Quality by Design Considerations for Drop-on-Demand Point-of-Care Pharmaceutical Manufacturing of Precision Medicine

Distributed and point-of-care (POC) manufacturing facilities enable an agile pharmaceutical production paradigm that can respond to localized needs, providing personalized and precision medicine. These capabilities are critical for narrow therapeutic index drugs and pediatric or geriatric dosing, among other specialized needs. Advanced additive manufacturing, three-dimensional (3D) printing, and drop-on-demand (DoD) dispensing technologies have begun to expand into pharmaceutical production. We employed a quality by design (QbD) approach to identify critical quality attributes (CQAs), critical material attributes (CMAs), and critical process parameters (CPPs) of a POC pharmaceutical manufacturing paradigm. This theoretical framework encompasses the production of active pharmaceutical ingredient (API) "inks" at a centralized facility, which are distributed to POC sites for DoD dispensing into/onto delivery vehicles (e.g., orodispersible films, capsules, single liquid dose vials). Focusing on the POC dispensing/dosing processes, QbD considerations and cause-and-effect analyses identified the dispensed API quantity and solid-state form (CQAs), as well as the nozzle diameter, system pressure channel, and number of drops dispensed (CPPs) for detailed investigation. Final assay quantification and content uniformity CQAs were measured from demonstrative levothyroxine sodium single-dose liquid vials of glycerin/water, meeting the standard acceptance values. Each POC facility is unlikely to maintain full quality control laboratory capabilities, requiring the development of appropriate atline or inline methods to ensure quality control. We developed control strategies, including atline ultraviolet-visible (UV-vis) verification of the API ink prior to dispensing, inline drop counting during dispensing, intermediate atline-dispensed volume checks, and offline batch confirmation by liquid chromatography-tandem mass spectrometry (LC-MS/MS) following production.

Developing a Modular Continuous Drug Product Manufacturing System with Real Time Quality Assurance for Producing Pharmaceutical Mini-Tablets

The pharmaceutical industry has shown keen interest in developing small-scale modular manufacturing systems for producing medicinal products. These systems offer agile and flexible manufacturing, and are well-suited for use in situations requiring rapid production of drugs such as pandemics and humanitarian disasters. The creation of such systems requires the development of modular facilities for making solid oral drug products. In recent years, however, the development of such facilities has seen limited progress. This study presents a development of a prototype modular system that uses drop on demand (DoD) printing to produce personalized solid oral drug products. The system's operation is demonstrated for manufacturing mini-tablets, a category of pediatric drug products, in continuous and semi-batch modes. In this process, the DoD printer is used to generate molten formulation drops that are solidified into mini-tablets. These dosages are then extracted, washed and dried in a continuous filtration and drying unit which is integrated with the printer. Process monitoring tools are also incorporated in the system to track the critical quality attributes of the product and the critical process parameters of the manufacturing operation in real time. Future areas of innovation are also proposed to improve this prototype unit and to enable the development of advanced drug manufacturing systems based on this platform.

Potential Applications and Additive Manufacturing Technology-Based Considerations of Mesoporous Silica: A Review

Nanoporous materials are categorized as microporous (pore sizes 0.2-2 nm), mesoporous (pore sizes 2-50 nm), and macroporous (pore sizes 50-1000 nm). Mesoporous silica (MS) has gained a significant interest due to its notable characteristics, including organized pore networks, specific surface areas, and the ability to be integrated in a variety of morphologies. Recently, MS has been widely accepted by range of manufacturer and as drug carrier. Moreover, silica nanoparticles containing mesopores, also known as mesoporous silica nanoparticles (MSNs), have attracted widespread attention in additive manufacturing (AM). AM commonly known as three-dimensional printing is the formalized rapid prototyping (RP) technology. AM techniques, in comparison to conventional methods, aid in reducing the necessity for tooling and allow versatility in product and design customization. There are generally several types of AM processes reported including VAT polymerization (VP), powder bed fusion (PBF), sheet lamination (SL), material extrusion (ME), binder jetting (BJ), direct energy deposition (DED), and material jetting (MJ). Furthermore, AM techniques are utilized in fabrication of various classified fields such as architectural modeling, fuel cell manufacturing, lightweight machines, medical, and fabrication of drug delivery systems. The review concisely elaborates on applications of mesoporous silica as versatile material in fabrication of various AM-based pharmaceutical products with an elaboration on various AM techniques to reduce the knowledge gap.

