Subcutaneous Delivery of High-Dose/Volume Biologics: Current Status and Prospect for Future Advancements

Formulation Factors Affecting the Formation of Visible-Bubbles During the Reconstitution Process of Freeze-Dried Etanercept Formulations: Protein Concentration, Stabilizers, and Surfactants

Freeze drying is one of the common methods to extend the long-term stability of biologicals. Biological products in solid form have the advantages of convenient transportation and stable long-term storage. However, long reconstitution time and extensive visible bubbles are frequently generated during the reconstitution process for many freeze-dried protein formulations, which can potentially affect the management efficiency of staff, patient compliance, and product quality. The reconstitution time has been extensively studied, but the influence of the formulations on the formation of visible bubbles is often overlooked. This paper investigated the effect of freeze-drying formulation factors (i.e., protein concentrations, surfactant concentrations, and sucrose/mannitol compositions) on product stability and visible bubbles generated during reconstitution of freeze-dried etanercept formulations. The generating and breakup mechanisms of visible bubbles were detected via internal microstructure of cake, surface tension, and viscosity measurement. Under the same protein concentration, the formulation of mannitol mixed with sucrose in a weight ratio of 4:1 produces fewer visible bubbles during the reconstitution process compared to the formulation of sucrose with the same total mass. This has been proven to be due to the large number of smaller radius pores distributed in the pores of the freeze-dried cake of the former, while the average internal structure pores of the latter are much larger than those of the former. As an amorphous stabilizer, sucrose can ensure the long-term stability of protein and greatly reduce the generation and maintenance of foams in the reconstitution process, making it a more robust excipient for freeze-dried protein formulations.

Novel strategies in systemic and local administration of therapeutic monoclonal antibodies

Monoclonal antibodies (mAbs) are an evolving class of biopharmaceuticals, with advancements evident across various stages of their development. While discovery, mAb chemical optimization, production and purification processes have been thoroughly reviewed, this paper aims to offer a summary of novel strategies in administration of mAbs. At present, systemic delivery of mAbs is available through parenteral administration routes with focus on subcutaneous administration. In addition, oriented toward patient-friendly therapy, other less invasive administration routes of mAbs, such as inhalation, nasal, transdermal, and oral administration, are explored. Literature data reveals the potential for local delivery of mAbs via inhalation, nasal, transdermal, intratumoral, intravitreal and vaginal administration, offering high efficacy with fewer systemic adverse effects. However, to date, only mAb medicines are available for intravitreal administration, mainly due to higher bioavailability, and an intranasal spray is authorised as a medical device. The review highlights the promising data in approval of novel administration routes, likely through inhalation, but further intensive research considering the current obstacles, is essential.

Jet injection through microneedles for large volume subcutaneous delivery

Subcutaneous (SC) drug delivery offers several advantages over intravenous (IV) delivery including: self-administration, improved patient experience, and reduced treatment costs. Unfortunately, each SC delivery is currently limited to ∼ 2.25 mL with IV administration required when the delivery volume exceeds this value. In this work, we explore a new technique for large volume subcutaneous drug delivery that uses microneedles to break through the epidermis then forms the liquid drug into many small jets that penetrate past the ends of the microneedles and into the subcutaneous (or muscle) tissue. By performing multiple simultaneous injections, this delivery approach avoids the volume limitations of SC delivery, and thus may be able to greatly increase the volume we can deliver to this space. Here, we present a novel multi-jet prototype that forms seven simultaneous jets through 30G needles that have been shortened to have an exposed length of just ∼ 1mm. The jet speed, shape, and volume of jets formed through these microneedles are measured to assess the consistency of jet production through the microneedles. We then perform jet injections of volumes up to 3.9 mL into ex vivo porcine tissue. The results demonstrate the successful delivery (>95 %) of 3.9 mL in just 0.3 s using jet injection performed through microneedles. This volume is almost double the maximum volume of current autoinjectors and the perceived limit for subcutaneous injection (2.25 mL). We also find that jet speeds of 70 m/s and below do not achieve complete delivery of 3.9 mL with our prototype system, and that the addition of microneedles leads to more consistent large volume delivery than equivalent needle-free injections. These results demonstrate the promise of multi-jet injection through microneedles to accommodate volumes much greater than current autoinjectors, and thus potentially allow patient self-administration in many more delivery applications.

Customizing subcutaneous immunoglobulin administration in primary antibody deficiency: patient-centric care perspectives

This report delves into the challenges and potential solutions associated with flexible, customized subcutaneous immunoglobulin (SCIG) infusion regimens for patients with primary antibody deficiency disease (PAD). Advances in the treatment of inborn errors of immunity, particularly PAD, have converted fatal diseases into chronic, complex, long-term conditions that make adherence to treatment a critical issue. Conventional SCIG infusion regimens, while clinically effective, may not always align with the varied lifestyles, changing lifestyles and commitments of patients which can lead to missed doses, diminishing adherence thus posing potential health risks and compromising the overall effectiveness of treatment. For these reasons, it's important to develop flexible infusion regimens tailored to meet individual patient needs. Patient-centric strategies that promote shared decision-making and awareness of patient status not only promote medical efficacy but also enhance the overall patient experience. The authors of this report call attention for a need to shift toward more adaptable and individualized SCIG treatment plans for PAD patients whose needs may change over the long-term course of treatment.

The effect of temperature-dependent drug viscosity on needle-free jet injection

Highly viscous drugs cannot be delivered through a needle. Typically, this means that these drugs are formulated at lower concentrations, demanding higher delivery volumes, which often must be delivered intravenously. Jet injection may provide an important solution for viscous drug delivery. Jet injection is a needle-free drug delivery technique whereby a liquid drug is formed into a hair-thin (∼200 µm) high-speed (>100 m/s) jet that penetrates and delivers itself into tissue. While it may seem that it would be just as difficult to form a viscous drug into a high-speed jet as it is to force it down a needle, this is not the case. Recent work has revealed that 'viscous-heating' during jet injection can result in significant temperature increase, and resultant viscosity decrease, in a thin outer-layer of the jet; this phenomenon effectively results in the drug 'self-lubricating' as it passes through a jet injection orifice. Despite the potential for this finding to revolutionise the subcutaneous delivery of high-viscosity drugs, little further work in this area has since been reported on. In this work we develop finite element models of needle-free injection to investigate how viscous heating affects jet production, how heat exchange with the orifice material influences this process, and to what extent jet production is affected by the initial temperature of the fluid. We then conduct novel high-speed measurements of jet and orifice temperature changes due to viscous heating. We find that viscous heating is responsible for approximately doubling the speed of jets that can be produced with very viscous fluid (1 Pa·s) at room temperature. The thermal conductivity of the orifice can transfer heat away from the perimeter of the jet, and thus reduce the lubricating effect of viscous heating. We then show that by preheating 99 % glycerol (1 Pa·s) from 7 °C to 37 °C the jet speed can be increased 6-fold. We also demonstrate the successful delivery of a very viscous glycerol solution using preheated jet injection into ex vivo porcine tissue. Given that 99 % glycerol is 10- to 100-fold more viscous than current protein therapeutics, our findings demonstrate the potential for jet injection, with or without additional drug preheating, to deliver drug formulations, needle-free, that are much more viscous than those currently delivered through needles.

