3D printing in pharmaceutics: A new tool for designing customized drug delivery systems

The potential of three-dimensional printing for pediatric oral solid dosage forms

Pediatric patients often require individualized dosing of medicine due to their unique pharmacokinetic and developmental characteristics. Current methods for tailoring the dose of pediatric medications, such as tablet splitting or compounding liquid formulations, have limitations in terms of dosing accuracy and palatability. This paper explores the potential of 3D printing as a solution to address the challenges and provide tailored doses of medication for each pediatric patient. The technological overview of 3D printing is discussed, highlighting various 3D printing technologies and their suitability for pharmaceutical applications. Several individualization options with the potential to improve adherence are discussed, such as individualized dosage, custom release kinetics, tablet shape, and palatability. To integrate the preparation of 3D printed medication at the point of care, a decentralized manufacturing model is proposed. In this setup, pharmaceutical companies would routinely provide materials and instructions for 3D printing, while specialized compounding centers or hospital pharmacies perform the printing of medication. In addition, clinical opportunities of 3D printing for dose-finding trials are emphasized. On the other hand, current challenges in adequate dosing, regulatory compliance, adherence to quality standards, and maintenance of intellectual property need to be addressed for 3D printing to close the gap in personalized oral medication.

Automated Non-Sterile Pharmacy Compounding: A Multi-Site Study in European Hospital and Community Pharmacies with Pediatric Immediate Release Propranolol Hydrochloride Tablets

Pharmacy compounding, the art and science of preparing customized medications to meet individual patient needs, is on the verge of transformation. Traditional methods of compounding often involve manual and time-consuming processes, presenting challenges in terms of consistency, dosage accuracy, quality control, contamination, and scalability. However, the emergence of cutting-edge technologies has paved a way for a new era for pharmacy compounding, promising to redefine the way medications are prepared and delivered as pharmacy-tailored personalized medicines. In this multi-site study, more than 30 hospitals and community pharmacies from eight countries in Europe utilized a novel automated dosing approach inspired by 3D printing for the compounding of non-sterile propranolol hydrochloride tablets. CuraBlend® excipient base, a GMP-manufactured excipient base (pharma-ink) intended for automated compounding applications, was used. A standardized study protocol to test the automated dosing of tablets with variable weights was performed in all participating pharmacies in four different iterative phases. Integrated quality control was performed with an in-process scale and NIR spectroscopy supported by HPLC content uniformity measurements. In total, 6088 propranolol tablets were produced at different locations during this study. It was shown that the dosing accuracy of the process increased from about 90% to 100% from Phase 1 to Phase 4 by making improvements to the formulation and the hardware solutions. The results indicate that through this automated and quality controlled compounding approach, extemporaneous pharmacy manufacturing can take a giant leap forward towards automation and digital manufacture of dosage forms in hospital pharmacies and compounding pharmacies.

4D hydrogels: fabrication strategies, stimulation mechanisms, and biomedical applications

Shape-morphing hydrogels have emerged as a promising biomaterial due to their ability to mimic the anisotropic tissue composition by creating a gradient in local swelling behavior. In this case, shape deformations occur due to the non-uniform distribution of internal stresses, asymmetrical swelling, and shrinking of different parts of the same hydrogel. Herein, we discuss the four-dimensional (4D) fabrication techniques (extrusion-based printing, dynamic light processing, and solvent casting) employed to prepare shape-shifting hydrogels. The important distinction between mono- and dual-component hydrogel systems, the capabilities of 3D constructs to undergo uni- and bi-directional shape changes, and the advantages of composite hydrogels compared to their pristine counterparts are presented. Subsequently, various types of actuators such as moisture, light, temperature, pH, and magnetic field and their role in achieving the desired and pre-determined shapes are discussed. These 4D gels have shown remarkable potential as programmable scaffolds for tissue regeneration and drug-delivery systems. Finally, we present futuristic insights into integrating piezoelectric biopolymers and sensors to harvest mechanical energy from motions during shape transformations to develop self-powered biodevices.

3D printing processes in precise drug delivery for personalized medicine

With the advent of personalized medicine, the drug delivery system will be changed significantly. The development of personalized medicine needs the support of many technologies, among which three-dimensional printing (3DP) technology is a novel formulation-preparing process that creates 3D objects by depositing printing materials layer-by-layer based on the computer-aided design method. Compared with traditional pharmaceutical processes, 3DP produces complex drug combinations, personalized dosage, and flexible shape and structure of dosage forms (DFs) on demand. In the future, personalized 3DP drugs may supplement and even replace their traditional counterpart. We systematically introduce the applications of 3DP technologies in the pharmaceutical industry and summarize the virtues and shortcomings of each technique. The release behaviors and control mechanisms of the pharmaceutical DFs with desired structures are also analyzed. Finally, the benefits, challenges, and prospects of 3DP technology to the pharmaceutical industry are discussed.

Medical, pharmaceutical, and nutritional applications of 3D-printing technology in diabetes

AIMS

Despite numerous studies covering the various features of three-dimensional printing (3D printing) technology, and its applications in food science and disease treatment, no study has yet been conducted to investigate applying 3D printing in diabetes. Therefore, the present study centers on the utilization and impact of 3D printing technology in relation to the nutritional, pharmaceutical, and medicinal facets of diabetes management. It highlights the latest advancements, and challenges in this field.

METHODS

In this review, the articles focusing on the application and effect of 3D printing technology on medical, pharmaceutical, and nutritional aspects of diabetes management were collected from different databases.

RESULT

High precision of 3D printing in the placement of cells led to accurate anatomic control, and the possibility of bio-printing pancreas and β-cells. Transdermal drug delivery via 3D-printed microneedle (MN) patches was beneficial for the management of diabetes disease. 3D printing supported personalized medicine for Diabetes Mellitus (DM). For instance, it made it possible for pharmaceutical companies to manufacture unique doses of medications for every diabetic patient. Moreover, 3D printing allowed the food industry to produce high-fiber and sugar-free products for the individuals with DM.

CONCLUSIONS

In summary, applying 3D printing technology for diabetes management is in its early stages, and needs to be matured and developed to be safely used for humans. However, its rapid progress in recent years showed a bright future for the treatment of diabetes.

Fabrication of 3D-printed scaffolds loaded with gallium acetylacetonate for potential application in osteoclastic bone resorption

We recently reported the potential of a new gallium compound, gallium acetylacetonate (GaAcAc) in combating osteoclastic bone resorption through inhibition of osteoclast differentiation and function. Herein, we focused on 3D-printed polylactic acid scaffolds that were loaded with GaAcAc and investigated the impact of scaffold pretreatment with polydopamine (PDA) or sodium hydroxide (NaOH). We observed a remarkable increase in scaffold hydrophilicity with PDA or NaOH pretreatment while biocompatibility and in vitro degradation were not affected. NaOH-pretreated scaffolds showed the highest amount of GaAcAc loading when compared to other scaffolds (p < 0.05). NaOH-pretreated scaffolds with GaAcAc loading showed effective reduction of osteoclast counts and size. The trend was supported by suppression of key osteoclast differentiation markers such as NFAT2, c-Fos, TRAF6, & TRAP. All GaAcAc-loaded scaffolds, regardless of surface pretreatment, were effective in inhibiting osteoclast function as evidenced by reduction in the number of resorptive pits in bovine cortical bone slices (p < 0.01). The suppression of osteoclast function according to the type of scaffold followed the ranking: GaAcAc loading without surface pretreatment > GaAcAc loading with NaOH pretreatment > GaAcAc loading with PDA pretreatment. Additional studies will be needed to fully elucidate the impact of surface pretreatment on the efficacy and safety of GaAcAc-loaded 3D-printed scaffolds.

