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Extractables and Leachables Evaluations for Filters
Published in Maik W. Jornitz, Filtration and Purification in the Biopharmaceutical Industry, 2019
Raymond H. Colton, Denise G. Bestwick
There are certain formulations that lead to irresolvable analytical interference or negatively alter the analytical performance of the instruments thereby making the results unreliable. An example of a common additive often used as a solubilizing agent in pharmaceutical formulations is Triton X-100. Triton X-100 (Figure 13.6b) is a surfactant with an eight-carbon alkyl chain (saturated hydrocarbon), a phenyl group (aromatic-ring), 10 unit polyoxyethylene chain (multiple ethyl esters), and a hydroxyl group. The combination of oliophilic (oil loving) groups and hydrophilic (water loving) groups make it ideal to keep drugs or biopharmaceutical ingredients that have limited water solubility in solution. The same properties that make Triton X-100 useful for solubilizing drugs also make it effective at solubilizing leachables from polymers. In addition, sample preparation steps such as SPE and LLE retain the Triton X-100 along with the leachables. Figure 13.8a shows an HPLC chromatogram of a 20% aqueous solution of Triton X-100. The analytical interference is dramatic and in this specific example, ruined the HPLC column and contaminated the entire HPLC system. Figure 13.8b shows the HPLC chromatogram for 0.1% (1,000 ppm) Triton X-100. There is substantial interference from 13 to 17 min. There is still significant interference at 0.01% (100 ppm) as shown in Figure 13.8c. Only when the concentration is reduced to 0.001% (10 ppm) is the analytical interference reduced to negligible as shown in Figure 13.8d.
Downstream processing of viral-based vaccines
Published in Amine Kamen, Laura Cervera, Bioprocessing of Viral Vaccines, 2023
Rita P. Fernandes, Piergiuseppe Nestola, Cristina Peixoto
Viruses used for vaccination are generally produced by cell infection, and their release is dependent upon the virus cycle since they can be found intra- or extra-cellularly. In the case of lytic viruses assembled intra-cellularly, a cell lysis step is necessary to release the neosynthetized particles as for adenovirus or adeno-associated virus. Such cell lysis or cell disruption is thus performed prior or after clarification step. It can be performed by mechanical (homogenization, sonication) or chemical (freeze-thaw cycles, detergent addition) methods [16]. Considering adenovirus manufacturing, at a laboratory scale, the purification process consists of a cell lysis step using freeze and thaw methodologies, followed by density gradient ultracentrifugation and a final desalting step [17,18]. This process is successful at a small scale, achieving high purity level while maintaining a low total to infectious viral particle ratio (below 30). However, this methodology has strong limitations associated with the processing time and scalability. This is why cell lysis at a larger scale is commonly performed by the addition of detergents [19]. One detergent widely used is a mild non-ionic detergent known as Triton X-100. It solubilizes the cell membranes allowing the viruses release. Several other applications of Triton X-100, commonly formulated at 0.1% exist, as the protein solubilization, the viral sub-unit preparation, and the enveloped virus inactivation [20,21]. However, there is evidence that Triton X-100 can have undesirable effects on the environment due to endocrine disruption properties during its degradation. Thus, it was added to the REACH (Registration, Evaluation, Authorisation and Restrictions of Chemicals) list, forbidding its use from 4 January 2021, forcing the companies to work on eco-friendly substitutes. One alternative recently reported was Polysorbate 20, which is a stable, non-toxic, and non-ionic surfactant widely used in domestic and pharmaceutical applications [22]. In this work, the efficacy of Polysorbate 20 was evaluated and compared with Triton X-100. Results showed no negative effects on the adenovirus’s purification train and an increased virus recovery and impurities’ removal. Other alternatives, such as sodium deoxycholate for the AAVs’ purification [23] and CHAPS for adenovirus’s purification [24] have already been applied. Nevertheless, detergents added to the culture should be removed, as they can have an impact on the next downstream operation. The increase in virus yield thus obtained should compensate for the extra efforts to achieve the required purification level for the viral vaccine.
Experimental and numerical investigation of diffusion absorption refrigeration system working with ZnOAl2O3 and TiO2 nanoparticles added ammonia/water nanofluid
Published in Experimental Heat Transfer, 2022
Emine Yağız Gürbüz, Adnan Sözen, Ali Keçebaş, Engin Özbaş
The nanoparticle concentrations are prepared for use in nanofluid with a nanoparticle content of 2% and 1% (wt/wt). Then, prepared nanoparticles are added into the ammonia/water as the base fluid. In this preparation stage, a surfactant must be added to the system due to reduce the interaction between the particles and activate the repulsion forces in order to maintain stability of the nanoparticles [26, 41]. The suspensions are enhanced by adding Triton X-100 surface-active agent of 0.5% (wt./wt.). Triton X-100 was originally a registered trademark of Rohm and Haas Co. Triton X-100 (the closed molecular formula) is C14H22O(C2H4O)n as a nonionic and clear viscous fluid surfactant. Lastly, other essential part of preparation started with ultrasonic bath. The ultrasonic bath should be maintained for at least three hours for each solution. Consequently, TiO2 and ZnOAL2O3 nanoparticles can be suspended in the base fluid for a longer time by means of ultrasonic bath and surfactant addition.
Effect of Nanofluid and Surfactant on Thermosyphon Heat Pipe Performance
Published in Heat Transfer Engineering, 2020
Hamid Ghorabaee, Mohammad Reza Sarmasti Emami, Maryam Shafahi
Preparation of nanofluid is the first key step in the experimental investigations. TiO2 was used as nanomaterial due to its excellent photocatalysis properties and high thermal conductivity which has been widely studied [37]. To prepare the nanofluid, TiO2 nanoparticles (20 nm, provided by the US Research Nanomaterial Inc.) were well dispersed into the distilled water (DW) as a base fluid at mass concentrations of 0.3, 0.5, 0.8, 1, 1.2 wt%. Nanofluid was mixed with the TS, with the concentrations of 0.1, 0.2, 0.3vt%. Triton X-100 is a nonionic surfactant which decreases the surface tension of the fluids. The two-step method was used to prepare the nano-suspensions which is the most common method in this field based on the literature [38–41]. In this study two effective methods were used to stabilize the suspension against the sedimentation of the nanoparticles. These methods are: (i) use of ultrasonic processor, (ii) addition of surfactant. The TiO2 nanoparticles were dispersed in DW by using the horn ultrasonic homogenizer at 24 kHz, 1200 W and 50 °C for 5 h. Figure 1 shows the SEM (TESCAN, model VEGA (II) LMH, Czech Republic) image of dried nanofluid (TiO2+water).
Experimental comparison of Triton X-100 and sodium dodecyl benzene sulfonate surfactants on thermal performance of TiO2–deionized water nanofluid in a thermosiphon
Published in Experimental Heat Transfer, 2018
Adnan Sözen, Metin Gürü, Tayfun Menlik, Uğur Karakaya, Erdem Çiftçi
The sodium dodecyl benzene sulfonate (SDBS, C18H29NaO3S) is an anionic solid surfactant like a salt and the major components of the laundry detergents [58]. However, Triton X-100, whose chemical formula is (C14H22O(C2H4O)n), is both nonionic and clear viscous fluid surfactant. It is added particularly into a media to bring down the surface tension. By reducing the surface tension, it is intended that fluid surfaces are all rescued from the surface tension effects since the fluid surfaces under the tensile effects depict diversified properties from the other part of the fluid. The anionic characteristics and hydrophilic structure of SDBS led to rise the hanging time of the nano-particles into the aqueous solution.