Recent advances in testing of microsphere drug delivery systems

References

• Shameem M, Lee H, DeLuca P. A short-term (accelerated release) approach to evaluate peptide release from PLGA depot formulations. AAPS PharmSciTech. 1999;1:1–6. doi:10.1208/ps010307.
   Google Scholar
• Park TG, Lu W, Crotts G. Importance of in vitro experimental conditions on protein release kinetics, stability and polymer degradation in protein encapsulated poly (D, L-lactic acid-co-glycolic acid) microspheres. J Control Release. 1995;33:211–222. DOI:10.1016/0168-3659(94)00084-8.
   Web of Science ®Google Scholar
• Shen J, Burgess DJ. Accelerated invitro release testing methods for extended release parenteral dosage forms. J Pharm Pharmacol. 2012;64:986–996. doi:10.1111/j.2042-7158.2012.01482.x.
   PubMed Web of Science ®Google Scholar
• Alagusundaram M, Madhu Sudana Chetty C, Umashankari K, et al. Microspheres as a novel drug delivery system - a review. Int J ChemTech Res. 2009;1:526–534.
   Google Scholar
• Nikam V, Gudsoorkar VR, Hiremath SN, et al. Microspheres - a novel drug delivery system: an overview. Int J Pharm Chem Sci. 2012;1:113–128.
   Google Scholar
• Namdev A, Issarani R, Khinchi MP. Microsphere as a novel drug delivery system: a review. Asian J Pharm Res Dev. 2015;3:15–24.
   Google Scholar
• Burgess DJ, Hickey AJ. Microsphere technology and applications. In: Swarbrick J, Boylan JC, editors. Encyclopedia of pharmaceutical technology. New York: Marcel Dekker; 1994. p. 1–29.
   Google Scholar
• Prajapati SK, Tripathi P, Ubaidulla U, et al. Design and development of gliclazide mucoadhesive microcapsules: in vitro and in vivo evaluation. AAPS PharmSciTech. 2008;9:224–230. doi:10.1208/s12249-008-9041-0.
   PubMed Web of Science ®Google Scholar
• Mukund J, Bhujbal R, Ranpise N. Floating microspheres: a review. Braz J Pharm Sci. 2012;48:17–30.
   Web of Science ®Google Scholar
• Kumar R, Palmieri MJ Jr. Points to consider when establishing drug product specifications for parenteral microspheres. Aaps J. 2010;12:27–32. DOI:10.1208/s12248-009-9156-6.
   PubMed Web of Science ®Google Scholar
• Rawat A, Burgess DJ. Effect of physical ageing on the performance of dexamethasone loaded PLGA microspheres. Int J Pharm. 2011;415:164–168. doi:10.1016/j.ijpharm.2011.05.067.
   PubMed Web of Science ®Google Scholar
• Kawashima Y, Niwa T, Takeuchi H, et al. Preparation of multiple unit hollow microspheres (microballoons) with acrylic resin containing tranilast and their drug release characteristics (in vitro) and floating behavior (in vivo). J Control Release. 1991;16:279–289. doi:10.1016/0168-3659(91)90004-W.
   Web of Science ®Google Scholar
• Kedzierewicz F, Thouvenot P, Lemut J, et al. Evaluation of peroral silicone dosage forms in humans by gamma- scintigraphy. J Control Release. 1999;58:195–205.
   PubMed Web of Science ®Google Scholar
• Jain SK, Agrawal GP, Jain NK. A novel calcium silicate based microspheres of repaglinide: in vivo investigations. J Control Release. 2006;113:111–116. doi:10.1016/j.jconrel.2006.04.005.
   PubMed Web of Science ®Google Scholar
• Jain SK, Agrawal GP, Jain NK. Evaluation of porous carrier-based floating orlistat microspheres for gastric delivery. AAPS PharmSciTech. 2006;7:E54–E62. doi:10.1208/pt070490.
   PubMed Web of Science ®Google Scholar
• Sato Y, Kawashima Y, Takeuchi H, et al. Pharmacoscintigraphic evaluation of riboflavin-containing microballoons for a floating controlled drug delivery system in healthy humans. J Control Release. 2004;98:75–85. doi:10.1016/j.jconrel.2004.04.021.
