共查询到20条相似文献,搜索用时 62 毫秒
1.
Jessica J. Hung Barton J. Dear Aileen K. Dinin Ameya U. Borwankar Sumarth K. Mehta Thomas T. Truskett Keith P. Johnston 《Pharmaceutical research》2018,35(7):133
Purpose
To explain the effects of the osmolyte proline on the protein-protein interactions (PPI), viscosity and stability of highly concentrated antibody solutions in contrast to other neutral osmolytes.Methods
The viscosity of ~225 mg/mL mAb solutions was measured with proline, glycine and trehalose as a function of pH and co-solute concentration up to 1.3 M. The stability was assessed via turbidity as well as size exclusion chromatography after 4 weeks storage at 40°C. The PPI strength was assessed qualitatively via the high concentration diffusion rate by dynamic light scattering.Results
Increasing proline significantly reduced the mAb viscosity and increased the colloidal stability at pH 6, but not at pH 5 further from the mAb pI. In contrast, glycine and trehalose did not improve the viscosity nor stability. The normalized diffusion coefficient at high concentration, which is inversely proportional to the attractive PPI strength, increased with proline concentration but decreased with increasing glycine.Conclusions
Proline demonstrated greater efficacy for improving mAb viscosity and stability in contrast to glycine and trehalose due to its amphipathic structure and partial charge on the pyrrolidine side chain. These properties likely allow proline to screen the attractive electrostatic and hydrophobic interactions that promote self-association and high viscosities. Binary proline-histidine formulations also demonstrated greater viscosity reduction effects than histidine alone at the same total co-solute concentration, while maintaining a lower total solution osmolarity.2.
Wei-Jie Fang Wei Qi John Kinzell Steven Prestrelski John F. Carpenter 《Pharmaceutical research》2012,29(12):3278-3291
Purpose
To evaluate the effects of several buffers and excipients on the stability of glucagon during freeze-drying and storage as dried powder formulations.Methods
The chemical and physical stability of glucagon in freeze-dried solid formulations was evaluated by a variety of techniques including mass spectrometry (MS), reversed phase HPLC (RP-HPLC), size exclusion HPLC (SE-HPLC), infrared (IR) spectroscopy, differential scanning calorimetry (DSC) and turbidity.Results
Similar to protein drugs, maintaining the solid amorphous phase by incorporating carbohydrates as well as addition of surfactant protected lyophilized glucagon from degradation during long-term storage. However, different from proteins, maintaining/stabilizing the secondary structure of glucagon was not a prerequisite for its stability.Conclusions
The formulation lessons learned from studies of freeze-dried formulations of proteins can be applied successfully to development of stable formulations of glucagon. However, peptides may behave differently than proteins due to their small molecule size and less ordered structure. 相似文献3.
Jihea Park Karthik Nagapudi Camille Vergara Ranjini Ramachander Jennifer S. Laurence Sampathkumar Krishnan 《Pharmaceutical research》2013,30(4):968-984
Purpose
To investigate the mechanism of IgG1 mAb stabilization after freeze-drying and the interdependence of protein structural preservation in the solid state, glassy state dynamics and long-term storage stability under different formulation conditions.Methods
IgG1 mAb was formulated with mannitol at pH 3.0, 5.0, and 7.0 in the presence and absence of sucrose and stability was monitored over 1 year at different temperatures. Physical and covalent degradation of lyophilized formulation was monitored using SEC, CEX, and light obscuration technique. Secondary and tertiary structure of the protein in the solid state was characterized using FTIR and fluorescence spectroscopy respectively. Raman spectroscopy was also used to monitor changes in secondary and tertiary structure, while SS-NMR 1H relaxation was used to monitor glassy state dynamics.Results
IgG1 mAb underwent significant secondary structural perturbations at pH 3.0 and conditions without sucrose, while pH 5.0 condition with sucrose showed the least structural change over time. The structural changes correlated with long-term stability with respect to protein aggregate formation and SbVP counts. SS-NMR data showed reduced relaxation time at conditions that were more stable.Conclusions
Native state protein structural preservation and optimal solid-state dynamics correlate with improved long-term stability of the mAb in the different lyophilized formulations. 相似文献4.