Investigation into the Acceptability of Moderate-to-Large Volume Subcutaneous Injections in Healthy Volunteers: Results from a Single-Center Randomized Controlled Study

Purpose

Therapeutic proteins are often delivered by subcutaneous (SC) autoinjector to enable self-administration. Autoinjectors typically deliver up to 1 mL injected volumes per dose. Delivery of larger volumes may be limited by injection site discomfort, including pain, swelling, and redness. Delivery at a slower rate may mitigate this discomfort. This single-center, randomized, crossover study evaluated the acceptability and tolerability of varying volumes and delivery rates of SC saline in healthy volunteers.

Patients and Methods

Eligible participants were adults (18-65 years) with a body mass index of 18.5-32.0 kg/m2. Participants (N = 24) were randomized to multiple sequences of infusions over five visits, with infusions ranging from 1 to 5 mL at rates of 1.50-6.00 mL/minute (min) and including a 1 mL SC infusion in 10 seconds (s) at a rate of 6.00 mL/min. The primary objective was to identify acceptable volume and delivery rates of SC saline, as assessed by visual analogue scale (VAS) pain scores, a tolerability and acceptability questionnaire, and infusion leakage.

Results

Infusions that met the acceptability criteria were 1 mL in 10s, 4 mL in 58s, and 3 mL in 2 mins. Higher delivery volumes and rates were associated with higher VAS pain scores but remained within the VAS acceptability criteria.

Conclusion

These findings may support the development of larger-volume injectors for self-administration of future medicines.

Stability of Protein Pharmaceuticals: Recent Advances

There have been significant advances in the formulation and stabilization of proteins in the liquid state over the past years since our previous review. Our mechanistic understanding of protein-excipient interactions has increased, allowing one to develop formulations in a more rational fashion. The field has moved towards more complex and challenging formulations, such as high concentration formulations to allow for subcutaneous administration and co-formulation. While much of the published work has focused on mAbs, the principles appear to apply to any therapeutic protein, although mAbs clearly have some distinctive features. In this review, we first discuss chemical degradation reactions. This is followed by a section on physical instability issues. Then, more specific topics are addressed: instability induced by interactions with interfaces, predictive methods for physical stability and interplay between chemical and physical instability. The final parts are devoted to discussions how all the above impacts (co-)formulation strategies, in particular for high protein concentration solutions.'

Broadly neutralizing antibodies for HIV prevention: a comprehensive review and future perspectives

SUMMARYThe human immunodeficiency virus (HIV) epidemic remains a formidable global health concern, with 39 million people living with the virus and 1.3 million new infections reported in 2022. Despite anti-retroviral therapy's effectiveness in pre-exposure prophylaxis, its global adoption is limited. Broadly neutralizing antibodies (bNAbs) offer an alternative strategy for HIV prevention through passive immunization. Historically, passive immunization has been efficacious in the treatment of various diseases ranging from oncology to infectious diseases. Early clinical trials suggest bNAbs are safe, tolerable, and capable of reducing HIV RNA levels. Although challenges such as bNAb resistance have been noted in phase I trials, ongoing research aims to assess the additive or synergistic benefits of combining multiple bNAbs. Researchers are exploring bispecific and trispecific antibodies, and fragment crystallizable region modifications to augment antibody efficacy and half-life. Moreover, the potential of other antibody isotypes like IgG3 and IgA is under investigation. While promising, the application of bNAbs faces economic and logistical barriers. High manufacturing costs, particularly in resource-limited settings, and logistical challenges like cold-chain requirements pose obstacles. Preliminary studies suggest cost-effectiveness, although this is contingent on various factors like efficacy and distribution. Technological advancements and strategic partnerships may mitigate some challenges, but issues like molecular aggregation remain. The World Health Organization has provided preferred product characteristics for bNAbs, focusing on optimizing their efficacy, safety, and accessibility. The integration of bNAbs in HIV prophylaxis necessitates a multi-faceted approach, considering economic, logistical, and scientific variables. This review comprehensively covers the historical context, current advancements, and future avenues of bNAbs in HIV prevention.

Towards more tolerable subcutaneous administration: Review of contributing factors for improving combination product design

Subcutaneous (SC) injections can be associated with local pain and discomfort that is subjective and may affect treatment adherence and overall patient experience. With innovations increasingly focused on finding ways to deliver higher doses and volumes (≥2 mL), there is a need to better understand the multiple intertwined factors that influence pain upon SC injection. As a priority for the SC Drug Development & Delivery Consortium, this manuscript provides a comprehensive review of known attributes from published literature that contribute to pain/discomfort upon SC injection from three perspectives: (1) device and delivery factors that cause physical pain, (2) formulation factors that trigger pain responses, and (3) human factors impacting pain perception. Leveraging the Consortium's collective expertise, we provide an assessment of the comparative and interdependent factors likely to impact SC injection pain. In addition, we offer expert insights and future perspectives to fill identified gaps in knowledge to help advance the development of patient-centric and well tolerated high-dose/high-volume SC drug delivery solutions.

Pharmaceutical and biotech industry perspectives on optimizing patient experience and treatment adherence through subcutaneous drug delivery design

Subcutaneous (SC) drug delivery can be a safe, effective alternative to the traditional intravenous route of administration, potentially offering notable advantages for both patients and healthcare providers. The SC Drug Development & Delivery Consortium convened in 2018 to raise awareness of industry challenges to advance the development of patient-centric SC drug delivery strategies. The SC Consortium identified better understanding of patient preferences and perspectives as necessary to optimize SC product design attributes and help guide design decisions during SC product development. This manuscript provides a comprehensive overview of patient-centric factors for consideration in the SC drug delivery design and development process with the aim of establishing a foundation of existing knowledge for patient experiences related to SC drug delivery. This overview is informed by the outcomes of a multi-step survey of Consortium members and key pharmaceutical stakeholders. Framed in the context of the patient's treatment journey, the survey findings offer future perspectives to fill data gaps to advance patient-centric SC drug delivery.

Sequence-Based Viscosity Prediction for Rapid Antibody Engineering

Through machine learning, identifying correlations between amino acid sequences of antibodies and their observed characteristics, we developed an internal viscosity prediction model to empower the rapid engineering of therapeutic antibody candidates. For a highly viscous anti-IL-13 monoclonal antibody, we used a structure-based rational design strategy to generate a list of variants that were hypothesized to mitigate viscosity. Our viscosity prediction tool was then used as a screen to cull virtually engineered variants with a probability of high viscosity while advancing those with a probability of low viscosity to production and testing. By combining the rational design engineering strategy with the in silico viscosity prediction screening step, we were able to efficiently improve the highly viscous anti-IL-13 candidate, successfully decreasing the viscosity at 150 mg/mL from 34 cP to 13 cP in a panel of 16 variants.