Manufacturing pharmaceutical mini-tablets for pediatric patients using drop-on-demand printing

The pharmaceutical industry has traditionally manufactured medicines in a limited range of dose strengths, with an emphasis on addressing the needs of the largest patient subgroups. This has disadvantaged smaller patient subsets, such as children, who often cannot find drug products in dosage levels suitable for their requirements. In recent years, development of pharmaceutical mini-tablets has emerged as an attractive solution to this problem. These are small-size dosages that offer attractive features such as flexible and personalized drug dosing, ease of swallowing, and tailored drug release, making them an excellent choice for administering medicines to children. This study presents a novel technique for manufacturing pharmaceutical mini-tablets, using a drop-on-demand (DoD) printing system. In this method, a DoD system is used to generate precise droplets of a melt-based formulation, which are then captured and solidified in an inert solvent bath to produce individual mini-tablets. The study also evaluates the performance of this technique for various formulations, and quantifies two critical quality attributes (CQAs) of the resulting mini-tablets: content uniformity and dissolution behavior. The findings demonstrate that the manufactured mini-tablets can meet regulatory specifications for both CQAs, and that their release profiles can be customized by modifying the excipients used. The study also discusses promising areas of application and limitations of this technique.

Developing a machine learning enabled integrated formulation and process design framework for a pharmaceutical dropwise additive manufacturing printer

The pharmaceutical manufacturing sector needs to rapidly evolve to absorb the next wave of disruptive industrial innovations - Industry 4.0. This involves incorporating technologies like artificial intelligence, smart factories and 3D printing to automate, miniaturize and personalize the production processes. The goal of this study is to build a formulation and process design (FPD) framework for a pharmaceutical 3D printing technique called drop-on-demand (DoD) printing. FPD can automate the determination of formulation properties and printing conditions (input conditions) for DoD operation that can guarantee production of drug products with desired functional attributes. This study proposes to build the FPD framework in two parts: the first part involves building a machine learning model to simulate the forward problem - predicting DoD operation based on input conditions and the second part seeks to solve and experimentally validate the inverse problem - predicting input conditions that can yield desired DoD operation.

Needles to Spheres: Evaluation of inkjet printing as a particle shape enhancement tool

Active pharmaceutical ingredients (APIs) often reveal shapes challenging to process, e.g. acicular structures, and exhibit reduced bioavailability induced by slow dissolution rate. Leveraging the API particles' surface and bulk properties offers an attractive pathway to circumvent these challenges. Inkjet printing is an attractive processing technique able to tackle these limitations already in initial stages when little material is available, while particle properties are maintained over the entire production scale. Additionally, it is applicable to a wide range of formulations and offers the possibility of co-processing with a variety of excipients to improve the API's bioavailability. This study addresses the optimization of particle shapes for processability enhancement and demonstrates the successful application of inkjet printing to engineer spherical lacosamide particles, which are usually highly acicular. By optimizing the ink formulation, adapting the substrate-liquid interface and tailoring the heat transfer to the particle, spherical particles in the vicinity of 100 µm, with improved flow properties compared to the bulk material, were produced. Furthermore, the particle size was tailored reproducibly by adjusting the deposited ink volume per cycle and the number of printing cycles. Therefore, the present study shows a novel, reliable, scalable and economical strategy to overcome challenging particle morphologies by co-processing an API with suitable excipients.

