Impact of Polysorbate 80 Grade on the Interfacial Properties and Interfacial Stress Induced Subvisible Particle Formation in Monoclonal Antibodies.

Polysorbate 80 is a nonionic surfactant that is added to therapeutic protein formulations to mitigate protein particle formation when subjected to various mechanical stresses. Variations in the PS80 grade has recently sparked questions surrounding the effect of oleic acid content (OAC) on surfactant's ability to mitigate interface-induced protein particle formation when stressed. In this work, a Langmuir trough was used to apply interfacial dilatational stress to two IgG molecules (mAb1 and mAb2) in formulations containing Chinese pharmacopeia (CP) and multicompendial (MC) grades of PS80.

Cross-linking of poly (vinyl alcohol) films under acidic and thermal stress.

Poly (vinyl alcohol), PVA, a commonly used excipient to coat tablets, forms insoluble films in the presence of acids and thermal stress. This may lead to drug products failing to meet dissolution specifications over time. Studies were conducted to understand the effect of acid strength, processing conditions, and storage stress on the mechanism of insoluble film formation using PVA and Opadry II as model systems.

Bridging size and charge variants of a therapeutic monoclonal antibody by two-dimensional liquid chromatography.

Monoclonal antibodies are heterogeneous in nature and may contain numerous variants with differences in size, charge, and hydrophobicity, which may impact clinical efficacy, immunogenicity, and safety. Characterization of antibody variants is necessary to build structure-function correlation and establish a proper control strategy. Isolation and enrichment of variants by conventional chromatographic peak fractionation is labor-intensive and time-consuming.

Assessing the risk of drug crystallization in vivo.

Introduction: Low intrinsic solubility leading to poor oral bioavailability is a common challenge in drug discovery that can often be overcome by formulation strategies, however, it remains a potential limitation that can pose challenges for early risk assessment and represent a significant obstacle to drug development. We identified a selective inhibitor (BMS-986126) of the IL-1 receptor-associated kinase 4 (IRAK4) with favorable properties as a lead candidate, but with unusually low intrinsic solubility of <1 μg/mL.

Methods: Conventional histopathology identified the issue of crystal formation in vivo.

Understanding Protein-Interface Interactions of a Fusion Protein at Silicone Oil-Water Interface Probed by Sum Frequency Generation Vibrational Spectroscopy.

Protein adsorbed at the silicone oil-water interface can undergo a conformational change that has the potential to induce protein aggregation on storage. Characterization of the protein structures at interface is therefore critical for understanding the protein-interface interactions. In this article, we have applied sum frequency generation (SFG) spectroscopy for studying the secondary structures of a fusion protein at interface and the surfactant effect on protein adsorption to silicone oil-water interface.

Characterization of a Liquid Crystal System for Sustained Release of a Peptide BMS-686117.

Liquid crystal lipid-based formulations are an effective approach to prolong pharmacokinetics and reduce burst release of a drug on subcutaneous delivery. The objective of this paper was to investigate the influence of phase structures of a lipid-based liquid crystal delivery system and its associated mechanical properties on the release profile of a peptide. It was hypothesized that release of drug molecules are closely related to the mechanical properties that are controlled by phase structures.

The Impact of Disintegrant Type, Surfactant, and API Properties on the Processability and Performance of Roller Compacted Formulations of Acetaminophen and Aspirin.

In formulation development, certain excipients, even though used in small quantities, can have a significant impact on the processability and performance of the dosage form. In this study, three common disintegrants, croscarmellose sodium (CCS), crospovidone (xPVP), and sodium starch glycolate (SSG) as well as the surfactant sodium lauryl sulfate (SLS) were evaluated for their impact on the processability and performance of a typical dry granulation formulation. Two model compounds, the mechanically brittle and chemically inert acetaminophen and the mechanically ductile carboxylic acid aspirin, were used for the evaluation.

Characterization of Phase Separation Propensity for Amorphous Spray Dried Dispersions.

A generalized screening approach, applying isothermal calorimetry at 37 °C 100% RH, to formulations of spray dried dispersions (SDDs) for two active pharmaceutical ingredients (APIs) (BMS-903452 and BMS-986034) is demonstrated. APIs 452 and 034, with similar chemotypes, were synthesized and promoted during development for oral dosing. Both APIs were formulated as SDDs for animal exposure studies using the polymer hydroxypropylmethlycellulose acetyl succinate M grade (HPMCAS-M).

The effect of polymeric excipients on the physical properties and performance of amorphous dispersions: Part I, free volume and glass transition.

Purpose: To investigate the structural effect of polymeric excipients on the behavior of free volume of drug-polymer dispersions in relation to glass transition.

Methods: Two drugs (indomethacin and ketoconazole) were selected to prepare amorphous dispersions with PVP, PVPVA, HPC, and HPMCAS through spray drying. The physical attributes of the dispersions were characterized using SEM and PXRD.

Low level drug product API form analysis - Avalide tablet NIR quantitative method development and robustness challenges.

Avalide(@), a medication used for the treatment of hypertension, is a combination of Irbesartan, and Hydrochlorothiazide. Irbesartan, one of the active pharmaceutical ingredients (API) in Avalide products, exists in two neat crystalline forms: Form A and Form B. Irbesartan Form A is the API form used in a wet granulation for the preparation of Avalide tablets.