   PubMed Web of Science ®Google Scholar
• Cui F, Cun D, Tao A, et al. Preparation and characterization of melittin-loaded poly (DL-lactic acid) or poly (DL-lactic-co-glycolic acid) microspheres made by the double emulsion method. J Control Release. 2005;107:310–319.
   PubMed Web of Science ®Google Scholar
• Bhanja S, Sudhakar M, Neelima V, et al. development and evaluation of mucoadhesive microspheres of Irbesartan. Int J Pharm Res Health Sci. 2013;1:8–17.
   Google Scholar
• Reddy VM, Patil P, Biradar KV, et al. Development and evaluation of mucoadhesive microspheres of Nimodipine. Int Res J Pharm. 2011;2:91–98.
   Google Scholar
• Rathinaraj BS, Rajveer C, Sudharshini S, et al. Preparation and evaluation of mucoadhesive microcapsules of Nimodipne. Int J Res Pharmaceutics. 2010;1:219–224.
   Google Scholar
• Lehr C-M, Bouwstra JA, Tukker JJ, et al. Intestinal transit of bioadhesive microspheres in an in situ loop in the rat - a comparative study with copolymers and blends based on poly (acrylic acid). J Control Release. 1990;13:51–62. doi:10.1016/0168-3659(90)90074-4.
   Web of Science ®Google Scholar
• Rathore B, Yadav A, Nayak G, et al. A review on microspheres as drug delivery carriers for management of diabetes mellitus. Int J Pharm Life Sci. 2012;3:2064–2070.
   Google Scholar
• United States Pharmacopeia. National formulary general chapter <9467> organic volatile impurities. Rockville (MD): United States Pharmacopeial Convention; 2007.
   Google Scholar
• European Pharmacopoeia. European directorate for the quality of medicines and health care. Strasbourg: Council of Europe; 2011.
   Google Scholar
• ICH Harmonised Tripartite Guideline. Impurities: guideline for residual solvents Q3C(R5). International conference on harmonisation of technical requirements for registration of pharmaceuticals for human use; 2011 Feb 4; Geneva.
   Google Scholar
• Grodowska K, Parczewski A. Analytical methods for residual solvents determination in pharmaceutical products. Acta Pol Pharm Drug Res. 2010;67:13–26.
   PubMed Web of Science ®Google Scholar
• Shimura K, Zhi W, Matsumoto H, et al. Accuracy in the determination of isoelectric points of some proteins and a peptide by capillary isoelectric focusing: utility of synthetic peptides as isoelectric point markers. Anal Chem. 2000;72:4747–4757.
   PubMed Web of Science ®Google Scholar
• Lalwani S, Tutu E, Vigh G. Isoelectric buffers, part 3: determination of pKa and pI values of diamino sulfate carrier ampholytes by indirect UV-detection capillary electrophoresis. Electrophoresis. 2005;26:2503–2510. doi:10.1002/elps.200500002.
   PubMed Web of Science ®Google Scholar
• Righetti PG. Determination of the isoelectric point of proteins by capillary isoelectric focusing. J Chromatography A. 2004;1037:491–499.
   PubMed Web of Science ®Google Scholar
• 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.
   PubMed Web of Science ®Google Scholar
• Varcheh NN, Luginbuehl V, Aboofazeli R, et al. Preparing poly (lactic-co-glycolic acid)(PLGA) microspheres containing lysozyme-zinc precipitate using a modified double emulsion method. Iran J Pharm Res. 2011;10:203.
   PubMed Web of Science ®Google Scholar
• Park TG. Degradation of poly (D, L-lactic acid) microspheres: effect of molecular weight. J Control Release. 1994;30:161–173. doi:10.1016/0168-3659(94)90263-1.
   Web of Science ®Google Scholar
• Righetti PG, Gelfi C, Perego M, et al. Capillary zone electrophoresis of oligonucleotides and peptides in isoelectric buffers: theory and methodology. Electrophoresis. 1997;18:2145–2153. doi:10.1002/elps.1150181205.