Mosbæk CR Konarev PV Svergun DI Rischel C Vestergaard B 《Pharmaceutical research》2012,29(8):2225-2235
Purpose
Concentrated protein formulations are strongly influenced by protein-protein interactions. These can be probed at low protein concentration by e.g. virial coefficients. It was recently suggested that interactions are attractive at short distances and repulsive at longer distances. Measurements at low concentrations mainly sample longer distances, hence may not predict high concentration behavior. Here we demonstrate that small angle X-ray scattering (SAXS) measurements simultaneously collect information on interactions at short and long distances.Methods
IgG2 antibody samples at concentrations up to 122?mg/ml are analyzed using SAXS and compared to Circular Dichroism (CD), Fluorescence, Size Exclusion Chromatography (SEC) and Dynamic Light Scattering (DLS) analysis.Results
DLS and SEC analyses reveal attraction between antibodies at high concentrations. SAXS data analysis provides an elaborate understanding and shows both attractive and repulsive forces. The protein-protein interactions are strongly affected by excipients. No change in the solution state of IgG2 is observed at pH 4?C8, while samples at pH 3 exhibit heavy oligomerization. The solution conformation of the examined IgG2 derived from SAXS data is a T-shape.Conclusion
SAXS analysis resolves simultaneous attractive and repulsive interactions, and details the effect of excipients on the interactions, while providing three-dimensional structural information from low-concentration samples. 相似文献5.
Kishore RS Kiese S Fischer S Pappenberger A Grauschopf U Mahler HC 《Pharmaceutical research》2011,28(5):1194-1210
Purpose
To study the potential impact of the degradation of Polysorbates (PS) 20 and 80 on the stability of therapeutic proteins in parenteral formulations.Method
First, degradation products of PS20 and 80 were identified. Subsequently, the effect of degraded polysorbate on physical characteristics and long-term stability of protein formulations was assessed. Further, the impact of polysorbate degradation on protein stability was evaluated via shaking stress studies on formulations spiked with artificially degraded polysorbate or degradants like fatty acids. Additionally, aged formulations with reduced polysorbate content were shaken.Results
The degradation of polysorbate leads to a buildup of various molecules, some of which are poorly soluble, including fatty acids and polyoxyethylene (POE) esters of fatty acids. Spiking studies showed that the insoluble degradants could potentially impact protein stability and that the presence of sufficient intact polysorbate was crucial to prevent this. End-of-shelf-life shaking of protein formulations showed that the stability of various monoclonal antibodies was, however, not affected.Conclusions
Although some degradants can potentially influence the stability of the protein (as discerned from spiking studies), degradation of polysorbates did not impact the stability of the different proteins tested in pharmaceutically relevant temperature and storage conditions. 相似文献6.
Armin Mooranian Rebecca Negrulj Sangeetha Mathavan Jorge Martinez Jessica Sciarretta Nigel Chen-Tan TK Mukkur Momir Mikov Mladena Lalic-Popovic Maja Stojančević Svetlana Golocorbin-Kon Hani Al-Salami 《Journal of pharmaceutical innovation》2014,9(2):150-157
Introduction
In previous studies carried out in our laboratory, a bile acid (BA) formulation exerted a hypoglycaemic effect in a rat model of type-1 diabetes (T1D). When the antidiabetic drug gliclazide (G) was added to the bile acid, it augmented the hypoglycaemic effect. In a recent study, we designed a new formulation of gliclazide-cholic acid (G-CA), with good structural properties, excipient compatibility and exhibits pseudoplastic-thixotropic characteristics. The aim of this study is to test the slow release and pH-controlled properties of this new formulation. The aim is also to examine the effect of CA on G release kinetics at various pH values and different temperatures.Method
Microencapsulation was carried out using our Buchi-based microencapsulating system developed in our laboratory. Using sodium alginate (SA) polymer, both formulations were prepared: G-SA (control) and G-CA-SA (test) at a constant ratio (1:3:30), respectively. Microcapsules were examined for efficiency, size, release kinetics, stability and swelling studies at pH 1.5, pH 3, pH 7.4 and pH 7.8 and temperatures of 20 and 30 °C.Results
The new formulation is further optimised by the addition of CA. CA reduced microcapsule swelling of the microcapsules at pH 7.8 and pH 3 at 30 °C and pH 3 at 20 °C, and, even though microcapsule size remains similar after CA addition, percent G release was enhanced at high pH values (pH 7.4 and pH 7.8, p?<?0.01).Conclusion
The new formulation exhibits colon-targeted delivery and the addition of CA prolonged G release suggesting its suitability for the sustained and targeted delivery of G and CA to the lower intestine. 相似文献7.