Design and fabrication of customizable microneedles enabled by 3D printing for biomedical applications

Microneedles (MNs) is an emerging technology that employs needles ranging from 10 to 1000 μm in height, as a minimally invasive technique for various procedures such as therapeutics, disease monitoring and diagnostics. The commonly used method of fabrication, micromolding, has the advantage of scalability, however, micromolding is unable to achieve rapid customizability in dimensions, geometries and architectures, which are the pivotal factors determining the functionality and efficacy of the MNs. 3D printing offers a promising alternative by enabling MN fabrication with high dimensional accuracy required for precise applications, leading to improved performance. Furthermore, enabled by its customizability and one-step process, there is propitious potential for growth for 3D-printed MNs especially in the field of personalized and on-demand medical devices. This review provides an overview of considerations for the key parameters in designing MNs, an introduction on the various 3D-printing techniques for fabricating this new generation of MNs, as well as highlighting the advancements in biomedical applications facilitated by 3D-printed MNs. Lastly, we offer some insights into the future prospects of 3D-printed MNs, specifically its progress towards translation and entry into market.

Fixed-Dose Combination Formulations in Solid Oral Drug Therapy: Advantages, Limitations, and Design Features

Whilst monotherapy is traditionally the preferred treatment starting point for chronic conditions such as hypertension and diabetes, other diseases require the use of multiple drugs (polytherapy) from the onset of treatment (e.g., human immunodeficiency virus acquired immunodeficiency syndrome, tuberculosis, and malaria). Successful treatment of these chronic conditions is sometimes hampered by patient non-adherence to polytherapy. The options available for polytherapy are either the sequential addition of individual drug products to deliver an effective multi-drug regimen or the use of a single fixed-dose combination (FDC) therapy product. This article intends to critically review the use of FDC drug therapy and provide an insight into FDC products which are already commercially available. Shortcomings of FDC formulations are discussed from multiple perspectives and research gaps are identified. Moreover, an overview of fundamental formulation considerations is provided to aid formulation scientists in the design and development of new FDC products.

Three-Dimensional-Printed Sodium Alginate and k-Carrageenan-Based Scaffolds with Potential Biomedical Applications

This work reports the development of a marine-derived polysaccharide formulation based on k-Carrageenan and sodium alginate in order to produce a novel scaffold for engineering applications. The viscoelastic properties of the bicomponent inks were assessed via rheological tests prior to 3D printing. Compositions with different weight ratios between the two polymers, without any crosslinker, were subjected to 3D printing for the first time, to the best of our knowledge, and the fabrication parameters were optimized to ensure a controlled architecture. Crosslinking of the 3D-printed scaffolds was performed in the presence of a chloride mixture (CaCl2:KCl = 1:1; v/v) of different concentrations. The efficiency of the crosslinking protocol was evaluated in terms of swelling behavior and mechanical properties. The swelling behavior indicated a decrease in the swelling degree when the concentration of the crosslinking agent was increased. These results are consistent with the nanoindentation measurements and the results of the macro-scale tests. Moreover, morphology analysis was also used to determine the pore size of the samples upon freeze-drying and the uniformity and micro-architectural characteristics of the scaffolds. Overall, the registered results indicated that the bicomponent ink, Alg/kCG = 1:1 may exhibit potential for tissue-engineering applications.

3D printing in vaginal drug delivery: a revolution in pharmaceutical manufacturing

INTRODUCTION

The Food and Drug Administration's approval of the first three-dimensional (3D) printed tablet, Spritam®, led to a burgeoning interest in using 3D printing to fabricate numerous drug delivery systems for different routes of administration. The high degree of manufacturing flexibility achieved through 3D printing facilitates the preparation of dosage forms with many actives with complex and tailored release profiles that can address individual patient needs.

AREAS COVERED

This comprehensive review provides an in-depth look into the several 3D printing technologies currently utilized in pharmaceutical research. Additionally, the review delves into vaginal anatomy and physiology, 3D-printed drug delivery systems for vaginal applications, the latest research studies, and the challenges of 3D printing technology and future possibilities.

EXPERT OPINION

3D printing technology can produce drug-delivery devices or implants optimized for vaginal applications, including vaginal rings, intra-vaginal inserts, or biodegradable microdevices loaded with drugs, all custom-tailored to deliver specific medications with controlled release profiles. However, though the potential of 3D printing in vaginal drug delivery is promising, there are still challenges and regulatory hurdles to overcome before these technologies can be widely adopted and approved for clinical use. Extensive research and testing are necessary to ensure safety, effectiveness, and biocompatibility.

Unraveling the influence of solvent composition on Drop-on-Demand binder jet 3D printed tablets containing calcium sulfate hemihydrate

Recently, binder jet printed modular tablets were loaded with three anti-viral drugs via Drop on Demand (DoD) technology where drug solutions prepared in ethanol showed faster release than those prepared in water. During printing, water is used as a binding agent, whereas ethanol is added to maintain the porous structure of the tablets. Thus, the hypothesis is that the porosity would be controlled by manipulating the percentage of water and ethanol. In this study, Rhodamine 6G (R6G) was selected as a model drug due to its high solubility in water and ethanol, visualization function as a fluorescent dye, and potential therapeutic effects for cancer treatment. Approximately, 10 mg/ml R6G solutions were prepared with five different water-ethanol ratios (0-100, 75-25, 50-50, 75-25, 100-0). The ink solutions were printed onto blank binder jet 3D-printed tablets containing calcium sulphate hemihydrate using DoD technology. The tablets were dried at room temperature and then characterized using SEM-EDX, fluorescent microscope, TGA, XRD, FTIR, and DSC as well as in vitro release studies to investigate the impact of water-ethanol ratio on the release profile of R6G. Results indicated that the solution with higher ethanol ratio penetrated the tablets faster than the lower ethanol ratio, while the solution prepared with pure water was first accumulated onto the tablets' surface and then absorbed by the tablets. Moreover, tablets with more water content gained more weight and thickness. The EDX analysis and fluorescent microscope showed the uniform surface distribution of the drug. The SEM images revealed the difference in the tablet surface among the five formulations. Furthermore, the TGA data presents a notable increase in water loss, with XRD analysis suggesting the formation of gypsum in tablets containing elevated water content. The release study exhibited that the fastest release was from WE0-100, whereas the release rate decreases as the content of water increases. The WE0-100 releases more than 40 % drug within the first hour which is almost twice as high of the WE100-0 formulation. This DoD technology could distribute drugs onto the tablet's surface uniformly. The calcium sulfate would transform from hemihydrate to dihydrate form in the presence of water and therefore, those tablets treated with higher water content led to slower release. In conclusion, this study underscores the substantial impact of the water-ethanol ratio on drug release from binder jet printed tablets and highlights the potential of DoD technology for uniform drug distribution and controlled release.