Evaluating unmet needs in large-volume subcutaneous drug delivery: U.S. payer perspectives on a novel, large-volume on-body delivery system

OBJECTIVE

Existing healthcare systems face finite resource allocation and budgetary constraints, resulting in a substantial need for innovative solutions to enhance service delivery at reduced costs. A novel, user-friendly on-body delivery system (OBDS) was developed which enables administration of large-volume subcutaneous (SC) drugs in both clinical and home-based settings (at-home healthcare professional [HCP] administration or at-home self-administration).

METHODS

This research sought to evaluate the potential economic impact of at-home self- or HCP- administration with the OBDS through a comprehensive review of published literature and semi-structured interviews with 17 US payers representing approximately 227 million covered lives.

RESULTS

Published literature on OBDS remains limited, but available research highlights the cost-savings of SC administration due to reduced healthcare resource utilization, particularly with home-based care, and improved patient compliance. In interviews, payers identified several attributes that would help address unmet clinical and economic needs. Clinically, the hidden needle and ease-of-use compared to SC syringe pumps was deemed valuable to improve patient compliance and, as OBDS required minimal training, reduce the risk of administration errors. The flexibility to administer drugs at home (self-administration or HCP-administration) or in-clinic was identified as the most impactful attribute on coverage decision making as it has the greatest potential to reduce costs associated with HCP administration for several therapeutic areas.

CONCLUSIONS

Given the ability to help address critical unmet needs for the patient and healthcare system, a large proportion of the payers stated that the novel OBDS would warrant a price premium versus the cost of the standalone SC vial and certainly over the IV counterpart. Future research to quantify the value that OBDS efficiencies could bring to healthcare delivery are warranted.

Design of a Reciprocal Injection Device for Stability Studies of Parenteral Biological Drug Products

Formulation screening, essential for assessing the impact of physical, chemical, and mechanical stresses on protein stability, plays a critical role in biologics drug product development. This research introduces a Reciprocal Injection Device (RID) designed to accelerate formulation screening by probing protein stability under intensified stress conditions within prefilled syringes. This versatile device is designed to accommodate a broad spectrum of injection parameters and diverse syringe dimensions. A commercial drug product was employed as a model monoclonal antibody formulation. Our findings effectively highlight the efficacy of the RID in assessing concentration-dependent protein stability. This device exhibits significant potential to amplify the influences of interfacial interactions, such as those with buffer salts, excipients, air, metals, and silicone oils, commonly found in combination drug products, and to evaluate the protein stability under varied stresses.

A Comprehensive Analysis of Biopharmaceutical Products Listed in the FDA's Purple Book

Although biopharmaceuticals constitute around 10% of the drug landscape, eight of the ten top-selling products were biopharmaceuticals in 2023. This study did a comprehensive analysis of the FDA's Purple Book database. Firstly, our research uncovered market trends and provided insights into biologics distributions. According to the investigation, although biotechnology has advanced and legislative shifts have made the approval process faster, there are still challenges to overcome, such as molecular instability and formulation design. Moreover, our research comprehensively analyzed biological formulations, pointing out significant strategies regarding administration routes, dosage forms, product packaging, and excipients. In conjunction with biologics, the widespread integration of innovative delivery strategies will be implemented to confront the evolving challenges in healthcare and meet an expanding array of treatment needs.

A Review of Recent FDA-Approved Biologic-Device Combination Products

With the remarkably strong growth of the biopharmaceutical market, an increasing demand for self-administration and rising competitions attract substantial interest to the biologic-device combination products. The ease-of-use of biologic-device combination products can minimize dosing error, improve patient compliance and add value to the life-cycle management of biological products. As listed in the purple book issued by the U.S. Food and Drug Administration (FDA), a total of 98 brand biologic-device combination products have been approved with Biologic License Application from January 2000 to August 2023, where this review mainly focused on 63 products containing neither insulin nor vaccine. Prefilled syringes (PFS) and autoinjectors are the most widely adopted devices, whereas innovative modifications like needle safety guard and dual-chamber design and novel devices like on-body injector also emerged as promising presentations. All 16 insulin products employ pen injectors, while all 19 vaccine products are delivered by a PFS. This review provides a systematic summary of FDA-approved biologic-device combination products regarding their device configurations, routes of administration, formulations, instructions for use, etc. In addition, challenges and opportunities associated with biologic-device compatibility, regulatory complexity, and smart connected devices are also discussed. It is believed that evolving technologies will definitely move the boundaries of biologic-device combination product development even further.

Clinical Investigation of Large Volume Subcutaneous Delivery up to 25 mL for Lean and Non-Lean Subjects

PURPOSE

To evaluate the clinical feasibility and tolerability of large volume subcutaneous delivery at different injection depths for lean and non-lean subjects.

METHODS

A single-center, randomized, subject-blinded, crossover study in 62 healthy subjects was conducted to evaluate delivery of a 10-cP solution containing hyaluronic acid. Subjects were separated into lean and non-lean cohort by SC thickness. A syringe pump was used to study the effect of different volumes (5, 12, 25 mL) of a viscous placebo solution and needle lengths (6, 9 and 12 mm) delivered at 0.5 mL/min.

RESULTS

Across all treatments, injection sites were observed to have negligible leakage, ~34 kPa of back pressure, and VAS of mild pain with higher pain from needle insertion than during injection. While mild to moderate erythema was the most frequently reported ISR and edema was most prominent for 25 mL injections, all ISRs were resolved within 4 hours post injection. Subjects were unbothered by ISRs across all treatments and rated them as low distress scores (average 1.0-1.5 out of 6).

CONCLUSION

SC injection of 25 mL is feasible and tolerable using a low-pain formulation for abdomen injection irrespective of subcutaneous thickness and injection depths at a delivery rate of 0.5 mL/min.

Subcutaneous Administration of Monoclonal Antibodies: Pharmacology, Delivery, Immunogenicity, and Learnings From Applications to Clinical Development

Subcutaneous (s.c.) administration of monoclonal antibodies (mAbs) can reduce treatment burden for patients and healthcare systems compared with intravenous (i.v.) infusion through shorter administration times, made possible by convenient, patient-centric devices. A deeper understanding of clinical pharmacology principles related to efficacy and safety of s.c.-administered mAbs over the past decade has streamlined s.c. product development. This review presents learnings from key constituents of the s.c. mAb development pathway, including pharmacology, administration variables, immunogenicity, and delivery devices. Restricted mAb transportation through the hypodermis explains their incomplete absorption at a relatively slow rate (pharmacokinetic (PK)) and may impact mAb-cellular interactions and/or onset and magnitude of physiological responses (pharmacodynamic). Injection volumes, formulation, rate and site of injection, and needle attributes may affect PKs and the occurrence/severity of adverse events like injection-site reactions or pain, with important consequences for treatment adherence. A review of immunogenicity data for numerous compounds reveals that incidence of anti-drug antibodies (ADAs) is generally comparable across i.v. and s.c. routes, and complementary factors including response magnitude (ADA titer), persistence over time, and neutralizing antibody presence are needed to assess clinical impact. Finally, four case studies showcase how s.c. biologics have been clinically developed: (i) by implementation of i.v./s.c. bridging strategies to streamline PD-1/PD-L1 inhibitor development, (ii) through co-development with i.v. presentations for anti-severe acute respiratory syndrome-coronavirus 2 antibodies to support rapid deployment of both formulations, (iii) as the lead route for bispecific T cell engagers (BTCEs) to mitigate BTCE-mediated cytokine release syndrome, and (iv) for pediatric patients in the case of dupilumab.