Influence of the Volatility of Solvent on the Reproducibility of Droplet Formation in Pharmaceutical Inkjet Printing

Drop-on-demand (DOD) inkjet printing enables exact dispensing and positioning of single droplets in the picoliter range. In this study, we investigate the long-term reproducibility of droplet formation of piezoelectric inkjet printed drug solutions using solvents with different volatilities. We found inkjet printability of EtOH/ASA drug solutions is limited, as there is a rapid forming of drug deposits on the nozzle of the printhead because of fast solvent evaporation. Droplet formation of c = 100 g/L EtOH/ASA solution was affected after only a few seconds by little drug deposits, whereas for c = 10 g/L EtOH/ASA solution, a negative affection was observed only after t = 15 min, while prominent drug deposits form at the printhead tip. Due to the creeping effect, the crystallizing structures of ASA spread around the nozzle but do not clog it necessarily. When there is a negative affection, the droplet trajectory is affected the most, while the droplet volume and droplet velocity are influenced less. In contrast, no formation of drug deposits could be observed for highly concentrated, low volatile DMSO-based drug solution of c = 100 g/L even after a dispensing time of t = 30 min. Therefore, low volatile solvents are preferable to highly volatile solvents to ensure a reproducible droplet formation in long-term inkjet printing of highly concentrated drug solutions. Highly volatile solvents require relatively low drug concentrations and frequent printhead cleaning. The findings of this study are especially relevant when high droplet positioning precision is desired, e.g., drug loading of microreservoirs or drug-coating of microneedle devices.

Small-Scale Continuous Drug Product Manufacturing using Dropwise Additive Manufacturing and Three Phase Settling for Integration with Upstream Drug Substance Production

The pharmaceutical industry has traditionally relied on mass manufacturing to make its products. This has created multiple problems in the drug supply network, including long production times, inflexible and sluggish manufacturing and lack of personalized dosing. The industry is gradually adapting to these challenges and is developing novel technologies to address them. Continuous manufacturing and 3D printing are two promising techniques that can revolutionize pharmaceutical manufacturing. However, most research studies into these methods tend to treat them separately. This study seeks to develop a new processing route to continuously integrate a 3D printing platform (Drop-on-Demand, DoD, printing) with crystallization that is generally the final step of the active ingredient manufacturing. Accomplishing this integration would enable harnessing the benefits of each method- personalized dosing of 3D printing and flexibility and speed of continuous manufacturing. A novel unit operation, three-phase settling (TPS), is developed to integrate DoD with the upstream crystallizer. To ensure on-spec production of each printed dosage, two process analytical technology tools are incorporated in the printer to monitor drug loading in manufactured drug products in real time. Experimental demonstration of this system is carried out via two case studies: the first study uses an active ingredient celecoxib to test the standalone operation of TPS; the second study demonstrates the operation of the integrated system (crystallizer - TPS - DoD) to continuously make drug products for the active ingredient- lomustine. A dissolution test is also performed on the manufactured and commercial lomustine drug products to compare their dissolution behavior.

Reimagining Drug Manufacturing Paradigm in Today’s Pharmacy Landscape

The coronavirus disease 2019 pandemic has escalated the ongoing problem of critical medication shortages, which has serious implications for the health of our patients. Currently, active pharmaceutical ingredients (APIs) are synthesized in large-scale batch operations and shipped to drug product manufacturers, where they are produced on a large scale at centralized facilities. In the centralized drug manufacturing process, the formulation components, operations, and packaging are structured to favor long-term storage and shipment of resultant medicines to the point of care, making this process vulnerable to supply chain disruptions. We propose a rethinking of the drug manufacturing paradigm with an upgraded pharmaceutical compounding-based manufacturing paradigm. This paradigm will be based on integration of continuous manufacturing of APIs and manufacturing of medicines at the point of care with application of machine learning, artificial intelligence, and 3-dimensional printing. This paradigm will support implementation of precision medicine and customization according to patients’ needs. The new model of drug manufacturing will be less dependent on the supply chain while ensuring availability of medicines in a cost-effective manner.