Coated Porous Microneedles for Effective Intradermal Immunization with Split Influenza Vaccine

In order to alleviate the pain associated with subcutaneous injections, microneedles (MNs) are gaining increasing attention as a novel transdermal drug delivery modality. Among them, porous microneedles (pMNs) are particularly suitable for the delivery of drugs and vaccines whose activity is sensitive to the microneedle preparation process. They can carry drugs actively to achieve an effective load and deliver drugs into the skin. In this study, the biocompatible cellulose acetate (CA) microporous MNs with a large pore size of 1.13 μm ± 0.45 and a high porosity of 74.8% ± 2.8% were prepared by using a safe nonsolvent-induced phase separation (NIPS) method. The MN patches prepared after adsorption of appropriate concentrations of split influenza vaccine fully met the dose loading requirements. A biocompatible carboxymethyl cellulose (CMC) solution was used in the pMN coating to strengthen their mechanical properties, with an average maximum stress of 32.89 N, and to act as a medium for the dispersion of an adjuvant in the coating layer. The influenza vaccine adsorbed in the micropore and the adjuvant dispersed in the coating were released intradermally to exert synergistic effects with different release patterns and rates. The coated pMNs induced an efficient immune response in Wistar rats with a hemagglutination inhibition (HI) titer of ≥1024, which was comparable to that of intramuscular injection. The research is organized around the goal of engineering exploration of innovative technologies, suggesting that pMNs have a tantalizing prospect for future applications. It opens up the possibility of eventually obtaining a simple, easy-to-use, and efficient application technology for the prevention of global epidemics like influenza.

Implantable magnetically-actuated capsule for on-demand delivery

Many implantable drug delivery systems (IDDS) have been developed for long-term, pulsatile drug release. However, they are often limited by bulky size, complex electronic components, unpredictable drug delivery, as well as the need for battery replacement and consequent replacement surgery. Here, we develop an implantable magnetically-actuated capsule (IMAC) and its portable magnetic actuator (MA) for on-demand and robust drug delivery in a tether-free and battery-free manner. IMAC utilizes the bistable mechanism of two magnetic balls inside IMAC to trigger drug delivery under a strong magnetic field (|Ba| > 90 mT), ensuring precise and reproducible drug delivery (9.9 ± 0.17 μg per actuation, maximum actuation number: 180) and excellent anti-magnetic capability (critical trigger field intensity: ∼90 mT). IMAC as a tetherless robot can navigate to and anchor at the lesion sites driven by a gradient magnetic field (∇ Bg = 3 T/m, |Bg| < 60 mT), and on-demand release drug actuated by a uniform magnetic field (|Ba| = ∼100 mT) within the gastrointestinal tract. During a 15-day insulin administration in vivo, the diabetic rats treated with IMAC exhibited highly similar pharmacokinetic and pharmacodynamic profiles to those administrated via subcutaneous injection, demonstrating its robust and on-demand drug release performance. Moreover, IMAC is biocompatible, batter-free, refillable, miniature (only Φ 6.3 × 12.3 mm3), and lightweight (just 0.8 g), making it an ideal alternative for precise implantable drug delivery and friendly patient-centered drug administration.

Reverse Engineering and 3D Printing of Medical Devices for Drug Delivery and Drug-Embedded Anatomic Implants

In recent years, 3D printing (3DP) has advanced traditional medical treatments. This review explores the fusion of reverse engineering and 3D printing of medical implants, with a specific focus on drug delivery applications. The potential for 3D printing technology to create patient-specific implants and intricate anatomical models is discussed, along with its ability to address challenges in medical treatment. The article summarizes the current landscape, challenges, benefits, and emerging trends of using 3D-printed formulations for medical implantation and drug delivery purposes.

Two-dimensional printing of nanoparticles as a promising therapeutic method for personalized drug administration

The necessity for personalized patient treatment has drastically increased since the contribution of genes to the differences in physiological and metabolic state of individuals have been exposed. Different approaches have been considered so far in order to satisfy all of the diversities in patient needs, yet none of them have been fully implemented thus far. In this framework, various types of 2D printing technologies have been identified to offer some potential solutions for personalized medication, which development is increasing rapidly. Accurate drug-on-demand deposition, the possibility of consuming multiple drug substances in one product and adjusting individual drug concentration are just some of the few benefits over existing bulk pharmaceuticals manufacture, which printing technologies brings. With inclusion of nanotechnology by printing nanoparticles from its dispersions some further opportunities such as controlled and stimuli-responsive drug release or targeted and dose depending on drug delivery were highlighted. Yet, there are still some challenges to be solved before such products can reach the pharmaceutical market. In those terms mostly chemical, physical as well as microbiological stability concerns should be answered, with which 2D printing technology could meet the treatment needs of every individual and fulfill some existing drawbacks of large-scale batch production of pharmaceuticals we possess today.

A Bibliometric Analysis of 3D Printing in Personalized Medicine Research from 2012 to 2022

In recent years, the 3D printing of personalized drug formulations has attracted the attention of medical practitioners and academics. However, there is a lack of data-based analyses on the hotspots and trends of research in this field. Therefore, in this study, we performed a bibliometric analysis to summarize the 3D printing research in the field of personalized drug formulation from 2012 to 2022. This study was based on the Web of Science Core Collection Database, and a total of 442 eligible publications were screened. Using VOSviewer and online websites for bibliometric analysis and scientific mapping, it was observed that annual publications have shown a significant growth trend over the last decade. The United Kingdom and the United States, which account for 45.5% of the total number of publications, are the main drivers of this field. The International Journal of Pharmaceutics and University College London are the most prolific and cited journals and institutions. The researchers with the most contributions are Basit, Abdul W. and Goyanes Alvaro. The keyword analysis concluded that the current research hotspots are "drug release" and "drug dosage forms". In conclusion, 3D printing has broad application prospects in the field of personalized drugs, which will bring the pharmaceutical industry into a new era of innovation.

Evaluating 3D-printed bioseparation structures using multi-length scale tomography

X-ray computed tomography was applied in imaging 3D-printed gyroids used for bioseparation in order to visualize and characterize structures from the entire geometry down to individual nanopores. Methacrylate prints were fabricated with feature sizes of 500 µm, 300 µm, and 200 µm, with the material phase exhibiting a porous substructure in all cases. Two X-ray scanners achieved pixel sizes from 5 µm to 16 nm to produce digital representations of samples across multiple length scales as the basis for geometric analysis and flow simulation. At the gyroid scale, imaged samples were visually compared to the original computed-aided designs to analyze printing fidelity across all feature sizes. An individual 500 µm feature, part of the overall gyroid structure, was compared and overlaid between design and imaged volumes, identifying individual printed layers. Internal subvolumes of all feature sizes were segmented into material and void phases for permeable flow analysis. Small pieces of 3D-printed material were optimized for nanotomographic imaging at a pixel size of 63 nm, with all three gyroid samples exhibiting similar geometric characteristics when measured. An average porosity of 45% was obtained that was within the expected design range, and a tortuosity factor of 2.52 was measured. Applying a voidage network map enabled the size, location, and connectivity of pores to be identified, obtaining an average pore size of 793 nm. Using Avizo XLAB at a bulk diffusivity of 7.00 × 10-11 m2s-1 resulted in a simulated material diffusivity of 2.17 × 10-11 m2s-1 ± 0.16 × 10-11 m2s-1.