   PubMed Web of Science ®Google Scholar
• Righetti PG, Gelfi C, Bossi A, et al. Capillary electrophoresis of peptides and proteins in isoelectric buffers: an update. Electrophoresis. 2000;21:4046–4053. doi:10.1002/1522-2683(200012)21:18<4046::AID-ELPS4046>3.0.CO;2-5.
   PubMed Web of Science ®Google Scholar
• Glukhovskiy PV, Vigh G. A simple method for the determination of isoelectric points of ampholytes with closely spaced pKa values using pressure-mediated capillary electrophoresis. Electrophoresis. 1998;19:3166–3170. doi:10.1002/elps.1150191819.
   PubMed Web of Science ®Google Scholar
• Kawatra M, Jain U, Ramana J. Recent advances in floating microspheres as gastro-retentive drug delivery system: a review. Int J Recent Adv Pharm Res. 2012;2:5–23.
   Google Scholar
• Chandna A, Batra D, Kakar S, et al. A review on target drug delivery: magnetic microspheres. J Acute Dis. 2013;2:189–195. doi:10.1016/S2221-6189(13)60125-0.
   Google Scholar
• Aklonis JJ, MacKnight WJ. Transitions and relaxations in amorphous polymers. In: Aklonis JJ, MacKnight WJ, editors. Introduction to polymer vis- coelasticity. 2nd ed. New York: Wiley-Interscience; 1983.
   Google Scholar
• Glavas-Dodov M, Goracinova K, Mladenovska K, et al. Release profile of lidocaine HCl from topical liposomal gel formulation. Int J Pharm. 2002;242:381–384.
   PubMed Web of Science ®Google Scholar
• Hitzman C, Wiedmann T, Dai H, et al. Measurement of drug release from microcarriers by microdialysis. J Pharm Sci. 2005;94:1456–1466. doi:10.1002/jps.20349.
   PubMed Web of Science ®Google Scholar
• Ruozi B, Tosi G, Forni F, et al. A. Ketorolac tromethamine lipo- somes: encapsulation and release studies. J Liposome Res. 2005;15:175–185. doi:10.1080/08982100500364214.
   PubMed Web of Science ®Google Scholar
• Sezer A, Baş A, Akbuğa J. Encapsulation of enrofloxacin in liposomes I: preparation and in vitro characterization of LUV. J Liposome Res. 2004;14:77–86. doi:10.1081/LPR-120039717.
   PubMed Web of Science ®Google Scholar
• Chidambaram N, Burgess DJ. A novel in vitro release method for submicron sized dispersed systems. AAPS PharmSciTech. 1999;1:E11.
   PubMed Web of Science ®Google Scholar
• Kokkona M, Kallinteri P, Fatouros D, et al. Stability of SUV lipo- somes in the presence of cholate salts and pancreatic lipases: effect of lipid composition. Eur J Pharm Sci. 2000;9:245–252.
   PubMed Web of Science ®Google Scholar
• Vemuri S, Yu C, Pushpala S, et al. Drug release rate method for a liposome preparation. Drug Dev Ind Pharm. 1991;17:183–192. doi:10.3109/03639049109043818.
   Web of Science ®Google Scholar
• Xiao C, Qi X, Maitani Y, et al. Sustained release of cisplatin from mul- tivesicular liposomes: potentiation of antitumor efficacy against S180 murine carcinoma. J Pharm Sci. 2004;93:1718–1724. DOI:10.1002/jps.20086.
   PubMed Web of Science ®Google Scholar
• Burgess DJ, Hussain AS, Ingallinera TS, et al. Assuring quality and performance of sustained and controlled release parenterals: workshop report. AAPS PharmSci. 2002;4:13–23. doi:10.1208/ps040205.
   Google Scholar
• Wei Y, Zhao L. In vitro and in vivo evaluation of ranitidine hydrochloride loaded hollow microspheres in rabbits. Arch Pharm Res. 2008;31:1369–1377. doi:10.1007/s12272-001-2119-9.
