Development

The transdermal delivery of biologics-as well as of conventional drugs-is growing in popularity because the technique offers numerous advantages.

The type of reactive moiety controls the site and stability of the covalent link and also the total number of PEGylation sites on a given protein.

Extra column effects must be accounted for to make a valid comparison

Over the last three decades, numerous protein expression systems have been developed with various quality requirements on large and small scales. Huge steps have been made in large-scale protein production in mammalian systems while the small-scale mammalian systems are expensive and inflexible. Thus, small-scale production is done in simpler expression systems, sometimes sacrificing the quality of the proteins. However, relief is on the way.

Yeast systems have been a staple for producing large amounts of proteins for industrial and biopharmaceutical use for many years. Yeast can be grown to very high cell mass densities in well-defined medium. Recombinant proteins in yeast can be over-expressed so the product is secreted from the cell and available for recovery in the fermentation solution. Proteins secreted by yeasts are heavily glycosylated at consensus glycosylation sites. Thus, expression of recombinant proteins in yeast systems historically has been confined to proteins where post-translations glycosylation patterns do not affect the function of proteins. Several yeast expression systems are used for recombinant protein expression, including Sacharomyces, Scizosacchromyces pombe, Pichia pastoris and Hansanuela polymorpha.

Managing codon pair interactions and simultaneously optimizing the entire set of parameters requires advanced computationally intensive design tools.

Rapid, efficient, and cost-effective protein expression and purification strategies are required for high throughput structural genomics and the production of therapeutic proteins. Fusion protein technology represents one strategy to achieve these goals. Fusion protein technology can facilitate purification, enhance protein expression and solubility, chaperone proper folding, reduce protein degradation, and in some cases, generate protein with a native N-terminus. No technology or reagent is a panacea, however, and establishing tools and optimal conditions for each protein remains an empirical exercise. With this in mind, protein fusions are a leading option to produce difficult-to-express proteins, especially in Escherichia coli.

The speed at which a recombinant protein product progresses into clinical trials is of vital importance for both small biotechnology companies as well as the biopharma groups of large pharmaceutical companies. For mammalian cell lines, two major impacts on the project timeline are the ability to quickly identify a product candidate and subsequently produce a high-expressing cell line for that product. The advent of various computer-based protein design methodologies and antibody discovery technologies for developing protein therapeutics has resulted in large numbers of protein or antibody variants that must be screened to identify the best clinical candidate.

Development guidelines for MAbs serve as a blueprint for their manufacture, safety, and efficacy testing.

Before designing cleaning procedures, it's vital to know all physical and chemical characteristics of the product ingredients.

Cleaning validation is a critical consideration in the pharmaceutical industry. Inadequate cleaning can result in contamination of drug products with bacteria, endotoxins, active pharmaceuticals from previous batch runs, and cleaning solution residues. Such contaminants must be reduced to safe levels, both for regulatory approval and to ensure patient safety.

The cell density achieved in a CELLine bioreactor is typically 1 to 2 orders of magnitude higher than in a conventional culture vessel

Many industry professionals know that analytical testing for biopharmaceuticals for all raw materials, production in-process stages, and final containers must be validated, and they generally understand how this can be achieved. Many of us even understand the basic concepts of laboratory compliance and production process quality. However, how exactly are analytical test method performance and process robustness related and how do they depend on each other? Furthermore, how do we monitor and maintain the accuracy and reliability of analytical methods long after validation completion to ensure the suitability of these methods for measuring process quality?

Cell-line and process development expertise, along with disposable systems, assist in implementing strategies for fast expression enhancements.

Saturated fractional factorial plans minimize the number of trials by one-half or better, which saves time and money.

Creation and qualification of scale-down models is essential for performing several critical activities that support process validation and commercial manufacturing. This combined article is the fifth in the "Elements of Biopharmaceutical Production" series. Part 1 (March 2005) covered fermentation. In this segment, we present some guidelines and examples for scale-down of common downstream unit operations used in biotech processes - chromatography and filtration.

Synthetic drugs can be well characterized by established analytical methods. Biologics on the other hand are complex, high-molecular-weight products, and analytical methods have limited abilities to completely characterize them and their impurity profiles. Regulation of biologics includes not only final product characterization but also characterization and controls on raw materials and the manufacturing process.

Many types of equipment in both manufacturing and laboratory areas are critical to a properly functioning pharmaceutical process. The validation of laboratory equipment is not as clearly defined as the validation of equipment used directly in the production of pharmaceutical products, which requires thorough validation in almost all situations.

Lot-to-lot variations between raw materials can greatly impact process performance.

The purpose of design validation is to demonstrate that a product performs as intended. The usual route to this goal is showing that every item on the specification has been achieved, but it is not an easy path. The specification itself can create difficulty if it includes statements like "as long as possible" or the real horror "to be decided." Verification tests can reveal so many problems that the design must change to such an extent that earlier tests are no longer relevant. And there is also the practical difficulty of obtaining sufficient samples to test when the manufacturing engineers have not completed their standard operating procedures, the product design is not fixed yet, the component suppliers are late, and the marketing department has taken all the samples to show to prospective customers.

In order to institute a GxP mindset across the organization, support and respect for quality systems should come from the top down.

When replacing an existing method, it may be necessary to compensate for a significant difference between the current and new method by adjusting the specifications.

The relationship between "valid" or "suitable and validated" is often overlooked, but there is a high price when "validated" test systems are simply inappropriate.

Filtration is one of the most commonly used unit operations in the manufacturing of biopharmaceuticals. This is the second part of the fourth article in the "Elements of Biopharmaceutical Production" series. In this second segment, Manoj Menon and Frank Riske present an approach for the development and optimization of a TFF application, followed by a contribution from Jennifer Campbell and Elizabeth Goodrich reviewing key issues involved in validation of a TFF step.

Filtration is one of the most commonly used unit operations in biopharmaceutical manufacturing. Available formats include direct or normal flow filtration (NFF) and cross or tangential flow filtration (TFF). These methods are used for sterilization and virus filtration, depth filtration or ultrafiltration, and diafiltration applications. Some common objectives include:

Networks are part of the compliance picture. Recent FDA warning letters show the agency considers network monitoring and qualification a necessary part of maintaining the security and integrity of electronic records.

Biotech companies are among the most intensive instrumentation users of any FDA-regulated business. Because of the complex nature of these companies' research and manufacturing, they typically have a larger number of instruments per employee.

Although gene therapy and DNA vaccination suggest promising new approaches to disease treatment - and nonviral vectors (which are cheap and easy to manufacture) afford low immunogenicity, better safety profiles, and improved stability - commercial-scale purification of plasmid DNA remains difficult, particularly if bovine-derived ribonuclease A is left out of the process. This article series reviews the benefits and limitations of current plasmid DNA purification and suggests an RNase-free downstream process that is scalable, robust, and meets the requirements set by industry regulators.