Microfluidic Delivery of High Viscosity Liquids Using Piezoelectric Micropumps for Subcutaneous Drug Infusion Applications

Goal: Auto-injectors for self-administration of drugs are usually refrigerated. If not warmed up prior to the injection, ejection of the total drug volume is not guaranteed, as their spring and plunger mechanism cannot adjust for a change in viscosity of the drug. Here, we develop piezoelectric micro diaphragm pump that allows these modifications possible while investigating the effectiveness of this alternative dosing method. Methods: The dosing of highly viscous liquid of 25 mPa·s is made possible using application-specific micropump design. By comparing the analytical with experimental results, the practicality of the concept is verified. Results: Using a powerful piezoelectric stack actuator, the micropump achieves high fluid pressures of up to (368 ± 17) kPa. In order to assess the influence of viscosity, we characterize the fluidic performance of the designed micropump through 27G gauge needle for various water-glycerin mixtures. We find maximum flow rates of 2 mL/min for viscosities of up to 25 mPa·s. Conclusions: The developed micro diaphragm pump enables the development of smart auto-injectors with flow rate regulation to achieve drug delivery for high viscosity drugs through 27G needles.

Large volume subcutaneous delivery using multi-orifice jet injection

Needle-free jet injection is an alternative drug delivery technique that uses the liquid drug itself to penetrate through the skin. This technology is not only a promising alternative to hypodermic needles but also has the potential to replace intravenous delivery with rapid, needle-free subcutaneous delivery for large-volume treatments. In this work we propose a parallelised, 'multi-orifice' approach to overcome the volume constraints of subcutaneous tissue. We present a prototype multi-orifice nozzle with up to seven orifices and use this nozzle to perform injections into samples of ex vivo porcine tissue. These injections demonstrated the rapid (<0.15 s) delivery of up to 2 mL into the tissue using both three and seven orifices. Delivery success (measured as the percentage of fluid deposited in the tissue relative to the total volume that left the device) was very similar when using three versus seven injection orifices. A computational fluid dynamic model of multi-orifice jet injection is also presented. This model predicts that jet production is largely unaffected as the spacing between orifices is changed from 3 mm to 48 mm. This finding is supported by measurements of the speed, volume, and shape of the jets produced by the prototype nozzle that showed very similar jets were produced through all seven orifices. These findings demonstrate the feasibility of multi-orifice jet injection for needle-free delivery of large volumes. This promising technique has the potential to improve patient experience and reduce healthcare costs in large volume parenteral delivery applications.

Multiple approaches to reduce reconstitution time of lyophilized drug products with high protein concentration

Background

Lyophilized drug products with high protein concentration often perform long reconstitution time, which is inconvenient for clinical use. The objective of this work is to achieve short reconstitution time with multiple and combined strategies.

Methods

Here, we describe the following approaches that lead to reduction of reconstitution time, including adding annealing step, decreasing headspace pressure, decreasing protein concentration with reducing diluent volume, increasing high surface-area-to-height ratio of the cakes, increasing frequency of swirling and diluent temperature.

Results

Among these strategies, reducing diluent volume to achieve high protein concentration and reducing headspace pressure show markedly reduction of reconstitution time. Moreover, we propose combined strategies to mitigate the reconstitution time, at the same time, to achieve same target dose in clinics.

Conclusions

Therefore, this paper provides insights on the application of multiple strategies to accelerate the reconstitution of lyophilized drug products with high concentration, and facilitates their widespread clinical application.

Navigating large-volume subcutaneous injections of biopharmaceuticals: a systematic review of clinical pipelines and approved products

Subcutaneous (SC) administration is transforming the delivery of biopharmaceuticals, facilitating care in a variety of healthcare settings, including home self-treatment. Large-volume single SC doses have gained attention for their potential to expand therapeutic applications and improve long-term, patient-centric dosing regimens, often at a reduced SC injection frequency. However, a systematic understanding of dose volumes and frequencies for large-volume (>2.0 mL) SC biopharmaceuticals (LVSCs) is lacking. Accordingly, this study systematically reviewed clinical-stage and approved intravenous (IV) and SC biopharmaceuticals, identifying 182 LVSCs - predominantly monoclonal or bispecific antibodies - which correspond to approximately 15% of all IV and SC biopharmaceuticals. These LVSCs are designed to target cancer and a range of non-cancer chronic disease states, including autoimmune, neurological, and cardiovascular diseases. Results show that anti-cancer LVSCs (n = 75) typically require 5.0 to 20.0 mL doses every three weeks and are administered by healthcare professionals. In contrast, non-cancer LVSCs (n = 107), which are typically self-administered monthly, show more significant dosing variability, with < 5.0 mL being the predominant volume range. Furthermore, the study identified a substantial clinical pipeline of potential LVSCs, many of which are being injected at increasingly lower dosing frequencies, suggesting significant future growth in this area. Most non-cancer LVSCs are currently undergoing clinical trials via the SC route, whereas the majority of the cancer LVSCs are being administered IV and require transition to the SC route. These findings highlight the importance of developing large-volume drug delivery systems and novel formulations to reduce injection volumes. The analysis provides valuable guidance for new product development, as well as for marketing and commercialization strategies in the rapidly evolving LVSC landscape.

In-situ biophysical characterization of high-concentration protein formulations using wNMR

High-concentration protein formulation is of paramount importance in patient-centric drug product development, but it also presents challenges due to the potential for enhanced aggregation and increased viscosity. The analysis of critical quality attributes often necessitates the transfer of samples from their primary containers together with sample dilution. Therefore, there is a demand for noninvasive, in situ biophysical methods to assess protein drug products directly in primary sterile containers, such as prefilled syringes, without dilution. In this study, we introduce a novel application of water proton nuclear magnetic resonance (wNMR) to evaluate the aggregation propensity of a high-concentration drug product, Dupixent® (dupilumab), under stress conditions. wNMR results demonstrate a concentration-dependent, reversible association of dupilumab in the commercial formulation, as well as irreversible aggregation when exposed to accelerated thermal stress, but gradually reversible aggregation when exposed to freeze and thaw cycles. Importantly, these results show a strong correlation with data obtained from established biophysical analytical tools widely used in the pharmaceutical industry. The application of wNMR represents a promising approach for in situ noninvasive analysis of high-concentration protein formulations directly in their primary containers, providing valuable insights for drug development and quality assessment.