Mohammed M. Ibrahim Abd-Elgawad H. Abd-Elgawad Osama A. Soliman Monica M. Jablonski 《Pharmaceutical research》2013,30(11):2818-2831
Purpose
Preparation of topical ophthalmic formulations containing brimonidine-loaded nanoparticles prepared from various biodegradable polymers—PCL, PLA and PLGA—for sustained release of brimonidine as a once daily regimen for management of glaucoma.Methods
Nanoparticles were prepared using spontaneous emulsification solvent diffusion method then characterized regarding their particle size, zeta potential, morphology and drug contents. Brimonidine-loaded nanoparticles were incorporated into eye drops, temperature-triggered in situ gelling system and preformed gel and characterized regarding their pH, viscosity, uniformity of drug contents, in vitro release study, in vitro cytotoxicity and in vivo intraocular pressure (IOP) lowering effects.Results
The results of optimized brimonidine-loaded PCL-, PLGA- and PLA-NPs respectively, are: particle sizes of 117.33?±?4.58 nm, 125.67?±?5.15 nm and 131.67?±?3.79 nm; zeta potentials of ?18.5?±?2.87 mV, ?21.82?±?2.7 mV and ?28.11?±?2.21 mV; and encapsulation efficiencies of 77.97?±?1.38%, 68.65?±?3.35% and 73.52?±?2.92%. TEM analyses revealed that all NPs have spherical shapes with dense core and distinct coat. In vitro release data showed a sustained release without any burst effect with Higuchi non-Fickian diffusion mechanism. Cytotoxicity studies revealed that all formulations are non-toxic. Also all formulations possessed a sustained IOP lowering effect compared to Alphagan® P eye drops.Conclusions
Our formulations showed prolonged management of glaucoma that should meet with better patient compliance as a once-daily formulation. 相似文献8.
Scott A. Burton Chin-Yee Ng Ryan Simmers Craig Moeckly David Brandwein Tom Gilbert Nathan Johnson Ken Brown Tesha Alston Gayatri Prochnow Kris Siebenaler Kris Hansen 《Pharmaceutical research》2011,28(1):31-40
Purpose
The purpose of this work is to demonstrate rapid intradermal delivery of up to 1.5 mL of formulation using a hollow microneedle delivery device designed for self-application.Methods
3M??s hollow Microstructured Transdermal System (hMTS) was applied to domestic swine to demonstrate delivery of a variety of formulations including small molecule salts and proteins. Blood samples were collected after delivery and analyzed via HPLC or ELISA to provide a PK profile for the delivered drug. Site evaluations were conducted post delivery to determine skin tolerability.Results
Up to 1.5 mL of formulation was infused into swine at a max rate of approximately 0.25 mL/min. A red blotch, the size of the hMTS array, was observed immediately after patch removal, but had faded so as to be almost indistinguishable 10 min post-patch removal. One-mL deliveries of commercial formulations of naloxone hydrochloride and human growth hormone and a formulation of equine anti-tetanus toxin were completed in swine. With few notable differences, the resulting PK profiles were similar to those achieved following subcutaneous injection of these formulations.Conclusions
3M??s hMTS can provide rapid, intradermal delivery of 300?C1,500 µL of liquid formulations of small molecules salts and proteins, compounds not typically compatible with passive transdermal delivery. 相似文献9.
