A new roadmap for biopharmaceutical drug product development: Integrating development, validation, and quality by design.

Quality by design (QbD) is a science- and risk-based approach to drug product development. Although pharmaceutical companies have historically used many of the same principles during development, this knowledge was not always formally captured or proactively submitted to regulators. In recent years, the US Food and Drug Administration has also recognized the need for more controls in the drug manufacturing processes, especially for biological therapeutics, and it has recently launched an initiative for Pharmaceutical Quality for the 21st Century to modernize pharmaceutical manufacturing and improve product quality. In the biopharmaceutical world, the QbD efforts have been mainly focused on active pharmaceutical ingredient processes with little emphasis on drug product development. We present a systematic approach to biopharmaceutical drug product development using a monoclonal antibody as an example. The approach presented herein leverages scientific understanding of products and processes, risk assessments, and rational experimental design to deliver processes that are consistent with QbD philosophy without excessive incremental effort. Data generated using these approaches will not only strengthen data packages to support specifications and manufacturing ranges but hopefully simplify implementation of postapproval changes. We anticipate that this approach will positively impact cost for companies, regulatory agencies, and patients, alike.

Stabilization of a polypeptide in non-aqueous solvents.

A pituitary adenylate cyclase-activating peptide (PACAP) analogue (HSDAVFTDNYTRLRKQVAAKKYLQSIKNKRY, P66) was formulated in several non-aqueous solvents in anticipation of improved shelf-life stability. However, the stability of this peptide in these solvents was found to be as poor as in an aqueous solution. The major degradation reaction in non-aqueous solvents was dimer formation. The proposed mechanism for dimerization was a nucleophilic attack of a basic amino acid on cyclic imide formed by dehydration or deamidation of Asp or Asn. Two approaches were found to be effective in stabilizing the peptide in non-aqueous solvents: (1) acidification of the peptide and (2) use of zinc chloride in the formulation. Stabilization could be attributed to reduction of the nucleophilicity of the reactive groups through protonation and metal-peptide interaction through chelation. The stabilization approaches are applicable only in a non-aqueous environment for this peptide, and possibly for other peptides with similar reactive moieties.

Oxidation of protein by vaporized sanitizing agents.

For the first time, it has been demonstrated that a protein product can be oxidized readily by certain sanitizing agents through vapor transfer not only in a closed system but also in an open environment. The effect of several sanitizing agents on the oxidation of a model protein, IL-2 mutein, was investigated under different processing conditions. Reversed phase-high performance liquid chromatography (RP-HPLC) was used to separate and quantitate both intact and oxidized IL-2 mutein. It was found that peracetic acid or NaOCl oxidizes IL-2 mutein instantaneously, while H2O2-induced oxidation of IL-2 mutein is much slower in solution. The amount of protein oxidation product is proportional to the duration of sample exposure and the type and concentration of the sanitizing agent. In addition, sanitizing agents can accelerate protein oxidation during lyophilization, and the residual amount can promote oxidation of the lyophilized product during storage. These results strongly suggest that the sanitization process needs to be properly controlled and closely monitored during manufacturing of drug products that are sensitive to oxidation.