Polymers in Technologies of Additive and Inkjet Printing of Dosage Formulations

Technologies for obtaining dosage formulations (DF) for personalized therapy are currently being developed in the field of inkjet (2D) and 3D printing, which allows for the creation of DF using various methods, depending on the properties of pharmaceutical substances and the desired therapeutic effect. By combining these types of printing with smart polymers and special technological approaches, so-called 4D printed dosage formulations are obtained. This article discusses the main technological aspects and used excipients of a polymeric nature for obtaining 2D, 3D, 4D printed dosage formulations. Based on the literature data, the most widely used polymers, their properties, and application features are determined, and the technological characteristics of inkjet and additive 3D printing are shown. Conclusions are drawn about the key areas of development and the difficulties that arise in the search and implementation in the production of new materials and technologies for obtaining those dosage formulations.

Binder jetting 3D printing of challenging medicines: from low dose tablets to hydrophobic molecules

Increasing access to additive manufacturing technologies utilising easily available desktop devices opened novel ways for formulation of personalized medicines. It is, however, challenging to propose a flexible and robust formulation platform which can be used for fabrication of tailored solid dosage forms composed of APIs with different properties (e.g., hydrophobicity) without extensive optimization. This manuscript presents a strategy for formulation of fast dissolving tablets using binder jetting (BJ) technology. The approach is demonstrated using two model APIs: hydrophilic quinapril hydrochloride (QHCl, logP = 1.4) and hydrophobic clotrimazole (CLO, logP = 5.4). The proposed printing method uses inexpensive well known and easily available FDA approved pharmaceutical excipients. The obtained model tablets had uniform content of the drug, excellent mechanical properties and highly porous structure resulting in short disintegration time and fast dissolution rate. The tablets could be scaled and obtained in predesigned shapes and sizes. The proposed method may find its application in the early stages of drug development where high flexibility of the formulation is required and the amount of available API is limited.

Polymers in pharmaceutical additive manufacturing: A balancing act between printability and product performance

Materials and manufacturing processes share a common purpose of enabling the pharmaceutical product to perform as intended. This review on the role of polymeric materials in additive manufacturing of oral dosage forms, focuses on the interface between the polymer and key stages of the additive manufacturing process, which determine printability. By systematically clarifying and comparing polymer functional roles and properties for a variety of AM technologies, together with current and emerging techniques to characterize these properties, suggestions are provided to stimulate the use of readily available and sometimes underutilized pharmaceutical polymers in additive manufacturing. We point to emerging characterization techniques and digital tools, which can be harnessed to manage existing trade-offs between the role of polymers in printer compatibility versus product performance. In a rapidly evolving technological space, this serves to trigger the continued development of 3D printers to suit a broader variety of polymers for widespread applications of pharmaceutical additive manufacturing.

Printing Methods in the Production of Orodispersible Films

Orodispersible film (ODF) formulations are promising and progressive drug delivery systems that are widely accepted by subjects across all the age groups. They are traditionally fabricated using the most popular yet conventional method called solvent casting method. The most modern and evolving method is based on printing technologies and such printed products are generally termed as printed orodispersible films (POFs). This modern technology is well suited to fabricate ODFs across different settings (laboratory or industrial) in general and in a pharmacy setting in particular. The present review provides an overview of various printing methods employed in fabricating POFs. Particularly, it provides insight about preparing POFs using inkjet, flexographic, and three-dimensional printing (3DP) or additive manufacturing techniques like filament deposition modeling, hot-melt ram extrusion 3DP, and semisolid extrusion 3DP methods. Additionally, the review is focused on patenting trends in POFs using ESPACENET, a European Patent Office search database. Finally, the review captures future market potential of 3DP in general and ODFs market potential in particular.

