Enabling technologies driving drug research and development

One of the strategic goals of the European Medicines Agency (EMA) and the European Medicines Regulatory Network is to support the research and uptake of innovative methods and technologies in the development of medicines. To promote this goal, EMA drew up a list of enabling technologies (ETs), which are novel and fast-growing technologies that have the potential to enable innovation and therefore exert considerable impact on drug development. In this work, enabling technologies identified by the EMA are analysed to measure their impact on drug development by following their journey from publications through early regulatory interactions to clinical trials between 2019 and 2022. This work also reviews the current list of EMA-identified ETs by scrutinising previously unseen innovative technologies identified in EMA submissions data. The analysis shows large variations in the appearance of the various innovative technologies in the different studied data sources, which provided valuable insights into the “Journey of Innovation” that innovative technologies undergo. Several emerging technologies were identified and endorsed for inclusion in the enabling technologies list, whereas some others already on the list were proposed to be excluded due to their low appearance in regulatory interactions as well as clinical trials and publications. Overall, this analysis highlights the relevance and value of continuously scanning and monitoring enabling technologies, supporting Europe’s goal to remain a leader in research and development of innovative technologies, methods, and methodologies relevant to drug development.

Oligonucleotide Formulations Prepared by High-Speed Electrospinning: Maximizing Loading and Exploring Downstream Processability

The aim of this study was to develop antisense oligonucleotide tablet formulations using high-speed electrospinning. Hydroxypropyl-beta-cyclodextrin (HPβCD) was used as a stabilizer and as an electrospinning matrix. In order to optimize the morphology of the fibers, electrospinning of various formulations was carried out using water, methanol/water (1:1), and methanol as solvents. The results showed that using methanol could be advantageous due to the lower viscosity threshold for fiber formation enabling higher potential drug loadings by using less excipient. To increase the productivity of electrospinning, high-speed electrospinning technology was utilized and HPβCD fibers containing 9.1% antisense oligonucleotide were prepared at a rate of ~330 g/h. Furthermore, to increase the drug content of the fibers, a formulation with a 50% drug loading was developed. The fibers had excellent grindability but poor flowability. The ground fibrous powder was mixed with excipients to improve its flowability, which enabled the automatic tableting of the mixture by direct compression. The fibrous HPβCD–antisense oligonucleotide formulations showed no sign of physical or chemical degradation over the 1-year stability study, which also shows the suitability of the HPβCD matrix for the formulation of biopharmaceuticals. The obtained results demonstrate possible solutions for the challenges of electrospinning such as scale-up and downstream processing of the fibers.

Powder filling of electrospun material in vials: A proof-of-concept study

The present paper reports the powder filling of milled electrospun materials in vials, which contained voriconazole and sulfobutylether-β-cyclodextrin. High-speed electrospinning was used for the production of the fibrous sample, which was divided into 6 parts. Each portion was milled using different milling methods and sizes of sieves to investigate whether the milling influences the powder and filling properties. Bulk and tapped density tests, laser diffraction and angle of repose measurements were applied to characterize the milled powders, while a vibratory feeder was used for the feeding experiments. The correlation between the material property descriptors and the feeding responses was investigated by multivariate data analysis. Based on the results, three samples were chosen for the vial filling, which was accomplished with 3400 mg electrospun material containing 200 mg voriconazole, representative of the commercial product. The feed rate was set to fit the 240 g/h production rate of the electrospinning and the relative standard deviation of three repeated vial filling was determined to see the accuracy of the process. This research shows that by applying a suitable milling method it is possible to process electrospun fibers to a powder, which can be filled into vials and used as reconstitution dosage forms.

Sulfobutylether-beta-cyclodextrin-enabled antiviral remdesivir: Characterization of electrospun- and lyophilized formulations

Veklury™ by Gilead Sciences, Inc., containing antiviral drug, remdesivir (REM) has received emergency authorization in the USA and in Europe for COVID-19 therapy. Here, for the first time, we describe details of the non-covalent, host-guest type interaction between REM and the solubilizing excipient, sulfobutylether-beta-cyclodextrin (SBECD) that results in significant solubility enhancement. Complete amorphousness of the cyclodextrin-enabled REM formulation was demonstrated by X-ray diffraction, thermal analysis, Raman chemical mapping and electron microscopy/energy dispersive spectroscopy. The use of solubilizing carbohydrate resulted in a 300-fold improvement of the aqueous solubility of REM, and enhanced dissolution rate of the drug enabling the preparation of stable infusion solutions for therapy. 2D ROESY NMR spectroscopy provided information on the nature of REM-excipient interaction and indicated the presence of inclusion phenomenon and the electrostatic attraction between anionic SBECD and nitrogen-containing REM in aqueous solution.