   PubMed Web of Science ®Google Scholar
• Murty SB, Goodman J, Thanoo BC, et al. Identification of chemically modified peptide from poly (D, L-lactide-co-glycolide) microspheres under in vitro release conditions. AAPS PharmSciTech. 2003;4:392–405. doi:10.1208/pt040450.
   Google Scholar
• Kadajji GV, Betageri GV, Venkatesan N. Approaches for dissolution testing of novel drug delivery systems. Am Pharm Rev. 2011;14(6):38–44.
   Google Scholar
• Kostanski JW, DeLuca P. A novelin vitro release technique for peptide-containing biodegradable microspheres. AAPS PharmSciTech. 2000;1(1):30–40.
   Google Scholar
• Burgess DJ, Crommelin DJA, Hussain AJ, et al. EUFEPS workshop report, assuring quality and performance of sustained and controlled release parenterals. Eur J Pharm Sci. 2004;21:679–690.
   PubMedGoogle Scholar
• Zolnik BS, Raton J-L, Burgess DJ. Application of USP apparatus 4 and in situ fiber optic analysis to microsphere release testing. Dissolut Technol. 2005;12:11–14. doi:10.14227/DT210314P1.
   Google Scholar
• Voisine J, Zolnik B, Burgess DJ. In situ fiber optic method for long-term in vitro release testing of microspheres. Int J Pharm. 2008;356:206–211. doi:10.1016/j.ijpharm.2008.01.017.
   PubMed Web of Science ®Google Scholar
• Bhardwaj U, Burgess DJ. A novel USP apparatus 4 based release testing method for dispersed systems. Int J Pharm. 2010;388:287–294. doi:10.1016/j.ijpharm.2010.01.009.
   PubMed Web of Science ®Google Scholar
• Zolnik BS, Leary PE, Burgess DJ. Elevated temperature accelerated release testing of PLGA microspheres. J Control Release. 2006;112:293–300. doi:10.1016/j.jconrel.2006.02.015.
   PubMed Web of Science ®Google Scholar
• Zolnik BS, Burgess DJ. Effect of acidic pH on PLGA microsphere degradation and release. J Control Release. 2007;122:338–344. DOI:10.1016/j.jconrel.2007.05.034.
   PubMed Web of Science ®Google Scholar
• D’Souza SS, Faraj JA, DeLuca PP. A model-dependent approach to correlate accelerated with real-time release from biodegradable microspheres. AAPS PharmSciTech. 2005;6:E553–64. doi:10.1208/pt060470.
   PubMedGoogle Scholar
• Miyajima M, Koshika A, Okada J, et al. Mechanism of drug release from poly(L-lactic acid) matrix containing acidic or neutral drugs. J Control Release. 1999;60:199–209.
   PubMed Web of Science ®Google Scholar
• Siepmann J, Faisant N, Akiki J, et al. Effect of the size of biodegradable microparticles on drug release: experiment and theory. J Control Release. 2004;96:123–134. doi:10.1016/j.jconrel.2004.01.011.
   PubMed Web of Science ®Google Scholar
• Liggins RT, Burt HM. Paclitaxel loaded poly(L-lactic acid) (PLLA) microspheres. II. The effect of processing parameters on microsphere morphology and drug release kinetics. Int J Pharm. 2004;281:103–106. doi:10.1016/j.ijpharm.2004.05.027.
   PubMed Web of Science ®Google Scholar
• Dunne M, Corrigan OI, Ramtoola Z. Influence of particle size and dissolution conditions on the degradation properties of polylactide-co-glycolide particles. Biomaterials. 2000;21:1659–1668.
   PubMed Web of Science ®Google Scholar
• Gumusderelioglu M, Deniz G. Sustained release of mitomycin-C from poly (DL-lactide)/poly (DL-lactide-co-glycolide) films. J Biomater Sci Polym Ed. 2000;11:1039–1050. doi:10.1163/156856200743562.
   PubMed Web of Science ®Google Scholar
• Ehtezazi T, Washington C. Controlled release of macromolecules from PLA microspheres: using porous structure topology. J Control Release. 2000;68:361–372.
