HK, Park TG. Protein-fatty acid complex for enhanced loading and stability within biodegradable nanoparticles.J Pharm Sci. 2001;90:194–201.

    Article  CAS  Google Scholar 

  15. Bilati U, Allémann E, Doelker E. Sonication parameters for the preparation of biodegradable nanocapsules of controlled size by the double emulsion method.Pharm Dev Technol. 2003;8:1–9.

    Article  CAS  Google Scholar 

  16. Bilati U, Allemann E, Doelker E. Protein-loaded nanoparticles prepared by the double emulsion method-processing and formulation issues for enhanced entrapment efficiency.J Microencapsul. 2005;22:205–214.

    Article  CAS  Google Scholar 

  17. Jung T, Koneberg R, Hungerer KD, Kissel T. Tetanus toxoid microspheres consisting of biodegradable poly(lactide-co-glycolide)-and ABA-triblock-copolymers: immune response in mice.Int J Pharm. 2002;234:75–90.

    Article  CAS  Google Scholar 

  18. Thomasin C, Corradin G, Men Y, Merkle HP, Gander B. Tetanus toxoid and synthetic malaria antigen containing poly(lactide)/poly(lactideco-glycolide) microspheres: importance of polymer degradation and antigen release for immune response.J Control Release. 1996;41:131–145.

    Article  CAS  Google Scholar 

  19. Nicoli S, Santi P, Couvreur P, Couarraze G, Colombo P, Fattal E. Design of triptorelin loaded nanospheres for transdermal iontophoretic administration.Int J Pharm. 2001;214:31–35.

    Article  CAS  Google Scholar 

  20. Men Y, Thomasin C, Merkle HP, Gander B, Corradin G. A single administration of tetanus toxoid in biodegradable microspheres elicits T cell and antibody responses similar or superior to those obtained with aluminum hydroxide.Vaccine. 1995;13:683–689.

    Article  CAS  Google Scholar 

  21. Alonso MJ, Gupta RK, Min C, Siber GR, Langer R. Biodegradable microspheres as controlled-release tetanus toxoid delivery systems.Vaccine. 1994;12:299–306.

    Article  CAS  Google Scholar 

  22. Tobio M, Nolley J, Guo Y, McIver J, Alonso MJ. A novel system based on a poloxamer/PLGA blend as a tetanus toxoid delivery vehicle.Pharm Res. 1999;16:682–688.

    Article  CAS  Google Scholar 

  23. Kang F, Jiang G, Hinderliter A, DeLuca PP, Singh J. Lysozyme stability in primary emulsion for PLGA microsphere preparation: effect of recovery methods and stabilizing excipients.Pharm Res. 2002; 19:629–633.

    Article  CAS  Google Scholar 

  24. Raghuvanshi RS, Goyal S, Singh O, Panda AK. Stabilization of dichloromethane-induced protein denaturation during microencapsulation.Pharm. Dev Technol. 1998;3:269–276.

    Article  CAS  Google Scholar 

  25. Tobio M, Alonso MJ. Study of the inactivation process of the tetanus toxoid in contact with poly(lactic/glycolic acid) degrading microspheres.STP Pharma Sci. 1998;8:303–310.

    CAS  Google Scholar 

  26. Gupta RK, Chang AC, Griffin P, Rivera R, Guo YY, Siber GR. Determination of protein loading in biodegradable polymer microspheres containing tetanus toxoid.Vaccine. 1997;15:672–678.

    Article  CAS  Google Scholar 

  27. Chang AC, Gupta RK. Stabilization of tetanus toxoid in poly(DL-lacticco-glycolic acid) microspheres for the controlled release of antigen.J Pharm Sci. 1996;85:129–132.

    Article  CAS  Google Scholar 

  28. Johansen P, Tamber H, Merkle HP, Gander B. Diphtheria and tetanus toxoid microencapsulation into conventional and endgroup alkylated PLA/PLGAs.Eur J Pharm Biopharm. 1999; 47:193–201.

    Article  CAS  Google Scholar 

  29. Falk R, Randolph TW, Meyer JD, Kelly RM, Manning MC. Controlled release of ionic compounds from poly(L-lactide) microspheres produced by precipitation with a compressed antisolvent.J Control Release. 1997;44:77–85.

