Stereolithography (SLA) 3D printing of ascorbic acid loaded hydrogels: A controlled release study

Improvements in the Production of Isosorbide Monomethacrylate Using a Biobased Catalyst and Liquid-Liquid Extraction Isolation for Modifications of Oil-Based Resins

The improved production of a polar curable monomer, isosorbide monomethacrylate (MISD), with methacrylic anhydride (MAAH) as an acyl donor, was performed. A sustainable and cheap catalyst, potassium acetate (CH3COOK), was used for a solvent-free synthesis, requiring only the equimolar amount of reagents (no excess). The production included the quantitative separation of the secondary product, methacrylic acid (MAA), preventing the reaction batch from the purification process (neutralization of MAA), and gaining a usable reagent. The synthesis resulted in a sufficient yield of MISD (61.8%) obtained by the liquid-liquid extraction process (LLE), which is a significant improvement in the process, avoiding the flash chromatography step in the isolation of MISD. The purity of synthesized and isolated MISD via the LLE was confirmed by 1H NMR, MS, and FTIR analyses. The thermal analyses, namely, DSC and TGA, were used to characterize the curability and thermal stability of MISD. The activation energy of MISD's curing was calculated (E a = 94.6 kJ/mol) along with the heat-resistant index (T s = 136.8). The polar character of isosorbide monomethacrylate was investigated in a mixture with epoxidized acrylated soybean oil (EASO). It was found that MISD is entirely soluble in EASO and can modify the rheological behavior and surface energy of EASO-based resins. The apparent viscosity of EASO at 30 °C (ηapp = 3413 mPa·s) decreased with the 50% content of MISD significantly (ηapp = 500 mPa·s), and the free surface energy value of EASO (γS = 42.2 mJ/m2) also increased with the 50% content of MISD (γS = 48.7 mJ/m2). The produced MISD can be successfully used as a diluent and the polarity modifier of curable oil-based resins.

Innovative technologies for the fabrication of 3D/4D smart hydrogels and its biomedical applications - A comprehensive review

Repairing and regenerating damaged tissues or organs, and restoring their functioning has been the ultimate aim of medical innovations. 'Reviving healthcare' blends tissue engineering with alternative techniques such as hydrogels, which have emerged as vital tools in modern medicine. Additive manufacturing (AM) is a practical manufacturing revolution that uses building strategies like molding as a viable solution for precise hydrogel manufacturing. Recent advances in this technology have led to the successful manufacturing of hydrogels with enhanced reproducibility, accuracy, precision, and ease of fabrication. Hydrogels continue to metamorphose as the vital compatible bio-ink matrix for AM. AM hydrogels have paved the way for complex 3D/4D hydrogels that can be loaded with drugs or cells. Bio-mimicking 3D cell cultures designed via hydrogel-based AM is a groundbreaking in-vivo assessment tool in biomedical trials. This brief review focuses on preparations and applications of additively manufactured hydrogels in the biomedical spectrum, such as targeted drug delivery, 3D-cell culture, numerous regenerative strategies, biosensing, bioprinting, and cancer therapies. Prevalent AM techniques like extrusion, inkjet, digital light processing, and stereo-lithography have been explored with their setup and methodology to yield functional hydrogels. The perspectives, limitations, and the possible prospects of AM hydrogels have been critically examined in this study.

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.

Soft and flexible polyvinyl alcohol/pullulan aerogels with fast and high water absorption capacity for facial mask substrates

Facial mask substrates commonly used in skincare are often considered unhealthy and environmentally unfriendly due to their composition of premoistened nonwovens containing various preservatives. This study aims to address this issue by developing a preservative-free degradable aerogel made from polyvinyl alcohol (PVA)/pullulan (PUL) using a unidirectional freeze-drying method. The aerogels had ordered three-dimensional porous structures and exhibited desirable mechanical properties. They were soft and flexible in both dry and wet states, and their Young's moduli were comparable to that of human skin. The aerogels had high porosity, ranging from 93.0 % to 95.1 %, and exhibited a high water absorption rate and water absorption capacity (ranging from 7.5 g/g to 10.1 g/g). After 30 min of water evaporation, the aerogels showed excellent moisture retention, ranging from 88 % to 93 %. Additionally, the PVA/PUL aerogel efficiently loaded and released active ingredients, such as rapidly releasing ascorbic acid (> 90 % within 30 min). These findings suggest that the PVA/PUL aerogel has potential as a material for facial mask substrates.

Application of 3D printing in early phase development of pharmaceutical solid dosage forms

Three-dimensional printing (3DP) is an emerging technology, offering the possibility for the development of dose-customized, effective, and safe solid oral dosage forms (SODFs). Although 3DP has great potential, it does come with certain limitations, and the traditional drug manufacturing platforms remain the industry standard. The consensus appears to be that 3DP technology is expected to benefit personalized medicine the most, but that it is unlikely to replace conventional manufacturing for mass production. The 3DP method, on the other hand, could prove well-suited for producing small batches as an adaptive manufacturing technique for enabling adaptive clinical trial design for early clinical studies. The purpose of this review is to discuss recent advancements in 3DP technologies for SODFs and to focus on the applications for SODFs in the early clinical development stages, including a discussion of current regulatory challenges and quality controls.