   PubMed Web of Science ®Google Scholar
• Bittner B, Witt C, Mäder K, et al. Degradation and protein release properties of microspheres prepared from biodegradable poly (lactide-co-glycolide) and ABA triblock copolymers: influence of buffer media on polymer erosion and bovine serum albumin release. J Control Release. 1999;60:297–309.
   PubMed Web of Science ®Google Scholar
• Kamberi M, Nayak S, Myo-Min K, et al. A novel accelerated in vitro release method for biodegradable coating of drug eluting stents: insight to the drug release mechanisms. Eur J Pharm Sci. 2009;37:217–222. DOI:10.1016/j.ejps.2009.02.009.
   PubMed Web of Science ®Google Scholar
• Siewert M, Dressman J, Burgess DJ, et al. FIP/AAPS guidelines to dissolution/in vitro release testing of novel/special dosage forms. AAPS PharmSciTech. 2003;4:43–52. doi:10.1208/pt040107.
   Google Scholar
• Costa P, Lobo JMS. Modeling and comparison of dissolution profiles. Eur J Pharm Sci. 2001;13:123–133.
   PubMed Web of Science ®Google Scholar
• Joseph N, Lakshmi S, Jayakrishnan A. A floating- type oral dosage form for piroxicam based on hollow polycarbonate microspheres: in vitro and in vivo evaluation in rabbits. J Control Release. 2002;79:71–79.
   PubMed Web of Science ®Google Scholar
• Hickey T, Kreutzer D, Burgess DJ, et al. In vivo evaluation of a dexamethasone/PLGA microsphere system designed to suppress the inflammatory tissue response to implantable medical devices. J Biomed Mater Res. 2002;61:180–187. doi:10.1002/jbm.10016.
   PubMed Web of Science ®Google Scholar
• Sato Y, Kawashima Y, Takeuchi H, et al. In vivo evaluation of riboflavin-containing microballoons for floating controlled drug delivery system in healthy human volunteers. J Control Release. 2003;93:39–47.
   PubMed Web of Science ®Google Scholar
• Hakkarainen M, Albertsson A-C, Karlsson S. Weight losses and molecular weight changes correlated with the evolution of hydroxyacids in simulated in vivo degradation of homo- and copolymers of PLA and PGA. Polym Degrad Stab. 1996;52:283–291. doi:10.1016/0141-3910(96)00009-2.
   Web of Science ®Google Scholar
• D’Souza SS, Faraj JA, Giovagnoli S, et al. IVIVC from long acting Olanzapine microspheres. Int J Biomater. 2014;2014:1–11. doi:10.1155/2014/407065.
   Google Scholar
• Agrawal CM, Huang D, Schmitz JP, et al. Elevated temperature degradation of a 50: 50 copolymer of PLA-PGA. Tissue Eng. 1997;3:345–352. doi:10.1089/ten.1997.3.345.
   Google Scholar
• Aso Y, Yoshioka S, Liwanpo ALW, et al. Effect of temperature on mechanisms of drug release and matrix degradation of poly (D, L-lactide) microspheres. J Control Release. 1994;31:33–39. doi:10.1016/0168-3659(94)90248-8.
   Web of Science ®Google Scholar
• Jiang G, Woo BH, Kang F, et al. Assessment of protein release kinetics, stability and protein polymer interaction of lysozyme encapsulated poly (D, L-lactide-co-glycolide) microspheres. J Control Release. 2002;79:137–145.
   PubMed Web of Science ®Google Scholar
• Li S, Girard A, Garreau H, et al. Enzymatic degradation of polylactide stereocopolymers with predominant D-lactyl contents. Polym Degrad Stab. 2000;71:61–67. doi:10.1016/S0141-3910(00)00152-X.
   Web of Science ®Google Scholar
• Makino K, Ohshima H, Kondo T. Mechanism of hydrolytic degradation of poly (L-lactide) microcapsules: effects of pH, ionic strength and buffer concentration. J Microencapsul. 1986;3:203–212. doi:10.3109/02652048609031574.