    Article  CAS  Google Scholar 

  30. Jiang G, Woo BH, Kang F, Singh J, DeLuca PP. Assessment of protein release kinetics, stability and protein polymer interaction of lysozyme encapsulated poly (D,L-lactide-co-glycolide) microspheres.J Control Release. 2002;79:137–154.

    Article  CAS  Google Scholar 

  31. Chin JT, Wheeler SL, Klibanov AM. On protein solubility in organic solvents.Biotechnol Bioeng. 1994;44:140–145.

    Article  CAS  Google Scholar 

  32. Park TG, Lee HY, Nam YS. A new preparation method for protein loaded poly(D,L-lactic-co-glycolic acid) microspheres and protein release mechanism study.J Control Release. 1998;55:181–191.

    Article  CAS  Google Scholar 

  33. Matsuura J, Powers ME, Manning MC, Shefter E. Structure and stability of insulin dissolved in 1-octanol.J Am Chem Soc. 1993; 115:1261–1264.

    Article  CAS  Google Scholar 

  34. De Rosa G, Iommelli R, La Rotonda MI, Miro A, Quaglia F. Influence of the co-encapsulation of different non-ionic surfactants on the properties of PLGA insulin-loaded microspheres.J Control Release. 2000;69:283–295.

    Article  CAS  Google Scholar 

  35. Yeh MK. The stability of insulin in biodegradable microparticles based on blends of lactide polymers and polyethylene glycol.J Microencapsul. 2000;17:743–756.

    Article  CAS  Google Scholar 

  36. Uchida T, Nagareya N, Sakakibara S, et al. Preparation and characterization of polylactic acid microspheres containing bovine insulin by a w/o/w emulsion solvent evaporation method.Chem Pharm Bull (Tokyo). 1997;45:1539–1543.

    CAS  Google Scholar 

  37. Shao PG, Bailey LC. Porcine insulin biodegradable polyester microspheres: stability and in vitro release characteristics.Pharm Dev Technol. 2000;5:1–9.

    Article  CAS  Google Scholar 

  38. Uchida T, Yagi A, Oda Y, Nakada Y, Goto S. Instability of bovine insulin in poly(lactide-co-glycolide) (PLGA) microspheres.Chem Pharm Bull (Tokyo) 1996;44:235–236.

    CAS  Google Scholar 

  39. Kawashima Y, Yamamoto H, Takeuchi H, Fujioka S, Hino T. Pulmonary delivery of insulin with nebulized DL-lactide/glycolide copolymer (PLGA) nanospheres to prolong hypoglycemic effect.J Control Release. 1999;62:279–287.

    Article  CAS  Google Scholar 

  40. Brange J, Langkjaer L. Insulin structure and stability. In: Wang JY, Pearlman R, eds.Stability and Characterization of Protein and Peptide Drugs. New York, NY: Plenum Press; 1993:315–350.

    Google Scholar 

  41. Darrington RT, Anderson BD. Effects of insulin concentration and self-association on the partitioning of its A-21 cyclic anhydride intermediate to desamido insulin and covalent dimer.Pharm. Res. 1995;12:1077–1084.

    Article  CAS  Google Scholar 

  42. Darrington RT, Anderson BD. Evidence for a common intermediate in insulin deamidation and covalent dimer formation: effects of pH and aniline trapping in dilute acidic solutions.J Pharm Sci. 1995; 84:275–282.

    Article  CAS  Google Scholar 

  43. Hvass A, Hach M, Jars MU. Complementary analytical HPLC methods for insulin-related degradation products.Am Biotechnol Lab. 2003;21:8–10.

    CAS  Google Scholar 

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Correspondence to Eric Doelker.

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Published: December 1, 2005

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Bilati, U., Allémann, E. & Doelker, E. Nanoprecipitation versus emulsion-based techniques for the encapsulation of proteins into biodegradable nanoparticles and process-related stability issues. AAPS PharmSciTech 6, 74 (2005). https://doi.org/10.1208/pt060474

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