Advanced Nanomaterials in Medical 3D Printing

3D printing is now recognized as a significant tool for medical research and clinical practice, leading to the emergence of medical 3D printing technology. It is essential to improve the properties of 3D-printed products to meet the demand for medical use. The core of generating qualified 3D printing products is to develop advanced materials and processes. Taking advantage of nanomaterials with tunable and distinct physical, chemical, and biological properties, integrating nanotechnology into 3D printing creates new opportunities for advancing medical 3D printing field. Recently, some attempts are made to improve medical 3D printing through nanotechnology, providing new insights into developing advanced medical 3D printing technology. With high-resolution 3D printing technology, nano-structures can be directly fabricated for medical applications. Incorporating nanomaterials into the 3D printing material system can improve the properties of the 3D-printed medical products. At the same time, nanomaterials can be used to expand novel medical 3D printing technologies. This review introduced the strategies and progresses of improving medical 3D printing through nanotechnology and discussed challenges in clinical translation.

Semisolid extrusion 3D printing of Dolutegravir-Chitosan nanoparticles laden polymeric buccal films: personalized solution for pediatric treatment

In this work, the semi solid extrusion 3D printing process was utilized to incorporate anti-HIV drug Dolutegravir and its nanoparticles into the buccal film (BF) that was fabricated using the developed polymer ink. The composite made of polyvinyl alcohol (PVA) and sodium alginate was processed into a 3D printing polymer ink with optimum viscosity (9587 ± 219 cP) needed for the seamless extrusion through the nozzle of the 3D printer. The formulated BFs were assessed for its physical properties like weight (0.414 ± 0.3 g), thickness (1.54 ± 0.02 mm), swelling index (18.5 ± 0.91%), and mucoadhesiveness strength (0.165 ± 0.09 N) etc, The structural integrity and the surface morphology of the developed BFs were investigated by scanning electron microscopy analysis. The chemical stability and the solid-state nature of the drug in the BFs were assessed by Fourier transform infrared and x-ray diffraction analysis respectively. Further the BFs were assessed for drug dissolutionin-vitroandex-vivo, to study the effect of polymer composition and printing condition on the dissolution profile of the drug in the simulated salivary fluid. The results demonstrated that the developed PVA based polymer ink for 3D printing utilizing pressure is a versatile approach in the context of manufacturing mucoadhesive BFs customized in terms of shape and the amount of drug loaded.

3D-printed dosage forms for oral administration: a review

Oral administration is the most commonly used form of treatment due to its advantages, including high patient compliance, convenient administration, and minimal preparation required. However, the traditional preparation process of oral solid preparation has many defects. Although continuous manufacturing line that combined all the unit operations has been developed and preliminarily applied in the pharmaceutical industry, most of the currently used manufacturing processes are still complicated and discontinuous. As a result, these complex production steps will lead to low production efficiency and high quality control risk of the final product. Additionally, the large-scale production mode is inappropriate for the personalized medicines, which commonly is customized with small amount. Several attractive techniques, such as hot-melt extrusion, fluidized bed pelletizing and spray drying, could effectively shorten the process flow, but still, they have inherent limitations that are challenging to address. As a novel manufacturing technique, 3D printing could greatly reduce or eliminate these disadvantages mentioned above, and could realize a desirable continuous production for small-scale personalized manufacturing. In recent years, due to the participation of 3D printing, the development of printed drugs has progressed by leaps and bounds, especially in the design of oral drug dosage forms. This review attempts to summarize the new development of 3D printing technology in oral preparation and also discusses their advantages and disadvantages as well as potential applications.

Three-Dimensional Printing as a Progressive Innovative Tool for Customized and Precise Drug Delivery

While using three-dimensional printing, materials are deposited layer by layer in accordance with the digital model created by computer-aided design software. Numerous research teams have shown interest in this technology throughout the last few decades to produce various dosage forms in the pharmaceutical industry. The number of publications has increased since the first printed medicine was approved in 2015 by Food and Drug Administration. Considering this, the idea of creating complex, custom-made structures that are loaded with pharmaceuticals for tissue engineering and dose optimization is particularly intriguing. New approaches and techniques for creating unique medication delivery systems are made possible by the development of additive manufacturing keeping in mind the comparative advantages it has over conventional methods of manufacturing medicaments. This review focuses on three-dimensional printed formulations grouped in orally disintegrated tablets, buccal films, implants, suppositories, and microneedles. The various types of techniques that are involved in it are summarized. Additionally, challenges and applications related to three-dimensional printing of pharmaceuticals are also being discussed.

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.

3D-Printed Hydrogel for Diverse Applications: A Review

Hydrogels have emerged as a versatile and promising class of materials in the field of 3D printing, offering unique properties suitable for various applications. This review delves into the intersection of hydrogels and 3D printing, exploring current research, technological advancements, and future directions. It starts with an overview of hydrogel basics, including composition and properties, and details various hydrogel materials used in 3D printing. The review explores diverse 3D printing methods for hydrogels, discussing their advantages and limitations. It emphasizes the integration of 3D-printed hydrogels in biomedical engineering, showcasing its role in tissue engineering, regenerative medicine, and drug delivery. Beyond healthcare, it also examines their applications in the food, cosmetics, and electronics industries. Challenges like resolution limitations and scalability are addressed. The review predicts future trends in material development, printing techniques, and novel applications.

Investigations of hybrid infill pattern in additive manufactured tablets: A novel approach towards tunable drug release

The significance of 3D printing has risen exponentially in biomedical and pharmaceutical applications. Its potential in the field of fabricating drug delivery systems, by virtue of processing biocompatible polymers, has been very lucrative. This work aims to tap the interstitial drug delivery kinetics that are often inaccessible through machine-specific infill patterns in additive manufactured tablets fabricated using PVA biopolymer as an excipient. In this regard, a myo-inositol containing tablet has been printed using Fused Deposition Modeling preceded by Hot Melt Extrusion drug loading route. Two machine-specific infill patterns were taken, namely straight and grid. Later, these two distinct patterns were juxtaposed to obtain novel hybrid infill patterns in the tablets. Then, these tablets and their filament were subjected to various thermal, mechanical, imaging and pharmaceutical characterization tests to assess the feasibility of the research attempt. Finally, dissolution tests were conducted to evaluate their dissolution behavior over a time period. The characterization tests proved the scientific viability of this attempt along with amorphous existence of drug in the polymeric filament. The dissolution results showed favorable drug release by achieving interstitial dissolution timings with surface area/volume (SA/V) ratio being found to be the principal factor.