Sharvil S. Patil Edakkal Venugopal Suresh Bhat Kakasaheb R. Mahadik Anant R. Paradkar 《Pharmaceutical research》2013,30(7):1906-1914
Purpose
To investigate influence of ion induced mesophasic transformation on pharmaceutical performance of in situ gelling system consisting of glyceryl monooleate.Methods
The prepared system showed mesophasic transformation during its conversion from sol to gel upon controlled hydration. The process of mesophasic transformation was studied by SAXS, DSC, rheology and plane polarized light microscopy. Further the influence of additives i.e. naproxen salts (sodium and potassium) and naproxen (base) on the process of mesophasic transformation was also elucidated.Results
It was observed that addition of salt form of naproxen transformed W/O emulsions into cubic mesophase whereas addition of base form of naproxen formed reverse hexagonal (HII) phase upon controlled hydration. The cubic mesophase formed by naproxen salts retarded the drug release for initial 3 h whereas HII phase showed sustained drug release characteristics for naproxen base following Higuchi drug release kinetics.Conclusion
The current work suggests that formulations with tailor made pharmaceutical performance can be developed by selecting proper additives in the system so as to obtain the desired mesophase ‘on demand’ thereby controlling drug release characteristics.? 相似文献
10.
Purpose
The present study explores the potential of bicontinous cubic liquid crystalline nanoparticles (LCNPs) for improving therapeutic potential of doxorubicin.Methods
Phytantriol based Dox-LCNPs were prepared using hydrotrope method, optimized for various formulation components, process variables and lyophilized. Structural elucidation of the reconstituted formulation was performed using HR-TEM and SAXS analysis. The developed formulation was subjected to exhaustive cell culture experiments for delivery potential (Caco-2 cells) and efficacy (MCF-7 cells). Finally, in vivo pharmacokinetics, pharmacodynamic studies in DMBA induced breast cancer model and cardiotoxicity were also evaluated.Results
The reconstituted formulation exhibited Pn3m type cubic structure, evident by SAXS and posed stability in simulated gastrointestinal fluids and at accelerated stability conditions for 6 months. Dox-LCNPs revealed significantly higher cell cytotoxicity (16.23-fold) against MCF-7 cell lines as compared to free drug owing to its preferential localization in the vicinity of nucleus. Furthermore, Caco-2 cell experiments revealed formation of reversible “virtual pathways” in the cell membrane for Dox-LCNPs and hence posed significantly higher relative oral bioavailability (17.74-fold). Subsequently, Single dose of Dox-LCNPs (per oral) led to significant reduction in % tumor burden (~42%) as compared that of ~31% observed in case of Adriamycin® (i.v.) when evaluated in DMBA induced breast cancer model. Moreover, Dox induced cardiotoxicity was also found to be significantly lower in case of Dox-LCNPs as compared to clinical formulations (Adriamycin® and Lipodox®).Conclusion
Incorporation of Dox in the novel LCNPs demonstrated improved antitumor efficacy and safety profile and can be a viable option for oral chemotherapy. 相似文献11.
Jian Hua Gu Alice Beekman Tian Wu Deirdre Murphy Piedmonte Priti Baker Michael Eschenberg Michael Hale Merrill Goldenberg 《Pharmaceutical research》2013,30(2):387-401
Purpose
A novel application of oscillatory shear rheology was used to directly monitor global phase behavior of protein formulations in the frozen state and study its correlation with physical instability of frozen protein formulations.Methods
Oscillatory rheology was used to measure changes in rheological parameters and to identify mechanical softening temperature (Ts*) and related properties of an IgG2 mAb formulation. Rheological measurements were compared to DSC/MDSC. Physical stability of IgG2 formulations was monitored by SE-HPLC.Results
Rheological parameters and Ts* of an IgG2 formulation were sensitive to physical/morphological phase changes during freezing and thawing. Ts* of the frozen formulation was a function of concentration of protein and excipient. Complex modulus, G*, and phase angle, δ, for IgG2 at 70 mg/mL in a sucrose-containing formulation showed the system was not completely frozen at ?10°C, which correlated to stability data consistent with ice-induced protein aggregation.Conclusions
We report the first application of oscillatory shear rheology to study phase behavior of IgG2 in a sucrose-containing formulation and its correspondence with physical stability not explained by glass transition (Tg’). We provide a mechanism and data suggesting that protein instability occurs at the ice/water interface. 相似文献12.