Continuous blending monitored and feedback controlled by machine vision-based PAT tool

In a continuous powder blending process machine vision is utilized as a Process Analytical Technology (PAT) tool. While near-infrared (NIR) and Raman spectroscopy are reliable methods in this field, measurements become challenging when concentrations below 2 w/w% are quantified. However, an active pharmaceutical ingredient (API) with an intense color might be quantified in even lower quantities by images recorded with a digital camera. Riboflavin (RI) was used as a model API with orange color, its Limit of Detection was found to be 0.015 w/w% and the Limit of Quantification was 0.046 w/w% using a calibration based on the pixel value of images. A calibration for in-line measurement of RI concentration was prepared in the range of 0.2-0.45 w/w%, validation with UV/VIS spectrometry showed great accuracy with a relative error of 2.53 %. The developed method was then utilized for a residence time distribution (RTD) measurement in order to characterize the dynamics of the blending process. Lastly, the technique was applied in real-time feedback control of a continuous powder blending process. Machine vision based direct or indirect API concentration determination is a promising and fast method with a great potential for monitoring and control of continuous pharmaceutical processes.

Comparison of Amorphous Solid Dispersions of Spironolactone Prepared by Spray Drying and Electrospinning: The Influence of the Preparation Method on the Dissolution Properties

This research aimed to compare two solvent-based methods for the preparation of amorphous solid dispersions (ASDs) made up of poorly soluble spironolactone and poly(vinylpyrrolidone-co-vinyl acetate). The same apparatus was used to produce, in continuous mode, drug-loaded electrospun (ES) and spray-dried (SD) materials from dichloromethane and ethanol-containing solutions. The main differences between the two preparation methods were the concentration of the solution and application of high voltage. During electrospinning, a solution with a higher concentration and high voltage was used to form a fibrous product. In contrast, a dilute solution and no electrostatic force were applied during spray drying. Both ASD products showed an amorphous structure according to differential scanning calorimetry and X-ray powder diffraction results. However, the dissolution of the SD sample was not complete, while the ES sample exhibited close to 100% dissolution. The polarized microscopy images and Raman microscopy mapping of the samples highlighted that the SD particles contained crystalline traces, which can initiate precipitation during dissolution. Investigation of the dissolution media with a borescope made the precipitated particles visible while Raman spectroscopy measurements confirmed the appearance of the crystalline active pharmaceutical ingredient. To explain the micro-morphological differences, the shape and size of the prepared samples, the evaporation rate of residual solvents, and the influence of the electrostatic field during the preparation of ASDs had to be considered. This study demonstrated that the investigated factors have a great influence on the dissolution of the ASDs. Consequently, it is worth focusing on the selection of the appropriate ASD preparation method to avoid the deterioration of dissolution properties due to the presence of crystalline traces.

Monoclonal antibody formulation manufactured by high-speed electrospinning

Solid formulations of monoclonal antibodies present several advantages, such as improved stability and increased shelf-life as well as simpler storage and transportation. In this study, we present a gentle drying technology for monoclonal antibodies, applying the water soluble 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) as matrix, to prepare a solid reconstitution dosage form. High-speed electrospinning of an aqueous infliximab-containing HP-β-CD solution was carried out at 25 °C resulting in fibers with an average diameter of 2.5 μm. The mAb-loaded electrospun fibers were successful to preserve the stability of infliximab in solid form. The results of size exclusion chromatography and gel electrophoresis indicated no significant increase in aggregate formation during the electrospinning process compared to the initial matrix solution. The binding activity of infliximab was preserved during electrospinning compared to the reference liquid formulation. Due to the enhanced surface area, excellent reconstitution capability, i.e. clear solution within 2 min without any vigorous mixing, could be achieved in a small-scale reconstitution test. The results of this work demonstrate that high-speed electrospinning is a very promising technique to manufacture the solid formulation of monoclonal antibodies for applications such as fast reconstitutable powders.

Electrospun Solid Formulation of Anaerobic Gut Microbiome Bacteria

A model anaerobic bacterium strain from the gut microbiome (Clostridium butyricum) producing anti-inflammatory molecules was incorporated into polymer-free fibers of a water-soluble cyclodextrin matrix (HP-β-CD) using a promising scaled-up nanotechnology, high-speed electrospinning. A long-term stability study was also carried out on the bacteria in the fibers. Effect of storage conditions (temperature, presence of oxygen) and growth conditions on the bacterial viability in the fibers was investigated. The viability of the sporulated anaerobic bacteria in the fibers was maintained during 12 months of room temperature storage in the presence of oxygen. Direct compression was used to prepare tablets from the produced bacteria-containing fibers after milling (using an oscillating mill) and mixing with tableting excipients, making easy oral administration of the bacteria possible. No significant decrease was observed in bacterial viability following the processing of the fibers (milling and tableting).