Fused Deposition Modelling 3D-Printed Gastro-Retentive Floating Device for Propranolol Hcl Tablets

Three-dimensional printing has revolutionized drug manufacturing and has provided a solution to the limitations associated with the conventional manufacturing method by designing complex drug delivery systems with customized drug release profiles for personalized therapies. The present investigation aims to design a gastric floating tablet with prolonged gastric floating time and sustained drug release profile. In the present study, a gastro retentive floating device (GRFD) was designed and fabricated using a fused deposition modelling (FDM)-based 3D printing technique. This device acts as a multifunctional dosage form exhibiting prolonged gastric retention time and sustained drug release profile with improved oral bioavailability in the upper gastrointestinal tract. Commercial polyvinyl alcohol (PVA) and polylactic acid (PLA) filaments were used to design GRFD, which was comprised of dual compartments. The outer sealed compartment acts as an air-filled chamber that imparts buoyancy to the device and the inner compartment is filled with a commercial propranolol hydrochloride immediate-release tablet. The device is designed as a round-shaped shell with a central opening of varying size (1 mm, 2 mm, 3 mm, and 4 mm), which acts as a drug release window. Scanning electron microscope (SEM) images were used to determine morphological characterization. The in vitro buoyancy and drug release were evaluated using the USP type II dissolution apparatus. All the designed GRFDs exhibit good floating ability and sustained drug release profiles. GRFDs fabricated using PLA filament show maximum buoyancy (>24 h) and sustained drug release for up to 10 h. The floating ability and drug release from the developed devices were governed by the drug release window opening size and the filament material affinity towards the gastric fluid. The designed GRFDs show great prospects in modifying the drug release characteristics and could be applied to any conventional immediate-release product.

Surface Engineering Methods for Powder Bed Printed Tablets to Optimize External Smoothness and Facilitate the Application of Different Coatings

In a previous attempt to achieve ileo-colonic targeting of bovine intestinal alkaline phosphatase (BIAP), we applied a pH-dependent coating, the ColoPulse coating, directly on powder bed printed (PBP) tablets. However, the high surface roughness necessitated an additional sub-coating layer [Nguyen, K. T. T., Pharmaceutics 2022]. In this study, we aimed to find a production method for PBP tablets containing BIAP that allows the direct application of coating systems. Alterations of the printing parameters, binder content, and printing layer height, when combined, were demonstrated to create visually less rough PBP tablets. The addition of ethanol vapor treatment further improved the surface's smoothness significantly. These changes enabled the direct application of the ColoPulse, or enteric coating, without a sub-coating. In vitro release testing showed the desired ileo-colonic release or upper-intestinal release for ColoPulse or enteric-coated tablets, respectively. Tablets containing BIAP, encapsulated within an inulin glass, maintained a high enzymatic activity (over 95%) even after 2 months of storage at 2-8 °C. Importantly, the coating process did not affect the activity of BIAP. In this study, we demonstrate, for the first time, the successful production of PBP tablets with surfaces that are directly coatable with the ColoPulse coating while preserving the stability of the encapsulated biopharmaceutical, BIAP.

Accelerated reconstruction of rat calvaria bone defect using 3D-printed scaffolds coated with hydroxyapatite/bioglass

Self-healing and autologous bone graft of calvaraial defects can be challenging. Therefore, the fabrication of scaffolds for its rapid and effective repair is a promising field of research. This paper provided a comparative study on the ability of Three-dimensional (3D) printed polycaprolactone (PCL) scaffolds and PCL-modified with the hydroxyapatite (HA) and bioglasses (BG) bioceramics scaffolds in newly bone formed in calvaria defect area. The studied 3D-printed PCL scaffolds were fabricated by fused deposition layer-by-layer modeling. After the evaluation of cell adhesion on the surface of the scaffolds, they were implanted into a rat calvarial defect model. The rats were divided into four groups with scaffold graft including PCL, PCL/HA, PCL/BG, and PCL/HA/BG and a non-explant control group. The capacity of the 3D-printed scaffolds in calvarial bone regeneration was investigated using micro computed tomography scan, histological and immunohistochemistry analyses. Lastly, the expression levels of several bone related genes as well as the expression of miR-20a and miR-17-5p as positive regulators and miR-125a as a negative regulator in osteogenesis pathways were also investigated. The results of this comparative study have showed that PCL scaffolds with HA and BG bioceramics have a great range of potential applications in the field of calvaria defect treatment.

Development of Diclofenac Sodium 3D Printed Cylindrical and Tubular-Shaped Tablets through Hot Melt Extrusion and Fused Deposition Modelling Techniques

The present study aimed to develop 3D printed dosage forms, using custom-made filaments loaded with diclofenac sodium (DS). The printed tablets were developed by implementing a quality by design (QbD) approach. Filaments with adequate FDM 3D printing characteristics were produced via hot melt extrusion (HME). Their formulation included DS as active substance, polyvinyl alcohol (PVA) as a polymer, different types of plasticisers (mannitol, erythritol, isomalt, maltodextrin and PEG) and superdisintegrants (crospovidone and croscarmellose sodium). The physicochemical and mechanical properties of the extruded filaments were investigated through differential scanning calorimetry (DSC), X-ray diffraction (XRD) and tensile measurements. In addition, cylindrical-shaped and tubular-shaped 3D dosage forms were printed, and their dissolution behaviour was assessed via various drug release kinetic models. DSC and XRD results demonstrated the amorphous dispersion of DS into the polymeric filaments. Moreover, the 3D printed tablets, regardless of their composition, exhibited a DS release of nearly 90% after 45 min at pH 6.8, while their release behaviour was effectively described by the Korsmeyer-Peppas model. Notably, the novel tube design, which was anticipated to increase the drug release rate, proved the opposite based on the in vitro dissolution study results. Additionally, the use of crospovidone increased DS release rate, whereas croscarmellose sodium decreased it.

Engineering 3D-Printed Advanced Healthcare Materials for Periprosthetic Joint Infections

The use of additive manufacturing or 3D printing in biomedicine has experienced fast growth in the last few years, becoming a promising tool in pharmaceutical development and manufacturing, especially in parenteral formulations and implantable drug delivery systems (IDDSs). Periprosthetic joint infections (PJIs) are a common complication in arthroplasties, with a prevalence of over 4%. There is still no treatment that fully covers the need for preventing and treating biofilm formation. However, 3D printing plays a major role in the development of novel therapies for PJIs. This review will provide a deep understanding of the different approaches based on 3D-printing techniques for the current management and prophylaxis of PJIs. The two main strategies are focused on IDDSs that are loaded or coated with antimicrobials, commonly in combination with bone regeneration agents and 3D-printed orthopedic implants with modified surfaces and antimicrobial properties. The wide variety of printing methods and materials have allowed for the manufacture of IDDSs that are perfectly adjusted to patients' physiognomy, with different drug release profiles, geometries, and inner and outer architectures, and are fully individualized, targeting specific pathogens. Although these novel treatments are demonstrating promising results, in vivo studies and clinical trials are required for their translation from the bench to the market.

Recent patent-based review on the role of three-dimensional printing technology in pharmaceutical and biomedical applications

Three-dimensional printing (3DP) is emerging as an innovative manufacturing technology for biomedical and pharmaceutical applications, since the US FDA approval of Spritam as a 3D-printed drug. In the present review, we have highlighted the potential benefits of 3DP technology in healthcare, such as the ability to create patient-specific medical devices and implants, as well as the possibility of on-demand production of drugs and personalized dosage forms. We have further discussed future research to optimize 3DP processes and materials for pharmaceutical and biomedical applications. Cohesively, we have put forward the current state of active patents and applications related to 3DP technology in the healthcare and pharmaceutical industries including hearing aids, prostheses, medical devices and drug-delivery systems.