[2D-3D printing in hospital pharmacies, what roles and challenges?]

The additive technology or 2D and 3D printing are increasingly used in various industrial fields, from aeronautics to mechanics but also in the fields of health such as dentistry or for bone reconstructions. These techniques have been studied for about fifteen years by the academic community in the pharmaceutical field (medical device and drug), and recently they have started to be applied to produce drugs in industry and in hospitals. Indeed, the Food and Drug Administration approved in August 2015 the marketing of the first drug printed by additive technique, then in 2018 the first clinical trial using 3D printed drugs was carried out in Great Britain by a hospital pharmacy. 2D-3D printing is presented as one of the tools of a more personalized medicine, the techniques of additive printing allowing the production of tabs containing several drugs in one tab (polypills) and the development of custom modified-releases drugs. This approach could allow better acceptance of the finished product and secure manufacturing. The objective of this work is to highlight relevant printing technologies for implementation in hospital pharmacies, and to see how these technologies could lead to a change in pharmaceutical practices, to improve patient care.

Water-based 3D inkjet printing of an oral pharmaceutical dosage form

Inkjet printing is a form of additive manufacturing where liquid droplets are selectively deposited onto a substrate followed by solidification. The process provides significant potential advantages for producing solid oral dosage forms or tablets, including a reduction in the number of manufacturing steps as well as the ability to tailor a unique dosage regime to an individual patient. This study utilises solvent inkjet printing to print tablets through the use of a Fujifilm Dimatix printer. Using polyvinylpyrrolidone and thiamine hydrochloride (a model excipient and drug, respectively), a water-based ink formulation was developed to exhibit reliable and effective jetting properties. Tablets were printed on polyethylene terephthalate films where solvent evaporation in the ambient environment was the solidification mechanism. The tablets were shown to contain a drug loading commensurate with the composition of the ink, in its preferred polymorphic phase of a non-stoichiometric hydrate distributed homogenously. The printed tablets displayed rapid drug release. This paper illustrates solvent inkjet printing's ability to print entire free-standing tablets without an edible substrate being part of the tablet and the use of additional printing methods. Common problems with solvent-based inkjet printing, such as the use toxic solvents, are avoided. The strategy developed here for tablet manufacturing from a suitable ink is general and provides a framework for the formulation for any drug that is soluble in water.

Manufacturing of Multi-drug Formulations with Customised Dose by Solvent Impregnation of Mesoporous Silica Tablets

The manufacture of personalised medicines where specific combinations of active pharmaceutical ingredients (APIs) and their dose within a tablet would be adjusted to the needs of individual patients, would require new manufacturing approaches compared to the established practice. In the case of low-dose formulations, the required precision of API content might not be achievable by traditional unit operations such as solid powder blending. The aim of the present work was to explore an alternative approach, based on the concept of pre-formulated placebo tablets containing mesoporous silica particles capable of absorbing APIs in the form of solutions, which can be precisely dosed at arbitrarily low quantities. The precision of the liquid dosing system has been validated; it was shown that the mechanical properties of the tablets were satisfactory even after multiple impregnation-drying cycles and that pharmacopoeia specifications on content uniformity could be met. Using model APIs, the spatial distribution of the API within the tablet after impregnation was investigated and shown to depend on the number and order of the impregnation-drying cycles. It was found that when an API was loaded to the tablet in a single step, a different dissolution profile was obtained compared to the same quantity dosed in multiple smaller steps. Overall, the approach of loading multiple API to a pre-formulated tablet at defined quantities using drop-on-demand liquid dosing was found to be feasible from the dose uniformity point of view. Further research should focus on potential API interactions and storage stability of tablets manufactured in this way.