Light-oriented 3D printing of liquid crystal/photocurable resins and in-situ enhancement of mechanical performance

Additive manufacturing technology has significantly impacted contemporary industries due to its ability to generate intricate computer-designed geometries. However, 3D-printed polymer parts often possess limited application potential, primarily because of their weak mechanical attributes. To overcome this drawback, this study formulates liquid crystal/photocurable resins suitable for the stereolithography technique by integrating 4'-pentyl-4-cyanobiphenyl with a photosensitive acrylic resin. This study demonstrates that stereolithography facilitates the precise modulation of the existing liquid crystal morphology within the resin. Furthermore, the orientation of the liquid crystal governs the oriented polymerization of monomers or prepolymers bearing acrylate groups. The products of this 3D printing approach manifest anisotropic behavior. Remarkably, when utilizing liquid crystal/photocurable resins, the resulting 3D-printed objects are approximately twice as robust as those created using commercial resins in terms of their tensile, flexural, and impact properties. This pioneering approach holds promise for realizing autonomously designed structures that remain elusive with present additive manufacturing techniques.

Enhancing antioxidant delivery through 3D printing: a pathway to advanced therapeutic strategies

The rapid advancement of 3D printing has transformed industries, including medicine and pharmaceuticals. Integrating antioxidants into 3D-printed structures offers promising therapeutic strategies for enhanced antioxidant delivery. This review explores the synergistic relationship between 3D printing and antioxidants, focusing on the design and fabrication of antioxidant-loaded constructs. Incorporating antioxidants into 3D-printed matrices enables controlled release and localized delivery, improving efficacy while minimizing side effects. Customization of physical and chemical properties allows tailoring of antioxidant release kinetics, distribution, and degradation profiles. Encapsulation techniques such as direct mixing, coating, and encapsulation are discussed. Material selection, printing parameters, and post-processing methods significantly influence antioxidant release kinetics and stability. Applications include wound healing, tissue regeneration, drug delivery, and personalized medicine. This comprehensive review aims to provide insights into 3D printing-assisted antioxidant delivery systems, facilitating advancements in medicine and improved patient outcomes for oxidative stress-related disorders.

Integration of 3D Printing-Coelectrospinning: Concept Shifting in Biomedical Applications

Porous structures with sizes between the submicrometer and nanometer scales can be produced using efficient and adaptable electrospinning technology. However, to approximate desirable structures, the construction lacks mechanical sophistication and conformance and requires three-dimensional solitary or multifunctional structures. The diversity of high-performance polymers and blends has enabled the creation of several porous structural conformations for applications in advanced materials science, particularly in biomedicine. Two promising technologies can be combined, such as electrospinning with 3D printing or additive manufacturing, thereby providing a straightforward yet flexible technique for digitally controlled shape-morphing fabrication. The hierarchical integration of configurations is used to imprint complex shapes and patterns onto mesostructured, stimulus-responsive electrospun fabrics. This technique controls the internal stresses caused by the swelling/contraction mismatch in the in-plane and interlayer regions, which, in turn, controls the morphological characteristics of the electrospun membranes. Major innovations in 3D printing, along with additive manufacturing, have led to the production of materials and scaffold systems for tactile and wearable sensors, filtration structures, sensors for structural health monitoring, tissue engineering, biomedical scaffolds, and optical patterning. This review discusses the synergy between 3D printing and electrospinning as a constituent of specific microfabrication methods for quick structural prototypes that are expected to advance into next-generation constructs. Furthermore, individual techniques, their process parameters, and how the fabricated novel structures are applied holistically in the biomedical field have never been discussed in the literature. In summary, this review offers novel insights into the use of electrospinning and 3D printing as well as their integration for cutting-edge applications in the biomedical field.

Spatial-Selective Volumetric 4D Printing and Single-Photon Grafting of Biomolecules within Centimeter-Scale Hydrogels via Tomographic Manufacturing

Conventional additive manufacturing and biofabrication techniques are unable to edit the chemicophysical properties of the printed object postprinting. Herein, a new approach is presented, leveraging light-based volumetric printing as a tool to spatially pattern any biomolecule of interest in custom-designed geometries even across large, centimeter-scale hydrogels. As biomaterial platform, a gelatin norbornene resin is developed with tunable mechanical properties suitable for tissue engineering applications. The resin can be volumetrically printed within seconds at high resolution (23.68 ± 10.75 μm). Thiol-ene click chemistry allows on-demand photografting of thiolated compounds postprinting, from small to large (bio)molecules (e.g., fluorescent dyes or growth factors). These molecules are covalently attached into printed structures using volumetric light projections, forming 3D geometries with high spatiotemporal control and ≈50 μm resolution. As a proof of concept, vascular endothelial growth factor is locally photografted into a bioprinted construct and demonstrated region-dependent enhanced adhesion and network formation of endothelial cells. This technology paves the way toward the precise spatiotemporal biofunctionalization and modification of the chemical composition of (bio)printed constructs to better guide cell behavior, build bioactive cue gradients. Moreover, it opens future possibilities for 4D printing to mimic the dynamic changes in morphogen presentation natively experienced in biological tissues.