Phillip M. Lovalenti Jeff Anderl Luisa Yee Van Nguyen Behnaz Ghavami Satoshi Ohtake Atul Saxena Thomas Voss Vu Truong-Le 《Pharmaceutical research》2016,33(5):1144-1160
Purpose
The goal of this research is to develop stable formulations for live attenuated influenza vaccines (LAIV) by employing the drying methods freeze drying, spray drying, and foam drying.Methods
Formulated live attenuated Type-A H1N1 and B-strain influenza vaccines with a variety of excipient combinations were dried using one of the three drying methods. Process and storage stability at 4, 25 and 37°C of the LAIV in these formulations was monitored using a TCID50 potency assay. Their immunogenicity was also evaluated in a ferret model.Results
The thermal stability of H1N1 vaccine was significantly enhanced through application of unique formulation combinations and drying processes. Foam dried formulations were as much as an order of magnitude more stable than either spray dried or freeze dried formulations, while exhibiting low process loss and full retention of immunogenicity. Based on long-term stability data, foam dried formulations exhibited a shelf life at 4, 25 and 37°C of >2, 1.5 years and 4.5 months, respectively. Foam dried LAIV Type-B manufactured using the same formulation and process parameters as H1N1 were imparted with a similar level of stability.Conclusion
Foam drying processing methods with appropriate selection of formulation components can produce an order of magnitude improvement in LAIV stability over other drying methods.13.
Rashmin B. Patel Mrunali R. Patel Kashayap K. Bhatt Bharat G. Patel 《Journal of pharmaceutical innovation》2013,8(3):195-204
Purpose
This paper describes formulation considerations and in vitro evaluation of a microemulsion drug delivery system designed for intranasal administration of Paliperidone.Methods
Drug-loaded microemulsions were successfully prepared by a water titration. Prepared formulations were subjected to physicochemical characterization, and evaluated for in vitro diffusion, nasal cilio toxicity, and in vitro mucoadhesion.Results
The microemulsion, containing 4 % oleic acid, 30 % surfactant mixture of [Labrasol/Cremophor RH 40 (1:1)]/[Transcutol P] (3:1) and 66 % (wt/wt) aqueous phase, that displayed a 99.93 % optical transparency, globule sizes of 20.01?±?1.28 nm, and a polydispersity index of 0.117?±?0.034 was selected for the incorporation of polyelectrolytic polymer (polycarbophil) as the mucoadhesive component. The mucoadhesive microemulsion formulation of Paliperidone that contains 0.5 % by weight of polycarbophil displayed higher in vitro mucoadhesive potential (18.0?±?2.5 min) and diffusion coefficient (3.83?×?10?6?±?0.019?×?10?6) than microemulsion. Also, they were found to be free from nasal ciliotoxicity and had stability for 6 months.Conclusion
The in vitro studies demonstrated the potential of developing mucoadhesive microemulsion formulation for intranasal delivery of Paliperidone. 相似文献14.