Raman-based dynamic feeding strategies using real-time glucose concentration monitoring system during adalimumab producing CHO cell cultivation

The use of Process Analytical Technology tools coupled with chemometrics has been shown great potential for better understanding and control of mammalian cell cultivations through real-time process monitoring. In-line Raman spectroscopy was utilized to determine the glucose concentration of the complex bioreactor culture medium ensuring real-time information for our process control system. This work demonstrates a simple and fast method to achieve a robust partial least squares calibration model under laboratory conditions in an early phase of the development utilizing shake flask and bioreactor cultures. Two types of dynamic feeding strategies were accomplished where the multi-component feed medium additions were controlled manually and automatically based on the Raman monitored glucose concentration. The impact of these dynamic feedings was also investigated and compared to the traditional bolus feeding strategy on cellular metabolism, cell growth, productivity, and binding activity of the antibody product. Both manual and automated dynamic feeding strategies were successfully applied to maintain the glucose concentration within a narrower and lower concentration range. Thus, besides glucose, the glutamate was also limited at low level leading to reduced production of inhibitory metabolites, such as lactate and ammonia. Consequently, these feeding control strategies enabled to provide beneficial cultivation environment for the cells. In both experiments, higher cell growth and prolonged viable cell cultivation were achieved which in turn led to increased antibody product concentration compared to the reference bolus feeding cultivation.

Continuous Formulation Approaches of Amorphous Solid Dispersions: Significance of Powder Flow Properties and Feeding Performance

Preparation and formulation of amorphous solid dispersions (ASDs) are becoming more and more popular in the pharmaceutical field because the dissolution of poorly water-soluble drugs can be effectively improved this way, which can lead to increased bioavailability in many cases. During downstream processing of ASDs, technologists need to keep in mind both traditional challenges and the newest trends. In the last decade, the pharmaceutical industry began to display considerable interest in continuous processing, which can be explained with their potential advantages such as smaller footprint, easier scale-up, and more consistent product, better quality and quality assurance. Continuous downstream processing of drug-loaded ASDs opens new ways for automatic operation. Therefore, the formulation of poorly water-soluble drugs may be more effective and safe. However, developments can be challenging due to the poor flowability and feeding properties of ASDs. Consequently, this review pays special attention to these characteristics since the feeding of the components greatly influences the content uniformity in the final dosage form. The main purpose of this paper is to summarize the most important steps of the possible ASD-based continuous downstream processes in order to give a clear overview of current course lines and future perspectives.

Continuous alternative to freeze drying: Manufacturing of cyclodextrin-based reconstitution powder from aqueous solution using scaled-up electrospinning

The aims of this study were to evaluate electrospinning as a continuous alternative to freeze drying in the production of a reconstitution injection dosage form, and to prove that aqueous electrospinning can be realized with a high production rate at room temperature. High-speed electrospinning with a novel continuous cyclone collection was used to manufacture a formulation of the poorly water-soluble antifungal voriconazole (VOR) with sulfobutylether-β-cyclodextrin (SBE-β-CD). The freeze-dried, marketed product of this drug substance, Vfend® also contains SBE-β-CD as excipient. SBE-β-CD acted as a 'quasi-polymer', and it could be electrospun despite its low molecular mass (2163 Da). According to X-ray diffraction and differential scanning calorimetry, no traces of crystalline VOR were detectable in the fibers. Furthermore, Raman mapping and energy dispersive spectroscopy measurements showed a uniform distribution of amorphous VOR in the fibers. Reconstitution tests carried out with ground fibrous powder showed complete dissolution resulting in a clear solution after 30 s (similarly to Vfend®). The high productivity rate (~240 g/h) achieved using high-speed electrospinning makes this scaled-up, continuous and flexible manufacturing process capable of fulfilling the technological and capacity requirements of the pharmaceutical industry. This work shows that aqueous high-speed electrospinning, being a continuous and high-throughput process, is an economically viable production alternative to freeze drying.

Drying technology strategies for colon-targeted oral delivery of biopharmaceuticals

In chronic intestinal diseases like inflammatory bowel disease, parenteral administration of biopharmaceuticals is associated with numerous disadvantages including immune reactions, infections, low patient compliance, and toxicity caused by high systemic bioavailability. One alternative that can potentially overcome these limitations is oral administration of biopharmaceuticals, where the local delivery will reduce the systemic exposure and furthermore the manufacturing costs will be lower. However, the development of oral dosage forms that deliver the biologically active form to the intestines is one of the greatest challenges for pharmaceutical technologists due to the sensitive nature of biopharmaceuticals. The present article discusses the various drug delivery technologies used to produce orally administered solid dosage forms of biopharmaceuticals with an emphasis on colon-targeted delivery. Solid oral dosage compositions containing different types of colon-targeting biopharmaceuticals are compiled followed by a review of currently applied and emerging drying technologies for biopharmaceuticals. The different drying technologies are compared in terms of their advantages, limitations, costs and their effect on product stability.

Raman Spectroscopy for Process Analytical Technologies of Pharmaceutical Secondary Manufacturing

As the process analytical technology (PAT) mindset is progressively introduced and adopted by the pharmaceutical companies, there is an increasing demand for effective and versatile real-time analyzers to address the quality assurance challenges of drug manufacturing. In the last decades, Raman spectroscopy has emerged as one of the most promising tools for non-destructive and fast characterization of the pharmaceutical processes. This review summarizes the achieved results of the real-time application of Raman spectroscopy in the field of the secondary manufacturing of pharmaceutical solid dosage forms, covering the most common secondary process steps of a tablet production line. In addition, the feasibility of Raman spectroscopy for real-time control is critically reviewed, and challenges and possible approaches to moving from real-time monitoring to process analytically controlled technologies (PACT) are discussed.