A systematic study of CSTD-generated stress on different biomolecular modalities.

Although Closed System Transfer Devices (CSTDs) are used in oncology for dose preparation and administration, the impact of CSTDs on biologics and other non-small molecular modalities are not fully understood. We investigated particle formation when preparing and mock administering three experimental biologics (mAb, ADC, and fusion protein) using seven models of CSTDs. A wide range of visible and subvisible particle formation was observed among CSTD models.

A Practical Tool for Risk-Based In-use Compatibility Assessments.

In drug development, in-use compatibility studies are crucial steps to ensure that the critical quality attributes of the drug product are maintained when in contact with administration components. But once the drug is in clinical trials, unanticipated variations in these components can stretch limited resources and lengthen timelines to market, as these changes must be assessed and approved to ensure continued patient safety. It's desirable to use a science-based risk evaluation to determine the extent of data and testing needed in these situations, but there is no standard for how such evaluations are done.

Assessment of compatibility of rhIGF-1/rhIGFBP-3 with neonatal intravenous medications.

Background: Recombinant human (rh)IGF-1/IGFBP-3 protein complex, administered as a continuous intravenous infusion in preterm infants, is being studied for the prevention of complications of prematurity.

Methods: We conducted in vitro studies to evaluate the physical and chemical compatibility of rhIGF-1/IGFBP-3 with medications routinely administered to preterm neonates. In vitro mixing of rhIGF-1/IGFBP-3 drug product with small-molecule test medications plus corresponding controls was performed.

Development of Protein-Specific Analytical Methodologies to Evaluate Compatibility of Recombinant Human (rh)IGF-1/rhIGFBP-3 with Intravenous Medications Co-Administered to Neonates.

The protein complex of recombinant human insulin-like growth factor-1 and insulin‑like growth factor binding protein‑3 (rhIGF-1/rhIGFBP-3; mecasermin rinfabate), is an investigational product for the prevention of complications of prematurity. Delivery of rhIGF-1/rhIGFBP-3 is by continuous central line intravenous infusion in preterm infants until endogenous IGF-1 production begins. Protein-specific analytical methodologies were developed to evaluate the compatibility of rhIGF-1/rhIGFBP-3 at low protein concentrations (∼2.

Freeze-thaw characterization process to minimize aggregation and enable drug product manufacturing of protein based therapeutics.

Physical instabilities of proteins in the form of protein aggregation continue to be a major challenge in the development of protein drug candidates. Aggregation can occur during different stages of product lifecycle such as freeze-thaw, manufacturing, shipping, and storage, and can potentially delay commercialization of candidates. A lack of clear understanding of the underlying mechanism(s) behind protein aggregation and the potential immunogenic reactions renders the presence of aggregates in biotherapeutic products undesirable.

Self-buffering capacity of a human sulfatase for central nervous system delivery.

Direct delivery of therapeutic enzymes to the Central Nervous System requires stringent formulation design. Not only should the formulation design consider the delicate balance of existing ions, proteins, and osmolality in the cerebrospinal fluid, it must also provide long term efficacy and stability for the enzyme. One fundamental approach to this predicament is designing formulations with no buffering species.

Self-association of human beta-galactocerebrosidase: Dependence on pH, salt, and surfactant.

Krabbe disease, also known as globoid cell leukodystrophy, is a rare genetic neurodegenerative disease caused by a deficiency of the galactocerebrosidase enzyme. To understand the association status of human beta-galactocerebrosidase (hGALC) in solution, we employed analytical ultracentrifugation (AUC). Our AUC results show that hGALC has a tendency for reversible self-association.

Residual Host Cell Protein Promotes Polysorbate 20 Degradation in a Sulfatase Drug Product Leading to Free Fatty Acid Particles.

This study investigated the root cause behind an observed free fatty acid particle formation and resulting Polysorbate 20 (PS20) loss for a sulfatase drug product upon long-term storage at 5 ± 3°C. Reversed- phase chromatography with mass spectrometric analysis as well as charged aerosol detection was used to characterize the peaks associated with the intact and degraded PS20. Additionally, a proteomics study was undertaken to identify the residual host cell proteins in the sulfatase drug substance.

DB-PABP: a database of polyanion-binding proteins.

