Impact of Poloxamer 188 Material Attributes on Proteinaceous Visible Particle Formation in Liquid Monoclonal Antibody Formulations.

Surfactants such as Poloxamer 188 (PX188) play an important role in controlling particle formation in biotherapeutic formulations due to interfacial stresses. This study demonstrates for the first time that hydrophobicity of PX188 is a potential critical material attribute (CMA) as far as control of visible particle (VP) formation is concerned. We have found that within PX188 lots satisfying pharmacopeial specifications, there is variability in material attributes such as hydrophobicity, as determined from their reversed-phase high-performance liquid chromatography profiles.

Hydration/Dehydration Behavior of Hydroxyethyl Cellulose Ether in Aqueous Solution.

Hydroxyethyl cellulose (HeC) maintains high water solubility over a wide temperature range even in a high temperature region where other nonionic chemically modified cellulose ethers, such as methyl cellulose (MC) and hydroxypropylmethyl cellulose (HpMC), demonstrate cloud points. In order to clarify the reason for the high solubility of HeC, the temperature dependence of the hydration number per glucopyranose unit, , for the HeC samples was examined by using extremely high frequency dielectric spectrum measuring techniques up to 50 GHz over a temperature range from 10 to 70 °C. HeC samples with a molar substitution number () per glucopyranose unit by hydroxyethyl groups ranging from 1.

Reconsideration of the conformation of methyl cellulose and hydroxypropyl methyl cellulose ethers in aqueous solution.

The structure and conformation of methyl cellulose (MC) and hydroxypropyl methyl cellulose (HpMC) ether samples dissolved in dilute aqueous (DO) solutions at a temperature of 25 °C were reconsidered in detail based on the experimental results obtained using small- and wide-angle neutron scattering (S-WANS) techniques in a range of scattering vectors () from 0.05 to 100 nm. MC samples exhibited an average degree of substitution (DS) by methyl groups per glucose unit of DS = 1.

Molecular motions, structure and hydration behaviour of glucose oligomers in aqueous solution.

The degree of polymerization and temperature dependencies of the molecular motions, configuration and hydration behaviour of glucose oligomers (Gn, n = 2 to 7, degree of polymerization) in aqueous solutions were investigated using extremely high-frequency dielectric spectrum measuring techniques up to 50 GHz. The obtained dielectric spectra for the aqueous Gn solutions were well decomposed into four Debye-type relaxation modes. The fastest relaxation mode j = 1 was assigned to the rotational process of free water molecules in the sample solution.

Transport Properties of Commercial Cellulose Nanocrystals in Aqueous Suspension Prepared from Chemical Pulp via Sulfuric Acid Hydrolysis.

A cellulose nanocrystal (CNC) sample prepared from chemical pulp via sulfuric acid hydrolysis procedures has been supplied by InnoTech Alberta Inc. in the shape of white dry powder as a prototype product. Some transport coefficients were precisely investigated for the CNC sample in aqueous suspensions at the room temperature of 25 °C such as the average rotational and translational diffusion coefficients ( and ) and viscoelastic relaxation times (τ) at dilute conditions.

Pronounced Dielectric and Hydration/Dehydration Behaviors of Monopolar Poly(N-alkylglycine)s in Aqueous Solution.

Poly(N-methylglycine) (NMGn) and poly(N-ethylglycine) (NEGn) obtained by polymerization reactions initiated by benzylamine have no carboxy termini, such as those in normal polyamides, but have only amino termini, which exist primarily as cations in aqueous media at a pH value of ca. 9.5, observed in aqueous solutions without any buffer reagents.