Development of 3D printed mini-waffle shapes containing hydrocortisone for children's personalized medicine

Hydrocortisone is mainly used in the substitution treatment of adrenal insufficiency which results in a dysregulation of cortisol. Compounding of hydrocortisone capsules remains the only low-dose oral treatment suitable for the pediatric population. However, capsules often show non-compliance in mass and content uniformity. Three-dimensional printing offers the prospect of practising personalized medicine for vulnerable patients like children. The goal of this work is to develop low-dose solid oral forms containing hydrocortisone by hot-melt extrusion coupled with fused deposition modeling for the pediatric population. Formulation, design and processes temperatures were optimized to produce printed forms with the desired characteristics. Red mini-waffle shapes containing drug loads of 2, 5 and 8 mg were successfully printed. This new 3D design allow to release more than 80% of the drug in 45 minutes indicating a conventional release like the one obtained with capsules. Mass and content uniformity, hardness and friability tests complied with European Pharmacopeia specifications, despite the considerable challenge of the small dimensions of the forms. This study demonstrates that FDM can be used to produce innovative pediatric-friendly printed shapes of an advanced pharmaceutical quality to practice personalize medicine.

Three Dimensional Printing and Its Applications Focusing on Microneedles for Drug Delivery

Microneedles (MNs) are considered to be a novel smart injection system that causes significantly low skin invasion upon puncturing, due to the micron-sized dimensions that pierce into the skin painlessly. This allows transdermal delivery of numerous therapeutic molecules, such as insulin and vaccines. The fabrication of MNs is carried out through conventional old methods such as molding, as well as through newer and more sophisticated technologies, such as three-dimensional (3D) printing, which is considered to be a superior, more accurate, and more time- and production-efficient method than conventional methods. Three-dimensional printing is becoming an innovative method that is used in education through building intricate models, as well as being employed in the synthesis of fabrics, medical devices, medical implants, and orthoses/prostheses. Moreover, it has revolutionary applications in the pharmaceutical, cosmeceutical, and medical fields. Having the capacity to design patient-tailored devices according to their dimensions, along with specified dosage forms, has allowed 3D printing to stand out in the medical field. The different techniques of 3D printing allow for the production of many types of needles with different materials, such as hollow MNs and solid MNs. This review covers the benefits and drawbacks of 3D printing, methods used in 3D printing, types of 3D-printed MNs, characterization of 3D-printed MNs, general applications of 3D printing, and transdermal delivery using 3D-printed MNs.

A Review on Physicochemical Properties of Polymers Used as Filaments in 3D-Printed Tablets

Three-dimensional (3D) printing technology has presently been explored widely in the field of pharmaceutical research to produce various conventional as well as novel dosage forms such as tablets, capsules, oral films, pellets, subcutaneous implants, scaffolds, and vaginal rings. The use of this innovative method is a good choice for its advanced technologies and the ability to make tailored medicine specifically for individual patient. There are many 3D printing systems that are used to print tablets, implants, and vaginal rings. Among the available systems, the fused deposition modeling (FDM) is widely utilized. The FDM has been regarded as the best choice of printer as it shows high potential in the production of tablets as a unit dose in 3D printing medicine manufacturing. In order to design a 3D-printed tablet or other dosage forms, the physicochemical properties of polymers play a vital role. One should have proper knowledge about the polymer's properties so that one can select appropriate polymers in order to design 3D-printed dosage form. This review highlighted the various physicochemical properties of polymers that are currently used as filaments in 3D printing. In this manuscript, the authors also discussed various systems that are currently adopted in the 3D printing.

3D-printing-assisted synthesis of paclitaxel-loaded niosomes functionalized by cross-linked gelatin/alginate composite: Large-scale synthesis and in-vitro anti-cancer evaluation

Breast cancer is one of the most lethal cancers, especially in women. Despite many efforts, side effects of anti-cancer drugs and metastasis are still the main challenges in breast cancer treatment. Recently, advanced technologies such as 3D-printing and nanotechnology have created new horizons in cancer treatment. In this work, we report an advanced drug delivery system based on 3D-printed gelatin-alginate scaffolds containing paclitaxel-loaded niosomes (Nio-PTX@GT-AL). The morphology, drug release, degradation, cellular uptake, flow cytometry, cell cytotoxicity, migration, gene expression, and caspase activity of scaffolds, and control samples (Nio-PTX, and Free-PTX) were investigated. Results demonstrated that synthesized niosomes had spherical-like, in the range of 60-80 nm with desirable cellular uptake. Nio-PTX@GT-AL and Nio-PTX had a sustained drug release and were biodegradable. Cytotoxicity studies revealed that the designed Nio-PTX@GT-AL scaffold had <5 % cytotoxicity against non-tumorigenic breast cell line (MCF-10A) but showed 80 % cytotoxicity against breast cancer cells (MCF-7), which was considerably more than the anti-cancer effects of control samples. In migration evaluation (scratch-assay), approximately 70 % reduction of covered surface area was observed. The anticancer effect of the designed nanocarrier could be attributed to gene expression regulation, where a significant increase in the expression and activity of genes promoting apoptosis (CASP-3, CASP-8, and CASP-9) and inhibiting metastasis (Bax, and p53) and a remarkable decrease in metastasis-enhancing genes (Bcl2, MMP-2, and MMP-9) were observed. Also, flow cytometry results declared that Nio-PTX@GT-AL reduced necrosis and increased apoptosis considerably. The results of this study prove that employing 3D-printing and niosomal formulation is an effective approach in designing nanocarriers for efficient drug delivery applications.

Skin-interfaced electronics: A promising and intelligent paradigm for personalized healthcare

Skin-interfaced electronics (skintronics) have received considerable attention due to their thinness, skin-like mechanical softness, excellent conformability, and multifunctional integration. Current advancements in skintronics have enabled health monitoring and digital medicine. Particularly, skintronics offer a personalized platform for early-stage disease diagnosis and treatment. In this comprehensive review, we discuss (1) the state-of-the-art skintronic devices, (2) material selections and platform considerations of future skintronics toward intelligent healthcare, (3) device fabrication and system integrations of skintronics, (4) an overview of the skintronic platform for personalized healthcare applications, including biosensing as well as wound healing, sleep monitoring, the assessment of SARS-CoV-2, and the augmented reality-/virtual reality-enhanced human-machine interfaces, and (5) current challenges and future opportunities of skintronics and their potentials in clinical translation and commercialization. The field of skintronics will not only minimize physical and physiological mismatches with the skin but also shift the paradigm in intelligent and personalized healthcare and offer unprecedented promise to revolutionize conventional medical practices.

Technological Aspects and Evaluation Methods for Polymer Matrices as Dental Drug Carriers

The development of polymer matrices as dental drug carriers takes into account the following technological aspects of the developed formulations: the composition and the technology used to manufacture them, which affect the properties of the carriers, as well as the testing methods for assessing their behavior at application sites. The first part of this paper characterizes the methods for fabricating dental drug carriers, i.e., the solvent-casting method (SCM), lyophilization method (LM), electrospinning (ES) and 3D printing (3DP), describing the selection of technological parameters and pointing out both the advantages of using the mentioned methods and their limitations. The second part of this paper describes testing methods to study the formulation properties, including their physical and chemical, pharmaceutical, biological and in vivo evaluation. Comprehensive in vitro evaluation of carrier properties permits optimization of formulation parameters to achieve prolonged retention time in the dynamic oral environment and is essential for explaining carrier behavior during clinical evaluation, consequently enabling the selection of the optimal formulation for oral application.