Release Kinetics of Metronidazole from 3D Printed Silicone Scaffolds for Sustained Application to the Female Reproductive Tract

Sustained vaginal administration of antibiotics or probiotics has been proposed to improve treatment efficacy for bacterial vaginosis. 3D printing has shown promise for development of systems for local agent delivery. In contrast to oral ingestion, agent release kinetics can be fine-tuned by the 3D printing of specialized scaffold designs tailored for particular treatments while enhancing dosage effectiveness via localized sustained release. It has been challenging to establish scaffold properties as a function of fabrication parameters to obtain sustained release. In particular, the relationships between scaffold curing conditions, compressive strength, and drug release kinetics remain poorly understood. This study evaluates 3D printed scaffold formulation and feasibility to sustain the release of metronidazole, a commonly used antibiotic for BV. Cylindrical silicone scaffolds were printed and cured using three different conditions relevant to potential future incorporation of temperature-sensitive labile biologics. Compressive strength and drug release were monitored for 14d in simulated vaginal fluid to assess long-term effects of fabrication conditions on mechanical integrity and release kinetics. Scaffolds were mechanically evaluated to determine compressive and tensile strength, and elastic modulus. Release profiles were fitted to previous kinetic models to differentiate potential release mechanisms. The Higuchi, Korsmeyer-Peppas, and Peppas-Sahlin models best described the release, indicating similarity to release from insoluble or polymeric matrices. This study shows the feasibility of 3D printed silicone scaffolds to provide sustained metronidazole release over 14d, with compressive strength and drug release kinetics tuned by the fabrication parameters.

Energy Consumption and Carbon Footprint of 3D Printing in Pharmaceutical Manufacture

Achieving carbon neutrality is seen as an important goal in order to mitigate the effects of climate change, as carbon dioxide is a major greenhouse gas that contributes to global warming. Many countries, cities and organizations have set targets to become carbon neutral. The pharmaceutical sector is no exception, being a major contributor of carbon emissions (emitting approximately 55% more than the automotive sector for instance) and hence is in need of strategies to reduce its environmental impact. Three-dimensional (3D) printing is an advanced pharmaceutical fabrication technology that has the potential to replace traditional manufacturing tools. Being a new technology, the environmental impact of 3D printed medicines has not been investigated, which is a barrier to its uptake by the pharmaceutical industry. Here, the energy consumption (and carbon emission) of 3D printers is considered, focusing on technologies that have successfully been demonstrated to produce solid dosage forms. The energy consumption of 6 benchtop 3D printers was measured during standby mode and printing. On standby, energy consumption ranged from 0.03 to 0.17 kWh. The energy required for producing 10 printlets ranged from 0.06 to 3.08 kWh, with printers using high temperatures consuming more energy. Carbon emissions ranged between 11.60-112.16 g CO₂ (eq) per 10 printlets, comparable with traditional tableting. Further analyses revealed that decreasing printing temperature was found to reduce the energy demand considerably, suggesting that developing formulations that are printable at lower temperatures can reduce CO₂ emissions. The study delivers key initial insights into the environmental impact of a potentially transformative manufacturing technology and provides encouraging results in demonstrating that 3D printing can deliver quality medicines without being environmentally detrimental.

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).

Effect of Tartrazine as Photoabsorber for Improved Printing Resolution of 3D Printed "Ghost Tablets": Non-Erodible Inert Matrices

Stereolithography (SLA) 3D printing of pharmaceuticals suffers from the problem of light scattering, which leads to over-curing, resulting in the printing of objects that are non-compliant with design dimensions and the overloading of drugs. To minimize this problem, photoabsorbers such as tartrazine (food grade) can be used to absorb the stray light produced by scattering, leading to unintended photopolymerization. Ghost tablets (i.e., non-erodible inert matrices) were additively manufactured using SLA with varying ratios of polyethylene glycol diacrylate (PEGDA): polyethylene glycol (PEG) 300, along with tartrazine concentrations. The 3D printed ghost tablets containing maximum (0.03%) tartrazine were extremely precise in size and adhered to the nominal value of the metformin hydrochloride content. Resolution analysis reinstated the influence of tartrazine in achieving highly precise objects of even 0.07 mm² area. Furthermore, 3D printed ghost tablets were characterized using analytical means, and swelling studies. Additionally, ghost tablets were tested for their mechanical robustness using dynamic mechanical and texture analysis, and were able to withstand strains of up to 5.0% without structural failure. The printed ghost tablets displayed a fast metformin hydrochloride release profile, with 93.14% release after 12 h when the PEG 300 ratio was at its maximum. Ghost tablets were also subjected to in vivo X-ray imaging, and the tablets remained intact even after four hours of administration and were eventually excreted in an intact form through fecal excretion.

Microfluidic Organ-on-A-chip: A Guide to Biomaterial Choice and Fabrication

Organ-on-A-chip (OoAC) devices are miniaturized, functional, in vitro constructs that aim to recapitulate the in vivo physiology of an organ using different cell types and extracellular matrix, while maintaining the chemical and mechanical properties of the surrounding microenvironments. From an end-point perspective, the success of a microfluidic OoAC relies mainly on the type of biomaterial and the fabrication strategy employed. Certain biomaterials, such as PDMS (polydimethylsiloxane), are preferred over others due to their ease of fabrication and proven success in modelling complex organ systems. However, the inherent nature of human microtissues to respond differently to surrounding stimulations has led to the combination of biomaterials ranging from simple PDMS chips to 3D-printed polymers coated with natural and synthetic materials, including hydrogels. In addition, recent advances in 3D printing and bioprinting techniques have led to the powerful combination of utilizing these materials to develop microfluidic OoAC devices. In this narrative review, we evaluate the different materials used to fabricate microfluidic OoAC devices while outlining their pros and cons in different organ systems. A note on combining the advances made in additive manufacturing (AM) techniques for the microfabrication of these complex systems is also discussed.