Dropwise Additive Manufacturing of Pharmaceutical Products Using Particle Suspensions

The principal method of drug delivery is by oral solid doses, the production of which often necessitates multiple post-crystallization unit operations to ensure content uniformity or enhance bioavailability. As an alternative to conventional dose production methods, applications of additive manufacturing technologies based on solvent- or melt-based formulations have demonstrated the potential for improvements to process efficiency, flexibility, and dosing precision. Here we explore the use of particulate suspensions in a dropwise additive manufacturing process as a method for dosing active ingredients in crystalline form, which may be difficult to achieve via powder processing due to poor flow properties. By employing a fluid-based method, powder flow issues are alleviated and adaptation of the process to new particles/crystals is facilitated by dimensional analysis. In this work, a feasibility study was conducted using 4 active ingredient powders, each with non-ideal particle properties, and 2 carrier fluids, in which the active ingredient does not dissolve, to formulate suspensions for dose manufacturing; drug products were analyzed to show reproducibility of dosing and to assess preservation of particle size through the process. Performance across particle types is affected by particle size and shape, and is related through effects on the rheological properties of the formulation.

Analytical aspects of printed oral dosage forms

Printing technologies, both 2D and 3D, have gained considerable interest during the last years for manufacturing of personalized dosage forms, tailored to each patient. Here we review the research work on 2D printing techniques, mainly inkjet printing, for manufacturing of film-based oral dosage forms. We describe the different printing techniques and give an overview of film-based oral dosage forms produced using them. The main part of the review focuses on the non-destructive analytical methods used for evaluation of qualitative aspects of printed dosage forms, e.g., solid-state properties, as well as for quantification of the active pharmaceutical ingredient (API) in the printed dosage forms, with an emphasis on spectroscopic methods. Finally, the authors share their view on the future of printed dosage forms.

Inkjet printing of paracetamol and indomethacin using electromagnetic technology: Rheological compatibility and polymorphic selectivity

Drop-on-demand inkjet printing is a potential enabling technology both for continuous manufacturing of pharmaceuticals and for personalized medicine, but its use is often restricted to low-viscosity solutions and nano-suspensions. In the present study, a robust electromagnetic (valvejet) inkjet technology has been successfully applied to deposit prototype dosage forms from solutions with a wide range of viscosities, and from suspensions with particle sizes exceeding 2 μm. A detailed solid-state study of paracetamol, printed from a solution ink on hydroxypropyl methylcellulose (HPMC), revealed that the morphology of the substrate and its chemical interactions can have a considerable influence on polymorphic selectivity. Paracetamol ink crystallized exclusively into form II when printed on a smooth polyethylene terephthalate substrate, and exclusively into form I when in sufficient proximity to the rough surface of the HPMC substrate to be influenced by confinement in pores and chemical interactions. The relative standard deviation in the strength of the dosage forms was <4% in all cases, for doses as low as 0.8 mg, demonstrating the accuracy and reproducibility associated with electromagnetic inkjet technology. Good adhesion of indomethacin on HPMC was achieved using a suspension ink with hydroxypropyl cellulose, but not on an alternative polyethylene terephthalate substrate, emphasising the need to tailor the binder to the substrate. Future work will focus on lower-dose drugs, for which dosing flexibility and fixed dose combinations are of particular interest.

Alternative Manufacturing Concepts for Solid Oral Dosage Forms From Drug Nanosuspensions Using Fluid Dispensing and Forced Drying Technology

Flexible manufacturing technologies for solid oral dosage forms with a continuous adjustability of the manufactured dose strength are of interest for applications in personalized medicine. This study explored the feasibility of using microvalve technology for the manufacturing of different solid oral dosage form concepts. Hard gelatin capsules filled with excipients, placebo tablets, and polymer films, placed in hard gelatin capsules after drying, were considered as substrates. For each concept, a basic understanding of relevant formulation parameters and their impact on dissolution behavior has been established. Suitable matrix formers, present either on the substrate or directly in the drug nanosuspension, proved to be essential to prevent nanoparticle agglomeration of the drug nanoparticles and to ensure a fast dissolution behavior. Furthermore, convection and radiation drying methods were investigated for the fast drying of drug nanosuspensions dispensed onto polymer films, which were then placed in hard gelatin capsules. Changes in morphology and in drug and matrix former distribution were observed for increasing drying intensity. However, even fast drying times below 1 min could be realized, while maintaining the nanoparticulate drug structure and a good dissolution behavior.

