Manufacturing Bacteriophages (Part 2 of 2): Formulation, Analytics and Quality Control Considerations

Abstract

Within this second piece of the two-part series of phage manufacturing considerations, we are examining the creation of a drug product from a drug substance in the form of formulation, through to fill-finish. Formulation of a drug product, in the case of bacteriophage products, is often considered only after many choices have been made in the development and manufacture of a drug substance, increasing the final product development timeline and difficulty of achieving necessary performance parameters. As with the preceding review in this sequence, we aim to provide the reader with a framework to be able to consider pharmaceutical development choices for the formulation of a bacteriophage-based drug product. The intent is to sensitize and highlight the tradeoffs that are necessary in the development of a finished drug product, and to be able to take the entire spectrum of tradeoffs into account, starting with early-stage R&D efforts. Furthermore, we are arming the reader with an overview of historical and current analytical methods with a special emphasis on most relevant and most widely available methods. Bacteriophages pose some challenges that are related to but also separate from eukaryotic viruses. Last, but not least, we close this two-part series by briefly discussing quality control (QC) aspects of a bacteriophage-based product, taking into consideration the opportunities and challenges that engineered bacteriophages uniquely present and offer.

Novel Stenotrophomonas maltophilia Bacteriophage as Potential Therapeutic Agent

“…CUB19 is stable to temperature and has a broad pH tolerance. Considering that a number of factors are known to impact phage structure and infectivity for the formulation of a drug product, among which temperature and pH are critical [ 37 ], having a stable phage can facilitate its production and processing. Isothermal microcalorimetry measurements provided real-time data on the interaction between increasing titers of CUB19 and the host strain, revealing a remarkable antibacterial effect even at the lowest MOI tested, with a prolonged lag time, indicative of a decrease in the number of viable bacteria compared to the untreated sample.…”

Practical Assessment of an Interdisciplinary Bacteriophage Delivery Pipeline for Personalized Therapy of Gram-Negative Bacterial Infections

“…The removal can be achieved with laboratory methods such as dialysis [12,34]. A loss of titre of the phage can be countered with a preceding large-scale titration [57].…”

“…(4) Little is known about the appropriate phage formulation to be used [54,58,[63][64][65][66]. Therefore, pharmacological experts or phage experts, trained in pharmacological properties, decide on the best approach (for fluids usually 0.9% NaCl, which is not suitable for all phages), best pH-value (adapted to the phage and route of administration), and suitable pH-stabilizing buffer (e.g., citrate or trometamol) [57,58]. The homogeneity of the solution is examined [11].…”

“…The homogeneity of the solution is examined [11]. Carriers, such as ointments and hydrogels, and encapsulations, such as alginate polymers, can be useful for various routes of administration [57,58].…”

Tracking the phage trends: A comprehensive review of applications in therapy and food production

“…For the intravenous route of administration, phages may be delivered through injection and infusion. Quality control (QC) for the release of phage products includes assessment of phage identity, purity, and safety for checking that the final product is free of any impurities, followed by testing phage viability to check the loss of titer during product preparation and formulation ( Moraes de Souza et al, 2021 ).…”