   PubMedGoogle Scholar
• FDA. Guidance for Industry: extended release oral dosage forms: development, evaluation and application of in vitro/in vivo correlation. Rockville (MD): U.S. department of health and human services, food and drug administration, center for drug evaluation and research; 1997.
   Google Scholar
• Schliecker G, Schmidt C, Fuchs S, et al. In vitro and in vivo correlation of buserelin release from biodegradable implants using statistical moment analysis. J Control Release. 2004;94:25–37.
   PubMed Web of Science ®Google Scholar
• Blanco-Prieto MJ, Besseghir K, Zerbe O, et al. In vitro and in vivo evaluation of a somatostatin analogue released from PLGA microspheres. J Control Release. 2000;67:19–28.
   PubMed Web of Science ®Google Scholar
• Urata T, Arimori K, Nakano M. Modification of release rates of cyclosporin A from polyl (L-lactic acid) microspheres by fatty acid esters and in-vivo evaluation of the microspheres. J Control Release. 1999;58:133–141.
   PubMed Web of Science ®Google Scholar
• Blanco-Prieto MJ, Campanero MA, Besseghir K, et al. Importance of single or blended polymer types for controlled in vitro release and plasma levels of a somatostatin analogue entrapped in PLA/PLGA microspheres. J Control Release. 2004;96:437–448. doi:10.1016/j.jconrel.2004.02.015.
   PubMed Web of Science ®Google Scholar
• Lam XM, Duenas ET, Daugherty AL, et al. Sustained release of recombinant human insulin-like growth factor-I for treatment of diabetes. J Control Release. 2000;67:281–292.
   PubMed Web of Science ®Google Scholar
• Yoo HS, Lee KH, Oh JE, et al. In vitro and in vivo anti-tumor activities of nanoparticles based on doxorubicin-PLGA conjugates. J Control Release. 2000;68:419–431.
   PubMed Web of Science ®Google Scholar
• Feng L, Qi XR, Zhou XJ, et al. Pharmaceutical and immunological evaluation of a single-dose hepatitis B vaccine using PLGA microspheres. J Control Release. 2006;112:35–42. doi:10.1016/j.jconrel.2006.01.012.
   PubMed Web of Science ®Google Scholar
• Hinds KD, Campbell KM, Holland KM, et al. PEGylated insulin in PLGA microparticles. In vivo and in vitro analysis. J Control Release. 2005;104:447–460. doi:10.1016/j.jconrel.2005.02.020.
   PubMed Web of Science ®Google Scholar
• Liu WH, Song JL, Liu K, et al. Preparation and in vitro and in vivo release studies of Huperzine A loaded microspheres for the treatment of Alzheimer’s disease. J Control Release. 2005;107:417–427. doi:10.1016/j.jconrel.2005.03.025.
   PubMed Web of Science ®Google Scholar
• Mundargi RC, Srirangarajan S, Agnihotri SA, et al. Development and evaluation of novel biodegradable microspheres based on poly (d, l-lactide-co-glycolide) and poly (ε-caprolactone) for controlled delivery of doxycycline in the treatment of human periodontal pocket: in vitro and in vivo studies. J Control Release. 2007;119:59–68. doi:10.1016/j.jconrel.2007.01.008.
   PubMed Web of Science ®Google Scholar
• Zhong H, Deng Y, Wang X, et al. Multivesicular liposome formulation for the sustained delivery of breviscapine. Int J Pharm. 2005;301:15–24. doi:10.1016/j.ijpharm.2005.04.001.
   PubMed Web of Science ®Google Scholar
• Young D, Farrell C, Shepard T. In vitro/in vivo correlation for modified release injectable drug delivery systems. B. D. J. injectable dispersed systems: formulation, processing and performance. Boca Raton: Taylor & Francis; 2005. p. 159–176.
   Google Scholar
• Zolnik BS, Burgess DJ. In vitro in vivo correlation on parenteral dosage forms. In: Biopharmaceutics applications in drug development. New York: Springer; 2008. p. 336–358.