Influence of formulation variables on the processability and properties of tablets manufactured by fused deposition modelling

The present work studied the influence of different formulation variables (defined also as factors), namely, different polymers (HPC EF, PVA and HPMC-AS LG), drugs with different water solubilities (paracetamol, hydrochlorothiazide and celecoxib) and drug loads (10 or 30 %) on their processability by HME and FDM. Both filaments and tablets were characterized for physic and chemical properties (DSC, XRPD, FTIR) and performance properties (drug content, in vitro drug release). Experiments were designed to highlight relationships between the 3 factors selected and the mechanical properties of filaments, tablet mass and dissolution profiles of the model drugs from printed tablets. While the combination of hydrochlorothiazide and HPMC-AS LG could not be extruded, the combination of paracetamol with HPC EF turned the filaments too ductile and not stiff enough hampering the process of printing. All other polymer and drug combinations could be successfully extruded and printed. Models reflected the influence of the solubility of the drug considered but not the drug load in formulations. The ranking of the drug release rates was in good agreement with their solubilities. Furthermore, PVA presenting the fastest swelling rate, promoted the fastest drugs' releases in comparison with the other polymers studied. Overall, the study enabled the identification of the key factors affecting the properties of printed tablets, with the proposal of a model that has valued the relative contribution of each factor to the overall performance of tablets.

Exploring new frontiers in drug delivery with minimally invasive microneedles: fabrication techniques, biomedical applications and regulatory aspects

INTRODUCTION

Transdermal drug delivery is limited by the stratum corneum, inhibiting the therapeutic potential of the permeants. Microneedles (MN) have opened new frontiers in transdermal drug delivery systems. These micro-sized needles offer painless and accentuated delivery of drugs even with high molecular weights.

AREAS COVERED

The review embodies drug delivery strategies with microneedles with a description of MN types and fabrication techniques using various materials. The application of MN is not limited to drug delivery, but it also encompasses in vaccine delivery, diagnosis, phlebotomy and even in the cosmetic industry. The review also tabulates microneedle-based marketed formulations. In a nutshell, we aim to present a panoramic view of microneedles including the design, applications, and regulatory aspects of MN.

EXPERT OPINION

With the availability of numerous materials at the disposal of pharmaceutical scientists; the microneedle-based drug delivery technology has offered significant interventions towards the management of chronic maladies including cardiovascular disorders, diabetes, asthma, mental depression, etc. As happens with any new technology there are concerns with MN also such as biocompatibility issues with the material used for the fabrication. Nevertheless, the pharmaceutical industry must strive for preparing harmless, efficient, and cost-effective MN based delivery systems for wider acceptance and patient compliance.

3D Printed Pharmaceutical Systems for Personalized Treatment in Metabolic Syndrome

The current healthcare system is widely based on the concept of “one size fit for all”, which emphasizes treating a disease by prescribing the same drug to all patients with equivalent doses and dosing frequency. This medical treatment scenario has shown varied responses with either no or weak pharmacological effects and exaggerated adverse reactions preceded by more patient complications. The hitches to the concept of “one size fits all” have devoted the attention of many researchers to unlocking the concept of personalized medicine (PM). PM delivers customized therapy with the highest safety margin for an individual patient’s needs. PM has the potential to revolutionize the current healthcare system and pave the way to alter drug choices and doses according to a patient’s clinical responses, providing physicians with the best treatment outcomes. The 3D printing techniques is a solid-form fabrication method whereby successive layers of materials based on computer-aided designs were deposited to form 3D structures. The 3D printed formulation achieves PM goals by delivering the desired dose according to patient needs and drug release profile to achieve a patient’s personal therapeutic and nutritional needs. This pre-designed drug release profile attains optimum absorption and distribution, exhibiting maximum efficacy and safety profiles. This review aims to focus on the role of the 3D printing technique as a promising tool to design PM in metabolic syndrome (MS).

Recent Advances in the Applications of Additive Manufacturing (3D Printing) in Drug Delivery: A Comprehensive Review

There has been a tremendous increase in the investigations of three-dimensional (3D) printing for biomedical and pharmaceutical applications, and drug delivery in particular, ever since the US FDA approved the first 3D printed medicine, SPRITAM® (levetiracetam) in 2015. Three-dimensional printing, also known as additive manufacturing, involves various manufacturing techniques like fused-deposition modeling, 3D inkjet, stereolithography, direct powder extrusion, and selective laser sintering, among other 3D printing techniques, which are based on the digitally controlled layer-by-layer deposition of materials to form various geometries of printlets. In contrast to conventional manufacturing methods, 3D printing technologies provide the unique and important opportunity for the fabrication of personalized dosage forms, which is an important aspect in addressing diverse patient medical needs. There is however the need to speed up the use of 3D printing in the biopharmaceutical industry and clinical settings, and this can be made possible through the integration of modern technologies like artificial intelligence, machine learning, and Internet of Things, into additive manufacturing. This will lead to less human involvement and expertise, independent, streamlined, and intelligent production of personalized medicines. Four-dimensional (4D) printing is another important additive manufacturing technique similar to 3D printing, but adds a 4th dimension defined as time, to the printing. This paper aims to give a detailed review of the applications and principles of operation of various 3D printing technologies in drug delivery, and the materials used in 3D printing, and highlight the challenges and opportunities of additive manufacturing, while introducing the concept of 4D printing and its pharmaceutical applications.

Development and Characterization of Different Dosage Forms of Nifedipine/Indomethacin Fixed-Dose Combinations

Studies have shown that 40 individuals out of 100,000 are diagnosed with rheumatoid arthritis (RA) yearly, with a total of 1.3 million in the United States. Furthermore, the impact of RA in some cases can extend to cardiovascular diseases (CVD), as the studies showed that 84% of RA patients are at risk of developing hypertension. This study aims to design and develop different dosage forms (capsule-in-capsule and three-dimensional (3D) printed tablet) of nifedipine/indomethacin fixed-dose combination (FDC). The hot-melt extrusion (HME) was utilized alone and with fused deposition modeling (FDM) techniques The developed dosage forms were intended to provide delayed-extended and immediate release profiles for indomethacin and nifedipine, respectively. FDC dosage forms were successfully developed and characterized. Nifedipine formulations showed significant improvement in release profiles, having 94% of the drug release at 30 minutes compared with pure nifedipine, which had a percent release of 2%. Furthermore, the release of indomethacin was successfully delayed at a pH of 1.2 and extended at a pH of 6.8. Differential scanning calorimetry results showed endothermic crystalline peaks at 165 °C and 176 °C for indomethacin and nifedipine, respectively. Moreover, the thermal analysis of all formulations showed the absence of the endothermic peaks indicating complete solubilization of indomethacin and nifedipine in the polymeric carriers. All formulations had post-processing drug content in the range of 95% to 98%. Moreover, results from the stability study showed that all formulations were able to remain chemically and physically stable with no signs of recrystallization or degradation. The designed FDC dosage forms could improve the quality of life by enhancing patient compliance and preventing the need for polypharmacy.