The interactions between polyanions (PAs) and polyanion-binding proteins (PABPs) have been found to play significant roles in many essential biological processes including intracellular organization, transport and protein folding. Furthermore, many neurodegenerative disease-related proteins are PABPs. Thus, a better understanding of PA/PABP interactions may not only enhance our understandings of biological systems but also provide new clues to these deadly diseases.

A network-based analysis of polyanion-binding proteins utilizing human protein arrays.

The existence of interactions between many cellular proteins and various polyanionic surfaces within a cell is now well established. The functional role of such interactions, however, remains to be clearly defined. The existence of protein arrays, with a large selection of different kinds of proteins, provides a way to better address a number of aspects of this question.

A network-based analysis of polyanion-binding proteins utilizing yeast protein arrays.

The high affinity of certain cellular polyanions for many proteins (polyanion-binding proteins (PABPs)) has been demonstrated previously. It has been hypothesized that such polyanions may be involved in protein structure stabilization, stimulation of folding through chaperone-like activity, and intra- and extracellular protein transport as well as intracellular organization. The purpose of the proteomics studies reported here was to seek evidence for the idea that the nonspecific but high affinity interactions of PABPs with polyanions have a functional role in intracellular processes.

The use of mucoadhesive polymers in buccal drug delivery.

Buccal delivery of the desired drug using mucoadhesive polymers has been the subject of interest since the early 1980s. Advantages associated with buccal drug delivery have rendered this route of administration useful for a variety of drugs. This review highlights the use of mucoadhesive polymers in buccal drug delivery.

Current strategies used to enhance the paracellular transport of therapeutic polypeptides across the intestinal epithelium.

The intent of this paper is to update the reader on various strategies which have been utilized to increase the paracellular permeability of protein and polypeptide drugs across the intestinal epithelium. Structural features of protein and polypeptide drugs, together with the natural anatomical and physiological features of the gastrointestinal (GI) tract, have made oral delivery of this class of compounds extremely challenging. Interest in the paracellular route for the transport of therapeutic proteins and polypeptides following oral administration has recently intensified and continues to be explored.

A randomly coiled, high-molecular-weight polypeptide exhibits increased paracellular diffusion in vitro and in situ relative to the highly ordered alpha-helix conformer.

Purpose: The current investigation was conducted to examine the effect of secondary structure of model polypeptides on their hindered paracellular diffusion.

Methods: Poly-D-glutamic acid (PDGlu) was selected as one of the model polypeptides because of its ability to form two secondary structures; a negatively charged random coil and an alpha-helix with partial negative charge at pH 7.4 and 4.

An attempt to modulate the microporous diffusion of a model polypeptide by altering its secondary structure.

The purpose of the present study was to determine whether intentional alteration of the secondary structure of a model polypeptide, conantokin-G, influenced the rate and extent of aqueous pore diffusion across a synthetic microporous membrane. Use of a microporous synthetic membrane allowed for analysis of polypeptide transport without the confounding variables of protein binding, acid- and/or enzyme-mediated degradation, endocytotic uptake, and enzymatic inactivation associated with a biological membrane. Conantokin-G was intentionally changed from its native random coil structure to the alpha-helix structure using calcium, and both structures were verified using circular dichroism.

Poly(L-lysine) as a model drug macromolecule with which to investigate secondary structure and microporous membrane transport, part 2: diffusion studies.

Peptide drugs are hydrophilic in nature and so their preferred pathway of membrane transport is by the paracellular route, which primarily involves passive diffusion across intercellular pores. The objective of the present study was to investigate the effect of secondary structure on the aqueous diffusion of a model polypeptide, poly(L-lysine), through a microporous membrane. The primary aim was to systematically evaluate the variables (e.

Shape imposed by secondary structure of a polypeptide affects its free diffusion through liquid-filled pores.

The purpose of the present study was to investigate the effect of secondary structure of three model polypeptides on their apparent permeability (P(app)) across a synthetic, microporous membrane. Poly-L-lysine (PL), poly-L-glutamate (PGlu), and poly-L-lysine-L-phenylalanine (1:1) (PLP) were selected because a solution environment in which their predominant secondary structure is random coil (RC), alpha-helix, and beta-sheet, respectively, is easily achieved. The conformation of each polypeptide was verified by circular dichroism (CD).