Anharmonic vibrational calculations modeling the raman spectra of intermediates in the photoactive yellow protein (PYP) photocycle.

The role of anharmonic effects in the vibrational spectroscopy of the dark state and two major chromophore intermediates of the photoactive yellow protein (PYP) photocycle is examined via ab initio vibrational self-consistent field (VSCF) calculations and time-resolved resonance Raman spectroscopy. For the first time, anharmonicity is considered explicitly in calculating the vibrational spectra of an ensemble consisting of the PYP chromophore surrounded by model compounds used as mimics of the important active-site residues. Predictions of vibrational frequencies on an ab initio corrected semiempirical potential energy surface show remarkable agreement with experimental frequencies for all three states, thus shedding light on the potential along the reaction path.

Combined spectroscopic and topographic characterization of nanoscale domains and their distributions of a redox protein on bacterial cell surfaces.

Redox protein nanoscale domains on the cell surface of a bacterium, Shewanella oneidensis MR1, grown in the absence and presence of electron acceptors, is topographically characterized using combined atomic force microscopy (AFM) and confocal surface enhanced Raman scattering (SERS) spectroscopy. The protruding nanoscale domains on the outer membrane of S. oneidensis were observed, as was their disappearance upon exposure to electron acceptors such as oxygen, nitrate, fumarate, and iron nitrilotriacetate (FeNTA).

Probing inhomogeneous vibrational reorganization energy barriers of interfacial electron transfer.

An atomic force microscopy (AFM) and confocal Raman microscopy study of the interfacial electron transfer of a dye-sensitization system, i.e., alizarin adsorbed upon TiO(2) nanoparticles, has revealed the distribution of the mode-specific vibrational reorganization energies encompassing different local sites ( approximately 250-nm spatial resolution).

Nitric oxide binding to prokaryotic homologs of the soluble guanylate cyclase beta1 H-NOX domain.

The heme cofactor in soluble guanylate cyclase (sGC) is a selective receptor for NO, an important signaling molecule in eukaryotes. The sGC heme domain has been localized to the N-terminal 194 amino acids of the beta1 subunit of sGC and is a member of a family of conserved hemoproteins, called the H-NOX family (Heme-Nitric Oxide and/or OXygen-binding domain). Three new members of this family have now been cloned and characterized, two proteins from Legionella pneumophila (L1 H-NOX and L2 H-NOX) and one from Nostoc punctiforme (Np H-NOX).

Characterization of functional heme domains from soluble guanylate cyclase.

Soluble guanylate cyclase (sGC) is a heterodimeric, nitric oxide (NO)-sensing hemoprotein composed of two subunits, alpha1 and beta1. NO binds to the heme cofactor in the beta1 subunit, forming a five-coordinate NO complex that activates the enzyme several hundred-fold. In this paper, the heme domain has been localized to the N-terminal 194 residues of the beta1 subunit.

Spectroscopic characterization of the soluble guanylate cyclase-like heme domains from Vibrio cholerae and Thermoanaerobacter tengcongensis.

Soluble guanylate cyclase (sGC) is a nitric oxide- (NO-) sensing hemoprotein that has been found in eukaryotes from Drosophila to humans. Prokaryotic proteins with significant homology to the heme domain of sGC have recently been identified through genomic analysis. Characterization of two of these proteins is reported here.

Time-resolved resonance raman structural studies of the pB' intermediate in the photocycle of photoactive yellow protein.

Time-resolved resonance Raman spectroscopy is used to obtain chromophore vibrational spectra of the pR, pB', and pB intermediates during the photocycle of photoactive yellow protein. In the pR spectrum, the C8-C9 stretching mode at 998 cm(-1) is approximately 60 cm(-1) lower than in the dark state, and the combination of C-O stretching and C7H=C8H bending at 1283 cm(-1) is insensitive to D2O substitution. These results indicate that pR has a deprotonated, cis chromophore structure and that the hydrogen bonding to the chromophore phenolate oxygen is preserved and strengthened in the early photoproduct.

Picosecond dynamics of G-protein coupled receptor activation in rhodopsin from time-resolved UV resonance Raman spectroscopy.

The protein response to retinal chromophore isomerization in the visual pigment rhodopsin is studied using picosecond time-resolved UV resonance Raman spectroscopy. High signal-to-noise Raman spectra are obtained using a 1 kHz Ti:Sapphire laser apparatus that provides <3 ps visible (466 nm) pump and UV (233 nm) probe pulses. When there is no time delay between the pump and probe events, tryptophan modes W18, W16, and W3 exhibit decreased Raman scattering intensity.

Time-resolved resonance Raman analysis of chromophore structural changes in the formation and decay of rhodopsin's BSI intermediate.

Time-resolved resonance Raman microchip flow experiments are performed to obtain the vibrational spectrum of the chromophore in rhodopsin's BSI intermediate and to probe structural changes in the bathorhodopsin-to-BSI and BSI-to-lumirhodopsin transitions. Kinetic Raman spectra from 250 ns to 3 micros identify the key vibrational features of BSI. BSI exhibits relatively intense HOOP modes at 886 and 945 cm(-1) that are assigned to C(14)H and C(11)H=C(12)H A(u) wags, respectively.