3D Printing Technologies in Personalized Medicine, Nanomedicines, and Biopharmaceuticals

3D printing technologies enable medicine customization adapted to patients' needs. There are several 3D printing techniques available, but majority of dosage forms and medical devices are printed using nozzle-based extrusion, laser-writing systems, and powder binder jetting. 3D printing has been demonstrated for a broad range of applications in development and targeting solid, semi-solid, and locally applied or implanted medicines. 3D-printed solid dosage forms allow the combination of one or more drugs within the same solid dosage form to improve patient compliance, facilitate deglutition, tailor the release profile, or fabricate new medicines for which no dosage form is available. Sustained-release 3D-printed implants, stents, and medical devices have been used mainly for joint replacement therapies, medical prostheses, and cardiovascular applications. Locally applied medicines, such as wound dressing, microneedles, and medicated contact lenses, have also been manufactured using 3D printing techniques. The challenge is to select the 3D printing technique most suitable for each application and the type of pharmaceutical ink that should be developed that possesses the required physicochemical and biological performance. The integration of biopharmaceuticals and nanotechnology-based drugs along with 3D printing ("nanoprinting") brings printed personalized nanomedicines within the most innovative perspectives for the coming years. Continuous manufacturing through the use of 3D-printed microfluidic chips facilitates their translation into clinical practice.

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.

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.

Optimization of Initial Drug Distribution in Spherical Capsules for Personalized Release

OBJECTIVE

Customization of the rate of drug delivered based on individual patient requirements is of paramount importance in the design of drug delivery devices. Advances in manufacturing may enable multilayer drug delivery devices with different initial drug distributions in each layer. However, a robust mathematical understanding of how to optimize such capabilities is critically needed. The objective of this work is to determine the initial drug distribution needed in a spherical drug delivery device such as a capsule in order to obtain a desired drug release profile.

METHODS

This optimization problem is posed as an inverse mass transfer problem, and optimization is carried out using the solution of the forward problem. Both non-erodible and erodible multilayer spheres are analyzed. Cases with polynomial forms of initial drug distribution are also analyzed. Optimization is also carried out for a case where an initial burst in drug release rate is desired, followed by a constant drug release rate.

RESULTS

More than 60% reduction in root-mean-square deviation of the actual drug release rate from the ideal constant drug release rate is reported. Typically, the optimized initial drug distribution in these cases prevents or minimizes large drug release rate at early times, leading to a much more uniform drug release overall.

CONCLUSIONS

Results demonstrate potential for obtaining a desired drug delivery profile over time by carefully engineering the drug distribution in the drug delivery device. These results may help engineer devices that offer customized drug delivery by combining advanced manufacturing with mathematical optimization.

Formulation and characterization of immediate-release oral dosage forms with zolpidem tartrate fabricated by digital light processing (DLP) 3D printing technique

The introduction of three-dimensional (3D) printing in the pharmaceutical field has made great strides towards innovations in the way drugs are designed and manufactured. In this study, digital light processing (DLP) technique was used to fabricate oral dosage forms of different shapes with zolpidem tartrate (ZT), incorporated within its therapeutic range. Formulation factors, such as poly(ethylene glycol) diacrylate (PEGDA) and poly(ethylene glycol) 400 (PEG 400) ratio, as well as water content, were varied in combination with the surface area/volume (SA/V) ratio to achieve immediate drug release. Hypromellose (HPMC) was used as a stabilizing agent of photoreactive suspensions in an attempt to prevent drug sedimentation and subsequent variations in drug content uniformity. Oral dosage forms with doses in the range from 0.15 mg to 6.37 mg, showing very rapid and rapid drug dissolution, were successfully fabricated, confirming the potential of this technique in drug manufacturing with the ability to provide flexible dose adjustments and desirable release profiles by varying formulation factors and geometry of 3D models. DSC (differential scanning calorimetry), XRPD (X-ray powder diffraction) and scanning electron microscopy (SEM) showed that ZT remained in a crystalline form within printed dosage forms and no interactions were found between ZT and polymers.

Customized 3D-printed hollow capsular device filled with norfloxacin-loaded micropellets for controlled-release delivery

Pharmacotherapy has become more focused on the personalized treatment of patients with various diseases. This field of pharmacology and pharmacogenomics focuses on developing drug delivery systems designed to address the unique characteristics of individual patients. Three-dimensional printing technology can be used to fabricate personalized drug delivery systems with desired release properties according to patient needs. Norfloxacin (NOR)-loaded micropellets (MPs) were fabricated and filled inside a stereolithography (SLA) 3D printing technology-mediated hollow capsular device in accordance with a standard size of 09 (8.4 mm length × 2.70 mm diameter). The prepared 3D-printed hollow capsular device filled with pristine NOR and NOR-loaded MPs were characterized in terms of both in vitro and in vivo means. MPs with the particle size distribution of 1540.0 ± 26 µm showed 95.63 ± 2.0% NOR content with pellet-shaped surface morphology. The in vitro release profile showed an initial lag phase of approximately 30 min, followed by the sustained release of NOR from MPs from the 3D-printed hollow capsular device. The pharmacokinetic profile showed prolonged T_max, AUC, and evidence of good RBA of NOR compared to pure NOR after a single oral administration in the experimental animal model. The overall results confirm the feasibility of SLA-mediated 3D printing technology for preparing customized solid oral unit dosage carriers that can be filled with pure NOR- and NOR-loaded MPs with controlled-release delivery features.