Reversible protein complexes as a promising avenue for the development of high concentration formulations of biologics

High concentration formulations have become an important pre-requisite in the development of biological drugs, particularly in the case of subcutaneous administration where limited injection volume negatively affects the administered dose. In this study, we propose to develop high concentration formulations of biologics using a reversible protein-polyelectrolyte complex (RPC) approach. First, the versatility of RPC was assessed using different complexing agents and formats of therapeutic proteins, to define the optimal conditions for complexation and dissociation of the complex. The stability of the protein was investigated before and after complexation, as well as upon a 4-week storage period at various temperatures. Subsequently, two approaches were selected to develop high concentration RPC formulations: first, using up-concentrated RPC suspensions in aqueous buffers, and second, by generating spray-dried RPC and further resuspension in non-aqueous solvents. Results showed that the RPC concept is applicable to a wide range of therapeutic protein formats and the complexation-dissociation process did not affect the stability of the proteins. High concentration formulations up to 200 mg/mL could be achieved by up-concentrating RPC suspensions in aqueous buffers and RPC suspensions in non-aqueous solvents were concentrated up to 250 mg/mL. Although optimization is needed, our data suggests that RPC may be a promising avenue to achieve high concentration formulations of biologics for subcutaneous administration.

Framework for creating a qualified medical device development tool of autoinjectors

Objectives

Autoinjectors are pivotal for precise self-administration of medications across a wide range of medical conditions. Nevertheless, the absence of a dedicated Medical Device Development Tool (MDDT) for autoinjectors represents a gap that may result in variations in the quality and regulatory compliance of autoinjectors as components of combination products. This research aim is to utilize the recently introduced Primary Functions outlined in ISO 11608-1:2022 with the title "Needle-based injection systems for medical use. Requirements and test methods. Part 1: Needle-based injection systems" to create a comprehensive MDDT framework tailored specifically for autoinjectors.

Methods

To support the creation of the framework, the analysis of the FDA MDDTs that were already approved, FDA's design controls regulations, FDA's guidance related to autoinjectors, and the Primary functions outlined in ISO 11608-1:2022 were utilized.

Results

The research identifies the Primary Functions in autoinjector to be Holding Force, Cap Removal Force, Activation Force, Extended Needle Length, Injection Time, Dose Accuracy and Needle Guard Lockout. Leveraging these Primary Functions and the FDA's MDDT approach, the research aims to bridge the gap by proposing a structured framework for the development of a specific MDDT tailored to autoinjectors.

Conclusion

This study presents a MDDT framework tailored to the development of autoinjectors for drug delivery. This framework provides a structured methodology to support predictability and effectiveness of the autoinjector development and support regulatory review process, thereby expediting FDA approval for autoinjectors as part of combination product.

Effects of arginine in therapeutic protein formulations: a decade review and perspectives

Arginine (Arg) is a natural amino acid with an acceptable safety profile and a unique chemical structure. Arg and its salts are highly effective in enhancing protein refolding and solubilization, suppressing protein-protein interaction and aggregation and reducing viscosity of high concentration protein formulations. Arg and its salts have been used in research and 20 approved protein injectables. This review summarizes the effects of Arg as an excipient in therapeutic protein formulations with the focus on its physicochemical properties, safety, applications in approved protein products, beneficial and detrimental effects in liquid and lyophilized protein formulations when combined with different counterions and mechanism on protein stabilization and destabilization. The decade literature review indicates that the benefits of Arg overweigh its risks when it is used appropriately. It is recommended to add Arg along with glutamate as a counterion to high concentration protein formulations on top of sugars or polyols to counterbalance the negative effects of Arg hydrochloride. The use of Arg as a viscosity reducer and protein stabilizer in high concentration formulations will be the inevitable future trend of the biopharmaceutical industry for subcutaneous administration.

Biophysical Determinants for the Viscosity of Concentrated Monoclonal Antibody Solutions

Monoclonal antibodies (mAbs) are particularly relevant for therapeutics due to their high specificity and versatility, and mAb-based drugs are hence used to treat numerous diseases. The increased patient compliance of self-administration motivates the formulation of products for subcutaneous (SC) administration. The associated challenge is to formulate highly concentrated antibody solutions to achieve a significant therapeutic effect, while limiting their viscosity and preserving their physicochemical stability. Protein-protein interactions (PPIs) are in fact the root cause of several potential problems concerning the stability, manufacturability, and delivery of a drug product. The understanding of macroscopic viscosity requires an in-depth knowledge on protein diffusion, PPIs, and self-association/aggregation. Here, we study the self-diffusion of different mAbs of the IgG1 subtype in aqueous solution as a function of the concentration and temperature by quasi-elastic neutron scattering (QENS). QENS allows us to probe the short-time self-diffusion of the molecules and therefore to determine the hydrodynamic mAb cluster size and to gain information on the internal mAb dynamics. Small-angle neutron scattering (SANS) is jointly employed to probe structural details and to understand the nature and intensity of PPIs. Complementary information is provided by molecular dynamics (MD) simulations and viscometry, thus obtaining a comprehensive picture of mAb diffusion.

Injectable hydrogel particles for amorphous solid formulation of biologics

The fast pace of breakthroughs in cancer immunotherapy, combined with the new paradigm of moving toward high-concentration dosages and combinatorial treatments, is generating new challenges in the formulation of biologics. To address these challenges, we describe a method of formulation that enables high-concentration injectable and stable formulation of biologics as amorphous solids in aqueous suspension. This technology combines the benefits of liquid formulation with the stability of solid formulation and eliminates the need for drying and reconstitution. This widely applicable formulation integrates the amorphous solid forms of antibodies with the injectability, lubricity, and tunability of soft alginate hydrogel particles using a minimal process. The platform was evaluated for anti-PD-1 antibody pembrolizumab and human immunoglobulin G at concentrations up to 300 mg/mL with confirmed quality after release. The soft nature of the hydrogel matrix allowed packing the particles to high volume fractions.

Poly(2-Hydroxyethyl Methacrylate) Hydrogel-Based Microneedles for Metformin Release

The release of metformin, a drug used in the treatment of cancer and diabetes, from poly(2-hydroxyethyl methacrylate), pHEMA, hydrogel-based microneedle patches is demonstrated in vitro. Tuning the composition of the pHEMA hydrogels enables preparation of robust microneedle patches with mechanical properties such that they would penetrate skin (insertion force of a single microneedle to be ≈40 N). Swelling experiments conducted at 20, 35, and 60 °C show temperature-dependent degrees of swelling and diffusion kinetics. Drug release from the pHEMA hydrogel-based microneedles is fitted to various models (e.g., zero order, first order, second order). Such pHEMA microneedles have potential application for transdermal delivery of metformin for the treatment of aging, cancer, diabetes, etc.