Orodispersible films: Towards drug delivery in special populations

Orodispersible films (ODF) hold promise as a novel delivery method, with the potential to deliver tailored therapies to different patient populations. This article reviews the current strides of ODF technology and some of its unmet quality and manufacturing aspects. A topic highlights opportunities and limitations of inkjet printed ODF as a population-specific drug delivery. Overall, this article aims to stimulate further research to fill the current knowledge gap between manufacturing and administration requirements of ODF targeting specific patient subpopulations such as geriatrics.

Impact of Formulation Properties and Process Parameters on the Dispensing and Depositioning of Drug Nanosuspensions Using Micro-Valve Technology

Flexible manufacturing processes with continuously adjustable dose strengths are considered particularly innovative and interesting for applications in personalized medicine, continuous manufacturing, or early drug development. A piezo-actuated micro-valve has been investigated for the dispensing and depositioning of drug nanosuspensions onto substrates to facilitate the manufacturing of solid oral dosage forms. The investigated micro-valve has been characterized regarding dispensing behavior, mass flow, accuracy, and robustness. The amount of dispensed drug compound during 1 dispensing event could be continuously adjusted from a few micrograms to several milligrams with high accuracy. Fluid properties, dispensing parameters of the micro-valve, and the resulting steady state mass flow could be correlated adequately for low-viscous drug nanosuspensions. High-speed imaging was used to investigate the dispensing behavior of the micro-valve regarding the evolution of the dispensed drug nanosuspension after ejection from the nozzle and the behavior during impact on flat and dry solid substrates. The experimentally determined breakup length of the dispensed liquid jet could be correlated with a semiempirical equation. From image sequences of the jet impact, We-Re phase diagrams could be established, providing a profound understanding and systematic guidance for the controlled depositioning of the entire dispensed drug nanosuspension onto the substrate.

A new chapter in pharmaceutical manufacturing: 3D-printed drug products

FDA recently approved a 3D-printed drug product in August 2015, which is indicative of a new chapter for pharmaceutical manufacturing. This review article summarizes progress with 3D printed drug products and discusses process development for solid oral dosage forms. 3D printing is a layer-by-layer process capable of producing 3D drug products from digital designs. Traditional pharmaceutical processes, such as tablet compression, have been used for decades with established regulatory pathways. These processes are well understood, but antiquated in terms of process capability and manufacturing flexibility. 3D printing, as a platform technology, has competitive advantages for complex products, personalized products, and products made on-demand. These advantages create opportunities for improving the safety, efficacy, and accessibility of medicines. Although 3D printing differs from traditional manufacturing processes for solid oral dosage forms, risk-based process development is feasible. This review highlights how product and process understanding can facilitate the development of a control strategy for different 3D printing methods. Overall, the authors believe that the recent approval of a 3D printed drug product will stimulate continual innovation in pharmaceutical manufacturing technology. FDA encourages the development of advanced manufacturing technologies, including 3D-printing, using science- and risk-based approaches.

Social aspects in additive manufacturing of pharmaceutical products

INTRODUCTION

Additive manufacturing (AM) techniques, such as drug printing, represent a new engineering approach that can implement the concept of personalized medicine via on-demand manufacturing of dosage forms with individually adjusted doses. Implementation of AM principles, such as pharmacoprinting, will challenge the entire drug distribution chain and affect the society at different levels. Areas covered: This work summarizes the concept of personalized medicine and gives an overview of possibilities for monitoring patients' health. The most recent activities in the field of printing technologies for fabrication of dosage forms and 'polypills' with flexible doses and tailored release profiles are reviewed. Different scenarios for the drug distribution chain with the required adjustments in drug logistics, quality systems and environmental safety are discussed, as well as whether AM will be used for production of on-demand medicine. The impact of such changes in the distribution chain on regulation, healthcare professionals and patients are highlighted. Expert opinion: Drug manufacturing by traditional methods is well-established, but it lacks the possibility for on-demand personalized drug production. With the recent approval of the first printed medicine, society should be prepared for the changes that will follow the introduction of printed pharmaceuticals.