Shuntaro Saito Jun Hasegawa Naoki Kobayashi Toshiaki Tomitsuka Susumu Uchiyama Kiichi Fukui 《Pharmaceutical research》2013,30(5):1263-1280
Purpose
To develop a general strategy for optimizing monoclonal antibody (MAb) formulations.Methods
Colloidal stabilities of four representative MAbs solutions were assessed based on the second virial coefficient (B 2) at 20°C and 40°C, and net charges at different NaCl concentrations, and/or in the presence of sugars. Conformational stabilities were evaluated from the unfolding temperatures. The aggregation propensities were determined at 40°C and after freeze–thawing. The electrostatic potential of antibody surfaces was simulated for the development of rational formulations.Results
Similar B 2 values were obtained at 20°C and 40°C, implying little dependence on temperature. B 2 correlated quantitatively with aggregation propensities at 40°C. The net charge partly correlated with colloidal stability. Salts stabilized or destabilized MAbs, depending on repulsive or attractive interactions. Sugars improved the aggregation propensity under freeze–thaw stress through improved conformational stability. Uneven and even distributions of potential surfaces were attributed to attractive and strong repulsive electrostatic interactions.Conclusions
Assessment of colloidal stability at the lowest ionic strength is particularly effective for the development of formulations. If necessary, salts are added to enhance the colloidal stability. Sugars further improved aggregation propensities by enhancing conformational stability. These behaviors are rationally predictable according to the surface potentials of MAbs. 相似文献15.
Sandra Reichstetter Gerardo M. Castillo Israel Rubinstein Akiko Nishimoto-Ashfield ManShun Lai Cynthia C. Jones Aryamitra Banjeree Alex Lyubimov Duane C. Bloedow Alexei Bogdanov Jr. Elijah M. Bolotin 《Pharmaceutical research》2013,30(3):670-682
Purpose
To determine and compare pharmacokinetics and toxicity of two nanoformulations of Vasoactive Intestinal Peptide (VIP).Methods
VIP was formulated using a micellar (Sterically Stabilized Micelles, SSM) and a polymer-based (Protected Graft Copolymer, PGC) nanocarrier at various loading percentages. VIP binding to the nanocarriers, pharmacokinetics, blood pressure, blood chemistry, and acute maximum tolerated dose (MTD) of the formulations after injection into BALB/c mice were determined.Results
Both formulations significantly extend in vivo residence time compared to unformulated VIP. Formulation toxicity is dependent on loading percentage, showing major differences between the two carrier types. Both formulations increase in vivo potency of unformulated VIP and show acute MTDs at least 140 times lower than unformulated VIP, but still at least 100 times higher than the anticipated highest human dose, 1–5 μg/kg. These nanocarriers prevented a significant drop in arterial blood pressure compared to unformulated VIP.Conclusions
While both carriers enhance in vivo residence time compared to unformulated VIP and reduce the drop in blood pressure immediately after injection, PGC is the excipient of choice to extend residence time and improve the safety of potent therapeutic peptides such as VIP.Pharmacokinetics of VIP after SC injection of 100 μg/kg in BALB/c mice (n?=?5). (a) Overview of entire 72 h sampling period, (b) the first 6 h shown in detail. VIP quantitation in serum samples was by competitive ELISA. LOD: level of detection. 相似文献
16.
Changcheng?Zhu Yoko?Shoji Scott?McCray Michael?Burke Caitlin?E.?Hartman Jessica?A.?Chichester Jeff?Breit Vidadi?Yusibov Dexiang?Chen Manjari?Lal
Purpose
Stable vaccines with long shelf lives and reduced dependency on the cold chain are ideal for stockpiling and rapid deployment during public emergencies, including pandemics. Spray drying is a low-cost process that has potential to produce vaccines stable at a wide range of temperatures. Our aim was to develop a stable formulation of a recombinant H1N1 influenza hemagglutinin vaccine candidate and take it to pilot-scale spray-drying production.Methods
Eight formulations containing different excipients were produced and assayed for antigen stability, powder characteristics, and immunogenicity after storage at a range of temperatures, resulting in the identification of four promising candidates. A pilot-scale spray-drying process was then developed for further testing of one formulation.Results
The pilot-scale process was used to reproducibly manufacture three batches of the selected formulation with yields >90%. All batches had stable physical properties and in vitro potency for 6 months at temperatures from ?20°C to +50°C. Formulations stored for 3 months elicited immunogenic responses in mice equivalent to a frozen lot of bulk vaccine used as a stability control.Conclusions
This study demonstrates the feasibility of stabilizing subunit vaccines using a spray-drying process and the suitability of the process for manufacturing a candidate product.17.