   Google Scholar
• Rawat A, Bhardwaj U, Burgess DJ. Comparison of in vitro–in vivo release of Risperdal® Consta® microspheres. Int J Pharm. 2012;434:115–121. doi:10.1016/j.ijpharm.2012.05.006.
   PubMed Web of Science ®Google Scholar
• Shen J, Burgess DJ, et al. In vitro-in vivo correlation of parenteral risperidone polymeric microspheres. J Control Release. 2015;218:2–12. doi:10.1016/j.jconrel.2015.09.051.
   PubMed Web of Science ®Google Scholar
• Bajaj S, Singla D, Sakhuja N. Stability testing of pharmaceutical products. J Appl Pharm Sci. 2012;02(03):129–138.
   Google Scholar
• Puthli S, Vavia P. Stability studies of microparticulate system with piroxicam as model drug. AAPS PharmSciTech. 2009;10:872–880. doi:10.1208/s12249-009-9280-8.
   PubMed Web of Science ®Google Scholar
• Allison SD. Effect of structural relaxation on the preparation and drug release behavior of poly(lactic-co-glycolic) acid microparticle drug delivery systems. J Pharm Sci. 2008;97:2022–2035. doi:10.1002/(ISSN)1520-6017.
   PubMed Web of Science ®Google Scholar
• White JR. Polymer ageing: physics, chemistry or engineering? Time to reflect. Comptes Rendus Chimie. 2006;9:1396–1408. doi:10.1016/j.crci.2006.07.008.
   Web of Science ®Google Scholar
• Bailey NA, Sandor M, Kreitz M, et al. Comparison of the enthalpic relaxation of poly(lactide-co-glycolide) 50:50 nanospheres and raw polymer. J Appl Polym Sci. 2002;86:1868–1872. doi:10.1002/app.11109.
   Web of Science ®Google Scholar
• Liu Y, Bhandari B, Zhou W. Glass transition and enthalpy relax- ation of amorphous food saccharides: a review. J Agric Food Chem. 2006;54:5701–5717. doi:10.1021/jf060188r.
   PubMed Web of Science ®Google Scholar
• Hancock BC, Zografi G. The relationship between the glass transition temperature and the water content of amorphous pharmaceutical solids. Pharm Res. 1994;11:471–477.
   PubMed Web of Science ®Google Scholar
• Baig F, Mohammed GA. Formulation and evaluation of controlled release ketoprofen microspheres. Int J Reseach Pharm Biomeidical Sci. 2012;3:1168–1172.
   Google Scholar
• Tyagi LK, Kori ML. Stability study and in-vivo evaluation of lornoxicam loaded ethyl cellulose microspheres. Int J Pharm Sci Drug Res. 2014;6:26–30.
   PubMedGoogle Scholar
• Wang Y, Burgess DJ. Influence of storage temperature and moisture on the performance of microsphere/hydrogel composites. Int J Pharm. 2013;454:310–315. doi:10.1016/j.ijpharm.2013.06.012.
   PubMed Web of Science ®Google Scholar
• Kaiser N, Kimpfler A, Massing U, et al. 5-Fluorouracil in vesicular phospholipid gels for anticancer treatment: entrapment and release properties. Int J Pharm. 2003;256:123–131.
   PubMed Web of Science ®Google Scholar
• Sayin B, Calis S. Influence of accelerated storage conditions on the stability of vancomycin-loaded poly(D,L-lactide-co- glycolide) microspheres. J Pharm Sci. 2004;29:111–116.
   Google Scholar
• De S, Robinson DH. Particle size and temperature effect on the physical stability of PLGA nanospheres and microspheres containing bodipy. AAPS PharmSciTech. 2004;5:18–24. DOI:10.1208/pt050453.
   Web of Science ®Google Scholar
• Lewis L, Bonis RL, Adeyeyes CM. The physical and chemical stability of suspensions of sustained-release diclofenac microspheres. J Microencapsulation: Micro-Nano Carriers. 1998;15:555–567. doi:10.3109/02652049809008240.
   PubMed Web of Science ®Google Scholar