Application of Allometric Scaling to Nanochelator Pharmacokinetics

Deferoxamine (DFO) is an effective FDA-approved iron chelator; however, its use is considerably limited by off-target toxicities and an extremely cumbersome dose regimen involving daily infusions. The recent development of a deferoxamine-based nanochelator (DFO-NP) with selective renal excretion has shown promise in ameliorating iron overload and associated physiological complications in rodent models with a substantially improved safety profile. While the dose- and administration route-dependent pharmacokinetics (PK) of DFO-NPs have been recently characterized, the optimized PK model was not validated, and the prior studies did not directly address the clinical translatability of DFO-NPs into humans. In the present work, these gaps were addressed by applying allometric scaling of DFO-NP PK in rats to predict those in mice and humans. First, this approach predicted serum concentration-time profiles of DFO-NPs, which were similar to those experimentally measured in mice, validating the nonlinear disposition and absorption models for DFO-NPs across the species. Subsequently, we explored the utility of allometric scaling by predicting the PK profile of DFO-NPs in humans under clinically relevant dosing schemes. These in silico efforts demonstrated that the novel nanochelator is expected to improve the PK of DFO when compared to standard infusion regimens of native DFO. Moreover, reasonable formulation strategies were identified and discussed for both early clinical development and more sophisticated formulation development.

Effects of Intradermal Administration Volume Using a Hollow Microneedle on the Pharmacokinetics of Fluorescein Isothiocyanate Dextran (M.W. 4,000)

PURPOSE

Hollow microneedles (hMNs) have been gaining attention as a tool to enable the intradermal (i.d.) administration of pharmaceutical products. However, few reports have examined the effect of administration volume on distribution in the skin and pharmacokinetics parameters after i.d. injection. In the present study, a model middle molecular weight compound, fluorescein isothiocyanate dextran (M.W. 4,000, FD-4), was selected, and blood concentration-time profiles after i.d. and subcutaneous (s.c.) injections with different administration volumes were compared.

METHODS

FD-4 solution was injected i.d. using a hMN or injected s.c. with a 27 G needle. Pharmacokinetics and dermatokinetics of FD-4 were analyzed using a compartment model. The skin distribution of iodine, as an X ray tracer, was used to evaluate drug disposition.

RESULTS

With the administered drug assumed to be absorbed from the broad injection site into blood vessels in the upper and lower dermis by rapid (krapid) and slow (kslow) first-order absorption rate constants, respectively, better agreement of observed and theoretical values was obtained. Furthermore, the fraction, F, of the administered dose absorbed with krapid decreased with the increase in injection volume after i.d. injection, although the pharmacokinetics parameters were almost the same regardless of administration volume after s.c. injection.

CONCLUSION

The drug distribution in the skin may be related to the obtained pharmacokinetics parameters suggested that the number of needles in the MN system and the total administration volume should be considered in designing hMN systems. The present results provide useful information that may support effective drug delivery with hMNs.

Current status and prospect for future advancements of long-acting antibody formulations

INTRODUCTION

Biologics, especially monoclonal antibodies (mAbs), have become a major class of therapeutics in recent years addressing the needs of millions of patients and becoming one of the best-selling treatments in the pharmaceutical market. A wide range of multifaceted chronic diseases have benefitted from antibody therapeutics. Long-term treatment for chronic diseases with mAb therapies can mean a lifetime of frequent injections. Technologies that can minimize the total number of injections present meaningful value to patients and the companies that develop them.

AREAS COVERED

This review summarizes the challenges encountered during the development of long-acting versions of mAbs. The focus will be on questions addressed during drug product development, delivery device selection, business implications, and understanding the market potential of long-acting presentations.

EXPERT OPINION

Long-acting drug delivery systems have reached the market for small molecules and peptides. However, these drug delivery systems, and their development lessons, cannot be extrapolated directly to antibodies. We must develop new delivery technologies suitable for biologics, identify critical attributes to capture dynamic changes in proteins during the encapsulation process, and develop analytical processes to evaluate long-term stability.

A universal tool for stability predictions of biotherapeutics, vaccines and in vitro diagnostic products

It is of particular interest for biopharmaceutical companies developing and distributing fragile biomolecules to warrant the stability and activity of their products during long-term storage and shipment. In accordance with quality by design principles, advanced kinetic modeling (AKM) has been successfully used to predict long-term product shelf-life and relies on data from short-term accelerated stability studies that are used to generate Arrhenius-based kinetic models that can, in turn, be exploited for stability forecasts. The AKM methodology was evaluated through a cross-company perspective on stability modeling for key stability indicating attributes of different types of biotherapeutics, vaccines and biomolecules combined in in vitro diagnostic kits. It is demonstrated that stability predictions up to 3 years for products maintained under recommended storage conditions (2-8 °C) or for products that have experienced temperature excursions outside the cold-chain show excellent agreement with experimental real-time data, thus confirming AKM as a universal and reliable tool for stability predictions for a wide range of product types.

Effect of Various Silicone Oil and Tungsten Levels on the Stability of a Monoclonal Antibody in Nine Commercially Available Prefilled Syringes

Prefilled syringes are widely used as a primary container for therapeutic proteins because they are more convenient than glass vials. The stability of biologic molecules can be affected by different syringe materials and techniques, such as silicone oil levels and coating method, amount of tungsten remaining in the glass barrel after using a tungsten pin to create the needle hole, and end of the syringe, which can be Luer locked or pre-staked with a needle. We investigated the impact of these parameters by using a monoclonal antibody to collect the antibody's stability profile and the prefilled syringes' functionality data. Silicone oil levels had no impact on aggregation levels, and particle counts were lowest for silicone oil-free syringes. Functionality performance was similar and did not change throughout all stability time points for all syringe configurations. The break-loose force for Ompi syringes was initially lower and increased over time to align with those of the other configurations, all of which remained well below 25 N. Tungsten contaminants and agitation stress from shipping studies did not impact quality attributes. This work can help guide the development of similar products in prefilled syringes to ensure selection of the primary container that provides adequate stability for the protein, as well as maintain the desired functionality features over the shelf life of the drug product.

In-line warming reduces in-line pressure of subcutaneous infusion of concentrated immunoglobulins

Immunoglobulin replacement therapy is a life-saving treatment in patients with immunodeficiency and effective in the management of autoimmune disorders. Immunoglobulins are administered intravenously or subcutaneously, with the latter route reducing systemic reactions and providing an option for self-infusion, increasing patient convenience, while decreasing patient burden, healthcare utilization, and costs. A major limitation with subcutaneous administrations is the frequency of infusion due to limited volumes administrable into subcutaneous space, necessitating increased drug concentration, absorption, and dispersion. Increasing the concentration of immunoglobulins from 10 to 20% halves the required volume, but leads to higher dynamic viscosity, limiting infusion rate. Recombinant human hyaluronidase increases dispersion and absorption of immunoglobulins allowing administration of ≤ 600 mL per site, but does not change viscosity. Since the viscosity of fluids depends on temperature, we tested the feasibility of in-line warming of immunoglobulin formulations to physiological temperatures. In vitro analysis showed no negative impact of in-line warming to 38 °C on product quality. Subcutaneous infusion studies in pigs confirmed the feasibility of infusion rates of up to 7.5 mL/min with in-line warmed TAK-881, an immunoglobulin 20% facilitated with recombinant human hyaluronidase. In-line pressures were reduced compared with conventional immunoglobulin 20%, and local tolerance was not altered. Reduction of in-line pressures was more pronounced with thinner needle sets, indicating a potential benefit for patients. In summary, an in in-line warming device can circumvent the limitation of high viscosity, while product quality and local tolerance are maintained. The results of the presented studies warrant further testing in a phase 1 clinical study.