Shubhadra N. Singh Sandeep Yadav Steven J. Shire Devendra S. Kalonia 《Pharmaceutical research》2014,31(9):2549-2558
Purpose
The purpose of this study was to investigate the contribution of the dipole moment to overall protein-protein interactions and viscosity of a monoclonal antibody MAb1.Methods
The dipole moment of MAb1 was measured at various solution pH conditions using dielectric relaxation spectroscopy.Results
The dipole moment for MAb1 was highest at pH 6.5, and the pH dependent change in molecular dipole correlated fairly well with previously observed trends of viscosity and storage modulus versus pH. Moreover, the magnitude of the dielectric increment at pH 6.5 and 7.0 showed strong concentration dependence, indicating the presence of relatively strong dipole-dipole interactions at these pHs. To test if the cluster of charged residues present in the Fab contributes to the mean dipole moment observed for MAb1, additional mutants involving charge mutations in the CDR were investigated. In contrast to MAb1, all of the other MAbs showed significantly reduced pH and concentration dependence of the measured dipole moments and dielectric increments, respectively.Conclusions
The solution pH dependent measured dipole moments of MAb1 appears to be in line with the observed intermolecular interactions and viscosity behavior suggesting that dipole-dipole interaction plays an important role in governing the high concentration solution behavior of this MAb. 相似文献18.
Purpose
We hypothesize that ultrasonication can accelerate solute crystallization in freeze-concentrates. Our objective is to demonstrate ultrasonication as a potential predictive tool for evaluating physical stability of excipients in frozen solutions.Methods
The crystallization tendencies of lyoprotectants (trehalose, sucrose), carboxylic acid buffers (citric, tartaric, malic, and acetic) and an amino acid buffer (histidine HCl) were studied. Aqueous solutions of buffers, lyoprotectants and mixtures of the two were cooled from room temperature to ?20°C and sonicated to induce solute crystallization. The crystallized phases were identified by X-ray diffractometry (laboratory or synchrotron source).Results
Sonication accelerated crystallization of trehalose dihydrate in frozen trehalose solutions. Sonication also enhanced solute crystallization in tartaric (200 mM; pH 5), citric (200 mM pH 4) and malic (200 mM; pH 4) acid buffers. At lower buffer concentrations, longer annealing times following sonication were required to facilitate solute crystallization. The time for crystallization of histidine HCl progressively increased as a function of sucrose concentration. The insonation period required to effect crystallization also increased with sucrose concentration.Conclusions
Sonication can substantially accelerate solute crystallization in the freeze-concentrate. Ultrasonication may be useful in assessing the crystallization tendency of formulation constituents used in long term frozen storage and freeze-drying. 相似文献19.
Stefan Dengl Marc Wehmer Friederike Hesse Florian Lipsmeier Oliver Popp Kurt Lang 《Pharmaceutical research》2013,30(5):1380-1399
Purpose
To investigate antibody stability and formation of modified species under upstream processing conditions.Methods
The stability of 11 purified monoclonal human IgG1 and IgG4 antibodies, including an IgG1-based bispecific CrossMab, was compared in downscale mixing stress models. One of these molecules was further evaluated in realistic bioreactor stress models and in cell culture fermentations. Analytical techniques include size exclusion chromatography (SEC), turbidity measurements, cation exchange chromatography (cIEX), dynamic light scattering (DLS) and differential scanning calorimetry (DSC).Results
Sensitivity in downscale stress models varies among antibodies and results in formation of high molecular weight (HMW) aggregates. Stability is increased in cell culture medium and in bioreactors. Media components stabilizing the proteins were identified. Extensive chemical modifications were detected both in stress models as well as during production of antibodies in cell culture fermentations.Conclusions
Protective compounds must be present in chemically defined fermentation media in order to stabilize antibodies against the formation of HMW aggregates. An increase in chemical modifications is detectable in bioreactor stress models and over the course of cell culture fermentations; this increase is dependent on the expression rate, pH, temperature and fermentation time. Consequently, product heterogeneity increases during upstream processing, and this compromises the product quality. 相似文献20.