Very-Rapidly Dissolving Printlets of Isoniazid Manufactured by SLS 3D Printing: In Vitro and In Vivo Characterization

The focus of this research was to understand the effects of formulation and processing variables on the very-rapidly dissolving printlets of isoniazid (INH) manufactured by the selective laser sintering (SLS) three-dimensional (3D) printing method, and to characterize their physicochemical properties, stability, and pharmacokinetics. Fifteen printlet formulations were manufactured by varying the laser scanning speed (400-500 mm/s, X₁), surface temperature (100-110 °C, X₂), and croscarmellose sodium (CCS, %, X₃), and the responses measured were weight (Y₁), hardness (Y₂), disintegration time (DT, Y₃), and dissolution (Y₄). Laser scanning was the most important processing factor affecting the responses. DT was very rapid (≥3 s), and dissolution (>99%) was completed within 3 min. The root-mean-square error in the studied responses was low and analysis of variance (ANOVA) was statistically significant (p < 0.05). X-ray micro-computed tomography (micro-CT) images showed very porous structures with 24.6-34.4% porosity. X-ray powder diffraction and differential scanning calorimetry data indicated partial conversion of the crystalline drug into an amorphous form. The printlets were stable at 40 °C/75% RH with no significant changes in assay and dissolution. Pharmacokinetic profiles of the printlets and compressed tablets were superimposable. In conclusion, the rapidly dissolving printlets of the INH were stable, and oral bioavailability was similar to that of compositionally identical compressed tablets.

Three-Dimensional (3D) Printing in Cancer Therapy and Diagnostics: Current Status and Future Perspectives

Three-dimensional (3D) printing is a technique where the products are printed layer-by-layer via a series of cross-sectional slices with the exact deposition of different cell types and biomaterials based on computer-aided design software. Three-dimensional printing can be divided into several approaches, such as extrusion-based printing, laser-induced forward transfer-based printing systems, and so on. Bio-ink is a crucial tool necessary for the fabrication of the 3D construct of living tissue in order to mimic the native tissue/cells using 3D printing technology. The formation of 3D software helps in the development of novel drug delivery systems with drug screening potential, as well as 3D constructs of tumor models. Additionally, several complex structures of inner tissues like stroma and channels of different sizes are printed through 3D printing techniques. Three-dimensional printing technology could also be used to develop therapy training simulators for educational purposes so that learners can practice complex surgical procedures. The fabrication of implantable medical devices using 3D printing technology with less risk of infections is receiving increased attention recently. A Cancer-on-a-chip is a microfluidic device that recreates tumor physiology and allows for a continuous supply of nutrients or therapeutic compounds. In this review, based on the recent literature, we have discussed various printing methods for 3D printing and types of bio-inks, and provided information on how 3D printing plays a crucial role in cancer management.

Microfluidic technology and its application in the point-of-care testing field

Since the outbreak of the coronavirus disease 2019 (COVID-19), countries around the world have suffered heavy losses of life and property. The global pandemic poses a challenge to the global public health system, and public health organizations around the world are actively looking for ways to quickly and efficiently screen for viruses. Point-of-care testing (POCT), as a fast, portable, and instant detection method, is of great significance in infectious disease detection, disease screening, pre-disease prevention, postoperative treatment, and other fields. Microfluidic technology is a comprehensive technology that involves various interdisciplinary disciplines. It is also known as a lab-on-a-chip (LOC), and can concentrate biological and chemical experiments in traditional laboratories on a chip of several square centimeters with high integration. Therefore, microfluidic devices have become the primary implementation platform of POCT technology. POCT devices based on microfluidic technology combine the advantages of both POCT and microfluids, and are expected to shine in the biomedical field. This review introduces microfluidic technology and its applications in combination with other technologies.

Additive Manufacturing Strategies for Personalized Drug Delivery Systems and Medical Devices: Fused Filament Fabrication and Semi Solid Extrusion

Novel additive manufacturing (AM) techniques and particularly 3D printing (3DP) have achieved a decade of success in pharmaceutical and biomedical fields. Highly innovative personalized therapeutical solutions may be designed and manufactured through a layer-by-layer approach starting from a digital model realized according to the needs of a specific patient or a patient group. The combination of patient-tailored drug dose, dosage, or diagnostic form (shape and size) and drug release adjustment has the potential to ensure the optimal patient therapy. Among the different 3D printing techniques, extrusion-based technologies, such as fused filament fabrication (FFF) and semi solid extrusion (SSE), are the most investigated for their high versatility, precision, feasibility, and cheapness. This review provides an overview on different 3DP techniques to produce personalized drug delivery systems and medical devices, highlighting, for each method, the critical printing process parameters, the main starting materials, as well as advantages and limitations. Furthermore, the recent developments of fused filament fabrication and semi solid extrusion 3DP are discussed. In this regard, the current state of the art, based on a detailed literature survey of the different 3D products printed via extrusion-based techniques, envisioning future directions in the clinical applications and diffusion of such systems, is summarized.