Subcutaneous delivery of an antibody against SARS-CoV-2 from a supramolecular hydrogel depot

Prolonged maintenance of therapeutically-relevant levels of broadly neutralizing antibodies (bnAbs) is necessary to enable passive immunization against infectious disease. Unfortunately, protection only lasts for as long as these bnAbs remain present at a sufficiently high concentration in the body. Poor pharmacokinetics and burdensome administration are two challenges that need to be addressed in order to make pre- and post-exposure prophylaxis with bnAbs feasible and effective. In this work, we develop a supramolecular hydrogel as an injectable, subcutaneous depot to encapsulate and deliver antibody drug cargo. This polymer-nanoparticle (PNP) hydrogel exhibits shear-thinning and self-healing properties that are required for an injectable drug delivery vehicle. In vitro drug release assays and diffusion measurements indicate that the PNP hydrogels prevent burst release and slow the release of encapsulated antibodies. Delivery of bnAbs against SARS-CoV-2 from PNP hydrogels is compared to standard routes of administration in a preclinical mouse model. We develop a multi-compartment model to understand the ability of these subcutaneous depot materials to modulate the pharmacokinetics of released antibodies; the model is extrapolated to explore the requirements needed for novel materials to successfully deliver relevant antibody therapeutics with different pharmacokinetic characteristics.

Imaging of large volume subcutaneous deposition using MRI: exploratory clinical study results

Subcutaneous (SC) delivery is a preferred route of administration for biotherapeutics but has predominantly been limited to volumes below 3 mL. With higher volume drug formulations emerging, understanding large volume SC (LVSC) depot localization, dispersion, and impact on the SC environment has become more critical. The aim of this exploratory clinical imaging study was to assess the feasibility of magnetic resonance imaging (MRI) to identify and characterize LVSC injections and their effect on SC tissue as a function of delivery site and volume. Healthy adult subjects received incremental injections of normal saline up to 5 mL total volume in the arm and up to 10 mL in the abdomen and thigh. MRI images were acquired after each incremental SC injection. Post-image analysis was performed to correct imaging artifacts, identify depot tissue location, create 3-dimensional (3D) SC depot rendering, and estimate in vivo bolus volumes and SC tissue distention. LVSC saline depots were readily achieved, imaged using MRI, and quantified via subsequent image reconstructions. Imaging artifacts occurred under some conditions, necessitating corrections applied during image analysis. 3D renderings were created for both the depot alone and in relation to the SC tissue boundaries. LVSC depots remained predominantly within the SC tissue and expanded with increasing injection volume. Depot geometry varied across injection sites and localized physiological structure changes were observed to accommodate LVSC injection volumes. MRI is an effective means to clinically visualize LVSC depots and SC architecture allowing assessment of deposition and dispersion of injected formulations.Trial Registration: Not applicable for this exploratory clinical imaging study.

Delivering on the promise of protein degraders

Over the past 3 years, the first bivalent protein degraders intentionally designed for targeted protein degradation (TPD) have advanced to clinical trials, with an initial focus on established targets. Most of these clinical candidates are designed for oral administration, and many discovery efforts appear to be similarly focused. As we look towards the future, we propose that an oral-centric discovery paradigm will overly constrain the chemical designs that are considered and limit the potential to drug novel targets. In this Perspective, we summarize the current state of the bivalent degrader modality and propose three categories of degrader designs, based on their likely route of administration and requirement for drug delivery technologies. We then describe a vision for how parenteral drug delivery, implemented early in research and supported by pharmacokinetic-pharmacodynamic modelling, can enable exploration of a broader drug design space, expand the scope of accessible targets and deliver on the promise of protein degraders as a therapeutic modality.

Facile Technology for Extemporaneous Preparation of Long-Acting Injectable Microparticulate Suspensions at the Patient Side

In this study, we present an innovative and facile in situ approach for extemporaneous preparation of sterile microparticles. An amazingly simple approach, in situ technology circumvents the stability, and scale up challenges as well as sterilization issues associated with long-acting particulate systems. Monophasic preconcentrates of donepezil base (DPZ), a model drug with a biodegradable polymer poly (DL-lactide-co-glycolide) (PLGA), with stabilizer were prepared by simple solution and sterilized by filtration (0.22 micron). The sterile preconcentrates when added to aqueous dextrose solution (total volume < 3 mL) generated ready-to-inject DPZ PLGA microparticles (DPZ-PLGA-MP) with high reproducibility, entrapment efficiency (> 80%), and size ~ 80 micron. DPZ micro suspension (DPZ-MS) with high precipitation efficiency (> 90%) and size ~ 80 micron was obtained in a similar manner omitting PLGA. XRD and DSC study confirmed decreased crystallinity in the presence of PLGA. No interaction between PLGA and DPZ was evident in the FTIR study. The microparticulate dispersions exhibited good in vitro injectability when tested using the texture analyzer (force < 5 N). When evaluated using the dialysis bag method (Himedia 12-14 kDa molecular weight cutoff), both microparticulate formulations exhibited controlled release up to 1 week in vitro. Further, low burst release of ~ 10% at the end of 6 h in the ex vivo chicken muscle study proposes great promise. Our data propose the facile extemporaneous generation of microparticles as a practical and promising approach for development of long-acting injectables. This facile approach could serve as platform technology for other drug candidates.

An Intercompany Perspective on Practical Experiences of Predicting, Optimizing and Analyzing High Concentration Biologic Therapeutic Formulations

Developing high-dose biologic drugs for subcutaneous injection often requires high-concentration formulations and optimizing viscosity, solubility, and stability while overcoming analytical, manufacturing, and administration challenges. To understand industry approaches for developing high-concentration formulations, the Formulation Workstream of the BioPhorum Development Group, an industry-wide consortium, conducted an inter-company collaborative exercise which included several surveys. This collaboration provided an industry perspective, experience, and insight into the practicalities for developing high-concentration biologics. To understand solubility and viscosity, companies desire predictive tools, but experience indicates that these are not reliable and experimental strategies are best. Similarly, most companies prefer accelerated and stress stability studies to in-silico or biophysical-based prediction methods to assess aggregation. In addition, optimization of primary container-closure and devices are pursued to mitigate challenges associated with high viscosity of the formulation. Formulation strategies including excipient selection and application of studies at low concentration to high-concentration formulations are reported. Finally, analytical approaches to high concentration formulations are presented. The survey suggests that although prediction of viscosity, solubility, and long-term stability is desirable, the outcome can be inconsistent and molecule dependent. Significant experimental studies are required to confirm robust product definition as modeling at low protein concentrations will not necessarily extrapolate to high concentration formulations.