3D-Printed Radiopaque Microdevices with Enhanced Mucoadhesive Geometry for Oral Drug Delivery

During the past decades, microdevices have been evaluated as a means to overcome challenges within oral drug delivery, thus improving bioavailability. Fabrication of microdevices is often limited to planar or simple 3D designs. Therefore, this work explores how microscale stereolithography 3D printing can be used to fabricate radiopaque microcontainers with enhanced mucoadhesive geometries, which can enhance bioavailability by increasing gastrointestinal retention. Ex vivo force measurements suggest increased mucoadhesion of microcontainers with adhering features, such as pillars and arrows, compared to a neutral design. In vivo studies, utilizing planar X-ray imaging, show the time-dependent gastrointestinal location of microcontainers, whereas computed tomography scanning and cryogenic scanning electron microscopy reveal information about their spatial dynamics and mucosal interactions, respectively. For the first time, the effect of 3D microdevice modifications on gastrointestinal retention is traced in vivo, and the applied methods provide a much-needed approach for investigating the impact of device design on gastrointestinal retention.

Pilot-scale binder jet 3D printing of sustained release solid dosage forms

The additive nature and versatility of 3D printing show great promise in the rapid prototyping of solid dosage forms for clinical trials and mass customization for personalized medicine applications. This paper reports the formulation and process development of sustained release solid dosage forms, termed "printlets", using a pilot-scale binder jetting (BJT) 3D printer and acetaminophen (APAP) as the model drug. With the inclusion of hydroxypropyl methylcellulose (HPMC) as a release retardant polymer in the print powder, the drug release time of APAP increased considerably from minutes to hours. However, given the swelling propensity of HPMC, a thicker layer of powder must be laid down during printing to avoid any shape distortion of the printlets. For a fixed print volume, the level of binder saturation (i.e., ratio between the liquid binder and powder in the as-printed sample) is inversely proportional to the thickness of the spread powder layer. An increase in the spread powder layer inadvertently resulted in a lower level of binder saturation and consequently weaker printlets. By increasing the level of binder saturation with jetting from more print heads, the mechanical strength of printlets containing 18% HPMC was successfully restored. The resultant printlets have a drug release time of 3.5 h and a breaking force of 12.5 kgf that is comparable to the fast-disintegrating printlets containing no HPMC and surpasses manually pressed tablets with the same HPMC content.

Porous Microneedles for Therapy and Diagnosis: Fabrication and Challenges

The use of microneedles (MNs), an innovative transdermal technology, enables efficient, convenient, painless, and controlled-release drug delivery. Porous microneedles (pMNs), special MNs with abundant interconnected pores that can produce capillary action, are gaining increasing attention as a novel MNs technology. pMNs can actively adsorb bioactive ingredients from solutions of drugs or vaccines for in vivo delivery or from interstitial skin fluids (ISFs) for wearable and point-of-care testing (POCT) products. Different pore sizes and porosities of pMNs can be achieved with different materials and preparation processes, which makes the application of pMNs adaptable to multiple scenarios. In addition, easier and faster detection will be accomplished by the smart combination of pMNs with other detection technologies. This paper aims to summarize the recent research progress of pMNs, focusing on the influence of various materials and their corresponding preparation methods on its structure and function display, discussing the key issues and looking forward to the future development.

Additive manufacturing technologies with emphasis on stereolithography 3D printing in pharmaceutical and medical applications: A review

Three-dimensional (3D) printing or Additive Manufacturing (AM) technology is an innovative tool with great potential and diverse applications in various fields. As 3D printing has been burgeoning in recent times, a tremendous transformation can be envisaged in medical care, especially the manufacturing procedures leading to personalized medicine. Stereolithography (SLA), a vat-photopolymerization technique, that uses a laser beam, is known for its ability to fabricate complex 3D structures ranging from micron-size needles to life-size organs, because of its high resolution, precision, accuracy, and speed. This review presents a glimpse of varied 3D printing techniques, mainly expounding SLA in terms of the materials used, the orientation of printing, and the working mechanisms. The previous works that focused on developing pharmaceutical dosage forms, drug-eluting devices, and tissue scaffolds are presented in this paper, followed by the challenges associated with SLA from an industrial and regulatory perspective. Due to its excellent advantages, this technology could transform the conventional "one dose fits all" concept to bring digitalized patient-centric medication into reality.

Natural Alternatives to Non-biodegradable Polymers in 3D Printing of Pharmaceuticals

BACKGROUND

Due to potential toxicity, non-biodegradable polymers used in 3D (3-dimensional) printing of drugs could be dangerous for patient safety and the environment.

OBJECTIVE

This review aims to investigate the toxicity of non-biodegradable polymers and investigate the use of natural materials as an alternative in 3D printing medicines. The study evaluates the dangers connected to 3D printing.

METHODS

A review of the literature on various 3D printing processes, such as inkjet printing, fused filament manufacturing, and extrusion-related 3DP systems, was done for this study. Also, the use of cellulose derivatives and natural materials in 3D printing and their potential as active excipients was proposed.

RESULTS

The review identified potential toxicity risks linked to non-biodegradable polymers used in drug 3D printing. As a potential fix for this issue, the use of natural materials with improved mechanical and thermal properties was explored. The use of cellulose derivatives as an alternative to non-biodegradable polymers in 3D printing pharmaceuticals was also investigated in the study.

CONCLUSION

This study emphasises the significance of evaluating the risks connected to drug 3D printing and recommends using natural materials as an alternative to non-biodegradable polymers. More study is required to create secure and reliable 3D printing processes for pharmaceuticals.

3D printed PLGA implants: APF DDM vs. FDM

3D Printing offers a considerable potential for personalized medicines. This is especially true for customized biodegradable implants, matching the specific needs of each patient. Poly(lactic-co-glycolic acid) (PLGA) is frequently used as matrix former in biodegradable implants. However, yet relatively little is known on the technologies, which can be used for the 3D printing of PLGA implants. The aim of this study was to compare: (i) Arburg Plastic Freeforming Droplet Deposition Modeling (APF DDM), and (ii) Fused Deposition Modeling (FDM) to print mesh-shaped, ibuprofen-loaded PLGA implants. During APF DDM, individual drug-polymer droplets are deposited, fusing together to form filaments, which build up the implants. During FDM, continuous drug-polymer filaments are deposited to form the meshes. The implants were thoroughly characterized before and after exposure to phosphate buffer pH 7.4 using optical and scanning electron microscopy, GPC, DSC, drug release measurements and monitoring dynamic changes in the systems' dry & wet mass and pH of the bulk fluid. Interestingly, the mesh structures were significantly different, although the device design (composition & theoretical geometry) were the same. This could be explained by the fact that the deposition of individual droplets during APF DDM led to curved and rather thick filaments, resulting in a much lower mesh porosity. In contrast, FDM printing generated straight and thinner filaments: The open spaces between them were much larger and allowed convective mass transport during drug release. Consequently, most of the drug was already released after 4 d, when substantial PLGA set on. In the case of APF DDM printed implants, most of the drug was still entrapped at that time point and substantial polymer swelling transformed the meshes into more or less continuous PLGA gels. Hence, the diffusion pathways became much longer and ibuprofen release was controlled over 2 weeks.