Recent developments in micro- and nanofabrication techniques for the preparation of amorphous pharmaceutical dosage forms

Nano- and microfabrication techniques have been widely explored in the textile, polymer and biomedical arenas, although more recently these systems have attracted considerable interest as drug delivery vehicles with concomitant considerations of physical characterization, scalability, stability and drug release. In this review, the current thinking with regards to the manufacture of solid amorphous pharmaceutical materials using electrohydrodynamic and gyration-based approaches, melt-spinning approaches, thermal moulding, inkjet printing and 3D printing will be examined in the context of their potential and actual viability as dosage forms. A series of practical examples will be discussed as to how these approaches have been used as means of producing drug delivery systems for a range of delivery systems and treatments.

Drop-on-Demand System for Manufacturing of Melt-based Solid Oral Dosage: Effect of Critical Process Parameters on Product Quality

The features of a drop-on-demand-based system developed for the manufacture of melt-based pharmaceuticals have been previously reported. In this paper, a supervisory control system, which is designed to ensure reproducible production of high quality of melt-based solid oral dosages, is presented. This control system enables the production of individual dosage forms with the desired critical quality attributes: amount of active ingredient and drug morphology by monitoring and controlling critical process parameters, such as drop size and product and process temperatures. The effects of these process parameters on the final product quality are investigated, and the properties of the produced dosage forms characterized using various techniques, such as Raman spectroscopy, optical microscopy, and dissolution testing. A crystallization temperature control strategy, including controlled temperature cycles, is presented to tailor the crystallization behavior of drug deposits and to achieve consistent drug morphology. This control strategy can be used to achieve the desired bioavailability of the drug by mitigating variations in the dissolution profiles. The supervisor control strategy enables the application of the drop-on-demand system to the production of individualized dosage required for personalized drug regimens.

Inkjet printing for pharmaceutics - A review of research and manufacturing

Global regulatory, manufacturing and consumer trends are driving a need for change in current pharmaceutical sector business models, with a specific focus on the inherently expensive research costs, high-risk capital-intensive scale-up and the traditional centralised batch manufacturing paradigm. New technologies, such as inkjet printing, are being explored to radically transform pharmaceutical production processing and the end-to-end supply chain. This review provides a brief summary of inkjet printing technologies and their current applications in manufacturing before examining the business context driving the exploration of inkjet printing in the pharmaceutical sector. We then examine the trends reported in the literature for pharmaceutical printing, followed by the scientific considerations and challenges facing the adoption of this technology. We demonstrate that research activities are highly diverse, targeting a broad range of pharmaceutical types and printing systems. To mitigate this complexity we show that by categorising findings in terms of targeted business models and Active Pharmaceutical Ingredient (API) chemistry we have a more coherent approach to comparing research findings and can drive efficient translation of a chosen drug to inkjet manufacturing.

Personalised dosing: Printing a dose of one's own medicine

Ink-jet printing is a versatile, precise and relatively inexpensive method of depositing small volumes of solutions with remarkable accuracy and repeatability. Although developed primarily as a technology for image reproduction, its areas of application have expanded significantly in recent years. It is particularly suited to the manufacture of low dose medicines or to short production runs and so offers a potential manufacturing solution for the paradigm of personalised medicines. This review discusses the technical and clinical aspects of ink-jet printing that must be considered in order for the technology to become widely adopted in the pharmaceutical arena and considers applications in the literature.