Understanding patient preferences for handheld autoinjectors versus wearable large-volume injectors

OBJECTIVE

While interest in the use of wearable large-volume injectors for subcutaneous drug delivery is increasing, it remains unclear whether and under what conditions these emerging dosing options are preferred over more frequent but shorter administration of smaller doses using handheld autoinjectors. Therefore, the objective of this study was to examine the characteristics of patients diagnosed with cancer, diabetes, inflammatory and cardiovascular diseases, and treatment attributes that determine device preferences.

METHODS

Based on a cross-sectional online choice experiment, 191 participants expressed their preferences without being physically exposed to the devices or performing injections. Logistic hierarchical regression models were used to assess which patient characteristics, and how changes in treatment attributes, drive device preferences.

RESULTS

Participant quality of life reduced the likelihood of preferring wearable large-volume injectors to handheld autoinjectors. Moreover, reducing injection frequency from biweekly to monthly to quarterly injections, and shortening injection duration from 33 to 8 min, significantly increased the likelihood of patients preferring large-volume injectors to autoinjectors (p < 0.001).

CONCLUSION

The study revealed patient quality of life as predictor of device preference and identified critical inflection points in injection duration and injection frequency, at which patient preferences shift from handheld autoinjectors to wearable large-volume injectors.

Monoclonal antibody and protein therapeutic formulations for subcutaneous delivery: high-concentration, low-volume vs. low-concentration, high-volume

Biologic drugs are used to treat a variety of cancers and chronic diseases. While most of these treatments are administered intravenously by trained healthcare professionals, a noticeable trend has emerged favoring subcutaneous (SC) administration. SC administration of biologics poses several challenges. Biologic drugs often require higher doses for optimal efficacy, surpassing the low volume capacity of traditional SC delivery methods like autoinjectors. Consequently, high concentrations of active ingredients are needed, creating time-consuming formulation obstacles. Alternatives to traditional SC delivery systems are therefore needed to support higher-volume biologic formulations and to reduce development time and other risks associated with high-concentration biologic formulations. Here, we outline key considerations for SC biologic drug formulations and delivery and explore a paradigm shift: the flexibility afforded by low-to-moderate-concentration drugs in high-volume formulations as an alternative to the traditionally difficult approach of high-concentration, low-volume SC formulation delivery.

Developability Assessments of Monoclonal Antibody Candidates to Minimize Aggregation During Large-Scale Ultrafiltration and Diafiltration (UF-DF) Processing

Therapeutic proteins are subjected to a variety of stresses during manufacturing, storage or administration, that often lead to undesired protein aggregation and particle formation. Ultrafiltration-diafiltration (UF-DF) processing of monoclonal antibodies (mAbs) is one such manufacturing step that has been shown to result in such physical degradation. In this work, we explore the use of different analytical techniques and lab-scale setups as methodologies to predict and rank-order the aggregation potential of four different mAbs during large-scale UF-DF processing. In the first part of the study, a suite of biophysical techniques was applied to assess differences in their inherent bulk protein properties including conformational and colloidal stability in a PBS buffer. Additionally, the inherent interfacial properties of these mAbs in PBS were measured using a Langmuir trough technique. In the next part of the study, several different scale-down lab models were evaluated including a lab bench-scale UF-DF setup, mechanical stress (shaking/stirring) studies in vials, and application of interfacial dilatational stress using a Langmuir trough to assess protein particle formation in different UF-DF processing buffers. Taken together, our results demonstrate the ability of a Langmuir-trough methodology to accurately predict the mAb instability profile observed during large scale UF-DF processing.

Enabling faster subcutaneous delivery of larger volume, high viscosity fluids

OBJECTIVES

Many current subcutaneous (SC) biologic therapies may require >1 mL volume or have increased viscosity, necessitating new delivery system approaches. This study evaluated 2-mL large-volume autoinjector (LVAI) delivery performance across varying solution viscosities and design inputs to assess the design space and identify configurations that produce practical injection times.

METHODS

Investigational LVAI delivery duration and volume, depot location, and tissue effects were examined in both air and in vivo models across various pre-filled syringe (PFS) cannula types (27 G Ultra-thin wall [UTW], 27 G special thin wall [STW], or 29 G thin-wall [TW]), drive spring forces (SF_LOW or SF_HIGH), and Newtonian solutions (2.3-50 centipoise [cP]).

RESULTS

Within each design configuration, increasing PFS internal diameters and spring forces reduced delivery times, while increasing viscosity increased times. The 27 G UTW PFS/SF_HIGH combination achieved shorter delivery times across all injection conditions, with 2 mL in vivo durations <15 seconds at ≤31 cP and routinely <20 seconds at 39 and 51 cP, with nominal and transitory tissue effects.

CONCLUSION

PFS cannula and spring force combinations can be tailored to achieve various injection durations across viscosities, while UTW PFS enables faster rates to potentially better accommodate human factors during LVAI injection, especially at high viscosity.

Subcutaneous delivery of an antibody against SARS-CoV-2 from a supramolecular hydrogel depot

Prolonged maintenance of therapeutically-relevant levels of broadly neutralizing antibodies (bnAbs) is necessary to enable passive immunization against infectious disease. Unfortunately, protection only lasts for as long as these bnAbs remain present at a sufficiently high concentration in the body. Poor pharmacokinetics and burdensome administration are two challenges that need to be addressed in order to make pre- and post-exposure prophylaxis with bnAbs feasible and effective. In this work, we develop a supramolecular hydrogel as an injectable, subcutaneous depot to encapsulate and deliver antibody drug cargo. This polymer-nanoparticle (PNP) hydrogel exhibits shear-thinning and self-healing properties that are required for an injectable drug delivery vehicle. In vitro drug release assays and diffusion measurements indicate that the PNP hydrogels prevent burst release and slow the release of encapsulated antibodies. Delivery of bnAbs against SARS-CoV-2 from PNP hydrogels is compared to standard routes of administration in a preclinical mouse model. We develop a multi-compartment model to understand the ability of these subcutaneous depot materials to modulate the pharmacokinetics of released antibodies; the model is extrapolated to explore the requirements needed for novel materials to successfully deliver relevant antibody therapeutics with different pharmacokinetic characteristics.

Opalescence Arising from Network Assembly in Antibody Solution

Opalescence of therapeutic antibody solutions is one of the concerns in drug formulation. However, the mechanistic insights into the opalescence of antibody solutions remain unclear. Here, we investigated the assembly states of antibody molecules as a function of antibody concentration. The solutions of bovine gamma globulin and human immunoglobulin G at around 100 mg/mL showed the formation of submicron-scale network assemblies. The network assembly resulted in the appearance of opalescence with a transparent blue color without the precipitates of antibodies. Furthermore, the addition of trehalose and arginine, previously known to act as protein stabilizers and protein aggregation suppressors, was able to suppress the opalescence arising from the network assembly. These results will provide an important information for evaluating and improving protein formulations.