Application and Multi-Stage Optimization of Daylight Polymer 3D Printing of Personalized Medicine Products

Additive technologies have undoubtedly become one of the most intensively developing manufacturing methods in recent years. Among the numerous applications, the interest in 3D printing also includes its application in pharmacy for production of small batches of personalized drugs. For this reason, we conducted multi-stage pre-formulation studies to optimize the process of manufacturing solid dosage forms by photopolymerization with visible light. Based on tests planned and executed according to the design of the experiment (DoE), we selected the optimal quantitative composition of photocurable resin made of PEG 400, PEGDA MW 575, water, and riboflavin, a non-toxic photoinitiator. In subsequent stages, we adjusted the printer set-up and process parameters. Moreover, we assessed the influence of the co-initiators ascorbic acid or triethanolamine on the resin’s polymerization process. Next, based on an optimized formulation, we printed and analyzed drug-loaded tablets containing mebeverine hydrochloride, characterized by a gradual release of active pharmaceutical ingredient (API), reaching 80% after 6 h. We proved the possibility of reusing the drug-loaded resin that was not hardened during printing and determined the linear correlation between the volume of the designed tablets and the amount of API, confirming the possibility of printing personalized modified-release tablets.

3D Printing of a Graphene-Modified Photopolymer Using Stereolithography for Biomedical Applications: A Study of the Polymerization Reaction

Additive manufacturing is gaining importance thanks to its multiple advantages. Stereolithography (SLA) shows the highest accuracy and the lowest anisotropy, which has facilitated the emergence of new applications as dentistry or tissue engineering. However, the availability of commercial photopolymers is still limited, and there is an increasing interest in developing resins with properties adapted for these new applications. The addition of graphene-based nanomaterials (GBN) may provide interesting advantages, such as improved mechanical properties and bioactivity. However, there is a lack of knowledge regarding the effect of GBNs on the polymerization reaction. A photopolymerizable acrylic resin has been used, and the effect of the addition of 0.1wt% of graphene (G); graphene oxide (GO) and graphite nanoplatelets (GoxNP) on printability and polymerization have been investigated. It was observed that the effect depended on GBN type, functionalization and structure (e.g., number of layers, size, and morphology) due to differences in the extent of dispersion and light absorbance. The obtained results showed that GO and GoxNP did not significantly affect the printability and quality of the final structure, whilst the application of G exhibited a negative effect in terms of printability due to a reduction in the polymerization degree. GO and GoxNP-loaded resins showed a great potential to be used for manufacturing structures by SLA.

Stereolithography 3D printed implants: A preliminary investigation as potential local drug delivery systems to the ear

The current study is a preliminary investigation on the use of stereolithography 3D printing technology in the field of personalized medicines and specifically for delivering drugs locally, which can for example usefully be applied to ear infections. The main aim is the development of drug-loaded implants for the treatment of ear diseases, to improve patient compliance and to overcome the limitations of current delivery approaches. Multiple prototypes of implant geometries have been created and printed using a flexible resin containing 0.5% w/v of Levofloxacin. Physicochemical characterization of the printed implants was carried out using a variety of techniques (e.g., microscopic, spectroscopic, and mechanical analysis). Finally, preliminary in vitro tests were performed to evaluate the release profile of Levofloxacin, the prototype implant's stability, and their antimicrobial property. The results obtained show that there is no interaction between the resin and the drug, which is perfectly solubilized in the device. In addition, the results of the mechanical tests show that the material used resists compression without compromising the design itself, and the diffusion test has shown that the drug diffused through the matrix prototype at 50% over 3 weeks. The selected designs showed higher antimicrobial activity on E. coli than on S. aureus.

Translation of 3D printed materials for medical applications

During the past 30 years, 3D printing (3DP) technologies significantly influenced the manufacturing world, including innovation in biomedical devices. This special issue reviews recent advances in translating 3DP biomaterials and medical devices for metallic, ceramic, and polymeric devices, as well as bioprinting for organ and tissue engineering, along with regulatory issues in 3DP biomaterials. In our introductory article, besides introducing selected 3DP processes for biomaterials, current challenges and growth opportunities are also discussed. Finally, it highlights a few success stories for the 3D printed biomaterials for medical devices. We hope these articles will educate engineers, scientists, and clinicians about recent developments in translational 3DP technologies.

Stereolithography-assisted fabrication of 3D printed polymeric film for topical berberine delivery: in-vitro, ex-vivo and in-vivo investigations

OBJECTIVES

3D printed polymeric film intended for topical delivery of berberine (BBR) was developed using stereolithography (SLA) to enhance its local concentrations. PEGDMA was utilized as photopolymerizing resin, with PEG 400 as an inert component to facilitate BBR solubilization and permeation.

METHODS

Three batches of topical films were printed by varying resin and PEG 400 compositions. In-vitro physicochemical characterizations of the 3D printed films were performed using several analytical techniques including ex-vivo drug permeation studies. In-vivo skin irritation studies were also conducted to assess the skin irritation potential.

KEY FINDINGS

Films were 3D printed according to design specifications with minimal variations. Microscopic analysis confirmed 3D architecture, while thermal and X-ray diffraction studies revealed amorphous BBR entrapment. Drug permeation study showed effective ex-vivo diffusion up to 344.32 ± 61.20 µg/cm2 after 24.0 h possessing a higher ratio of PEG 400. In-vivo skin irritation studies have suggested the non-irritant nature of printed films.

CONCLUSIONS

Results indicated the suitability of SLA 3D printing for topical application in the treatment of skin diseases. The presence of PEG 400 in the printed 3D films facilitated BBR diffusion, resulting in an improved flux in ex-vivo model and non-irritant properties in vivo.