Drop-on-powder 3D printing of amorphous high dose oral dosage forms: Process development, opportunities and printing limitations

Drop-on-powder 3D printing is able to produce highly drug loaded solid oral dosage forms. However, this technique is mainly limited to well soluble drugs. The majority of pipeline compounds is poorly soluble, though, and requires solubility enhancement, e.g., via formation of amorphous solid dispersions. This study presents a detailed and systematic development approach for the production of tablets containing high amounts of a poorly soluble, amorphized drug via drop-on-powder 3D printing (also known as binder jetting). Amorphization of the compound was achieved via hot-melt extrusion using the exemplary system of the model compound ketoconazole and copovidone as matrix polymer at drug loadings of 20% and 40%. The milled extrudate was used as powder for printing and the influence of inks and different ink-to-powder ratios on recrystallization of ketoconazole was investigated in a material-saving small-scale screening. Crystallinity assessment was performed using differential scanning calorimetry and polarized light microscopy to identify even small traces of crystallinity. Printing of tablets showed that the performed small-scale screening was capable to identify printing parameters for the development of amorphous and mechanically stable tablets via drop-on-powder printing. A stability study demonstrated physically stable tablets over twelve weeks at accelerated storage conditions.

3D printing of pharmaceuticals: approach from bench scale to commercial development

Background

The three-dimensional (3D) printing is paradigm shift in the healthcare sector. 3D printing is platform technologies in which complex products are developed with less number of additives. The easy development process gives edge over the conventional methods. Every individual needs specific dose treatment. ‘One size fits all’ is the current traditional approach that can shift to more individual specific in 3D printing. The present review aims to cover different perspectives regarding selection of drug, polymer and technological aspects for 3D printing. With respect to clinical practice, regulatory issue and industrial potential are also discussed in this paper.

Main body

The individualization of medicines with patient centric dosage form will become reality in upcoming future. It provides individual’s need of dose by considering genetic profile, physiology and diseased condition. The tailormade dosages with unique drug loading and release profile of different geometrical shapes and sizes can easily deliver therapeutic dose. The technology can fulfill growing demand of efficiency in the dose accuracy for the patient oriented sectors like pediatric, geriatric and also easy to comply with cGMP requirements of regulated market. The clinical practice can focus on prescribing each individual’s necessity of dose.

Conclusion

In the year 2015, FDA approved first 3D printed drug product, which is initiator in the new phase of manufacturing of pharmaceuticals. The tailormade formulations can be made in future for personalized medications. Regulatory approval from agencies can bring the 3DP product into the market. In the future, formulators can bring different sector-specific products for personalized need through 3DP pharmaceutical product.

Graphical Abstract

Learning to discover medicines

Discovering new medicines is the hallmark of the human endeavor to live a better and longer life. Yet the pace of discovery has slowed down as we need to venture into more wildly unexplored biomedical space to find one that matches today's high standard. Modern AI-enabled by powerful computing, large biomedical databases, and breakthroughs in deep learning offers a new hope to break this loop as AI is rapidly maturing, ready to make a huge impact in the area. In this paper, we review recent advances in AI methodologies that aim to crack this challenge. We organize the vast and rapidly growing literature on AI for drug discovery into three relatively stable sub-areas: (a) representation learning over molecular sequences and geometric graphs; (b) data-driven reasoning where we predict molecular properties and their binding, optimize existing compounds, generate de novo molecules, and plan the synthesis of target molecules; and (c) knowledge-based reasoning where we discuss the construction and reasoning over biomedical knowledge graphs. We will also identify open challenges and chart possible research directions for the years to come.

A Novel 3D Printing Particulate Manufacturing Technology for Encapsulation of Protein Therapeutics: Sprayed Multi Adsorbed-Droplet Reposing Technology (SMART)

Recently, various innovative technologies have been developed for the enhanced delivery of biologics as attractive formulation targets including polymeric micro and nanoparticles. Combined with personalized medicine, this area can offer a great opportunity for the improvement of therapeutics efficiency and the treatment outcome. Herein, a novel manufacturing method has been introduced to produce protein-loaded chitosan particles with controlled size. This method is based on an additive manufacturing technology that allows for the designing and production of personalized particulate based therapeutic formulations with a precise control over the shape, size, and potentially the geometry. Sprayed multi adsorbed-droplet reposing technology (SMART) consists of the high-pressure extrusion of an ink with a well determined composition using a pneumatic 3D bioprinting approach and flash freezing the extrudate at the printing bed, optionally followed by freeze drying. In the present study, we attempted to manufacture trypsin-loaded chitosan particles using SMART. The ink and products were thoroughly characterized by dynamic light scattering, rheometer, Scanning Electron Microscopy (SEM), and Fourier Transform Infra-Red (FTIR) and Circular Dichroism (CD) spectroscopy. These characterizations confirmed the shape morphology as well as the protein integrity over the process. Further, the effect of various factors on the production were investigated. Our results showed that the concentration of the carrier, chitosan, and the lyoprotectant concentration as well as the extrusion pressure have a significant effect on the particle size. According to CD spectra, SMART ensured Trypsin's secondary structure remained intact regardless of the ink composition and pressure. However, our study revealed that the presence of 5% (w/v) lyoprotectant is essential to maintain the trypsin's proteolytic activity. This study demonstrates, for the first time, the viability of SMART as a single-step efficient process to produce biologics-based stable formulations with a precise control over the particulate morphology which can further be expanded across numerous therapeutic modalities including vaccines and cell/gene therapies.

Formulation of a 3D Printed Biopharmaceutical: The Development of an Alkaline Phosphatase Containing Tablet with Ileo-Colonic Release Profile to Treat Ulcerative Colitis

Powder bed printing is a 3D-printing process that creates freeform geometries from powders, with increasing traction for personalized medicine potential. Little is known about its applications for biopharmaceuticals. In this study, the production of tablets containing alkaline phosphatase using powder bed printing for the potential treatment of ulcerative colitis (UC) was investigated, as was the coating of these tablets to obtain ileo-colonic targeting. The printing process was studied, revealing line spacing as a critical factor affecting tablet physical properties when using hydroxypropyl cellulose as the binder. Increasing line spacing yielded tablets with higher porosity. The enzymatic activity of alkaline phosphatase (formulated in inulin glass) remained over 95% after 2 weeks of storage at 45 °C. The subsequent application of a colonic targeting coating required a PEG 1500 sub-coating. In vitro release experiments, using a gastrointestinal simulated system, indicated that the desired ileo-colonic release was achieved. Less than 8% of the methylene blue, a release marker, was released in the terminal ileum phase, followed by a fast release in the colon phase. No significant impact from the coating process on the enzymatic activity was found. These tablets are the first to achieve both biopharmaceutical incorporation in powder bed printed tablets and ileo-colonic targeting, thus might be suitable for on-demand patient-centric treatment of UC.

3D printed oral solid dosage form: Modified release and improved solubility

Oral solid dosage form is currently the most common used form of drug. 3D Printing, also known as additive manufacturing (AM), can quickly print customized and individualized oral solid dosage form on demand. Compared with the traditional tablet manufacturing process, 3D Printing has many advantages. By rationally selecting the formulation composition and cleverly designing the printing structure, 3D printing can improve the solubility of the drug and achieve precise modify of the drug release. 3D printed oral solid dosage form, however, still has problems such as limitations in formulation selection. And the selection process of the formulation lacks scientificity and standardization. Structural design of some 3D printing approaches is relatively scarce. This article reviews the formulation selection and structure design of 3D printed oral solid dosage form, providing more ideas for achieving modified drug release and solubility improvement of 3D printed oral solid dosage form through more scientific and extensive formulation selection and more sophisticated structural design.