Smartphone-enabled 3D printing of medicines

3D printing is a manufacturing technique that is transforming numerous industrial sectors, particularly where it is key tool in the development and fabrication of medicinees that are personalised to the individual needs of patients. Most 3D printers are relatively large, require trained operators and must be located in a pharmaceutical setting to manufacture dosage forms. In order to realise fully the potential of point-of-care manufacturing of medicines, portable printers that are easy to operate are required. Here, we report the development of a 3D printer that operates using a mobile smartphone. The printer, operating on stereolithographic principles, uses the light from the smartphone's screen to photopolymerise liquid resins and create solid structures. The shape of the printed dosage form is determined using a custom app on the smartphone. Warfarin-loaded Printlets (3D printed tablets) of various sizes and patient-centred shapes (caplet, triangle, diamond, square, pentagon, torus, and gyroid lattices) were successfully printed to a high resolution and with excellent dimensional precision using different photosensitive resins. The drug was present in an amorphous form, and the Printlets displayed sustained release characterises. The promising proof-of-concept results support the future potential of this compact, user-friendly and interconnected smartphone-based system for point-of-care manufacturing of personalised medications.

Ascorbic acid-loaded polyvinyl alcohol/cellulose nanofibril hydrogels as precursors for 3D printed materials

We proposed a simple method to process hydrogels containing polyvinyl alcohol and cellulose nanofibrils (PVA/CNF) to prepare volumetric architectures by direct ink writing (DIW). The presence of CNF in the aqueous PVA suspensions conferred rheology profiles that were suitable for extrusion and solidification in pre-designed shapes. The viscoelastic behavior of the hybrid inks enabled precise control on processability and shape retention, for instance, as demonstrated in multilayered lattice structures of high fidelity. After lyophilization, the obtained 3D-printed hydrogels presented a very high porosity, with open and interconnected pores, allowing a high-water uptake capacity (up to 1600%). The mechanical strength of the composite 3D-printed materials matched those of soft tissues, opening opportunities for skin applications. As such, drug-loaded samples revealed a controlled and efficient delivery of an antioxidant (ascorbic acid) in PBS buffer media at 23 °C (~80% for 8 h). Altogether, PVA/CNF hydrogels were introduced as suitable precursors of 3D-lattice geometries with excellent physical and mechanical characteristics.

Hydrophilic Excipient-Independent Drug Release from SLA-Printed Pellets

Three-dimensional (3D) printing technology, specifically stereolithography (SLA) technology, has recently created exciting possibilities for the design and fabrication of sophisticated dosages for oral administration, paving a practical way to precisely manufacture customized pharmaceutical dosages with both personalized properties and sustained drug release behavior. However, the sustained drug release achieved in prior studies largely relies on the presence of hydrophilic excipients in the printing formulation, which unfortunately impedes the printability and formability of the corresponding printing formulations. The current study developed and prepared mini-sized oral pellets using the SLA technique and successfully accomplished a hydrophilic excipient-independent drug release behavior. With ibuprofen as the model drug, the customized photopolymerizable printing formulation included polyethylene glycol diacrylate (PEGDA) as a monomer and diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as a photoinitiator. The produced mini-sized pellets were thoroughly investigated for various factors, including their printability, physical properties, microscopic features, drug content, and drug-release profiles. The drug release profiles from the printed pellets that were larger size (3 mm and 6 mm) followed the Ritger–Peppas model, demonstrating that the release was influenced by both the diffusion of the dissolved drug and by the erosion of the hydrophilic excipients (PEG400). The profiles from the smaller printed pellets (1 mm and 2 mm) followed first release kinetics, not only illustrating that the release was impacted only by drug diffusion, but also indicating that there is a size boundary between the dependent and independent hydrophilic excipients. These results could create practical benefits to the pharmaceutical industry in terms of the design and development personalized dosages using the SLA printing technique with controllable drug release by manipulating size alone.

Characterization of Hydrophilic Polymers as a Syringe Extrusion 3D Printing Material for Orodispersible Film

The application of hydrophilic polymers in designing and three-dimensional (3D) printing of pharmaceutical products in various dosage forms has recently been paid much attention. Use of hydrophilic polymers and syringe extrusion 3D printing technology in the fabrication of orodispersible films (ODFs) might hold great potential in rapid drug delivery, personalized medicine, and manufacturing time savings. In this study, the feasibility of 3D-printed ODFs fabrication through a syringe extrusion 3D printing technique and using five different hydrophilic polymers (e.g., hydroxypropyl methylcellulose E15, hydroxypropyl methylcellulose E50, high methoxyl pectin, sodium carboxymethylcellulose, and hydroxyethylcellulose) as film-forming polymers and printing materials has been investigated. Rheology properties and printability of printing gels and physicochemical and mechanical properties of 3D-printed ODFs were evaluated. Amongst the investigated hydrophilic polymers, sodium carboxymethylcellulose at a concentration of 5% w/v (SCMC-5) showed promising results with a good printing resolution and accurate dimensions of the 3D-printed ODFs. In addition, SCMC-5 3D-printed ODFs exhibited the fastest disintegration time within 3 s due to high wettability, roughness and porosity on the surface. However, the results of the mechanical properties study showed that SCMC-5 3D printed ODFs were rigid and brittle, thus requiring special packaging to prevent them from any damage before practical use.

3D Printing of Thermo-Sensitive Drugs

Three-dimensional (3D) printing is among the rapidly evolving technologies with applications in many sectors. The pharmaceutical industry is no exception, and the approval of the first 3D-printed tablet (Spiratam^®) marked a revolution in the field. Several studies reported the fabrication of different dosage forms using a range of 3D printing techniques. Thermosensitive drugs compose a considerable segment of available medications in the market requiring strict temperature control during processing to ensure their efficacy and safety. Heating involved in some of the 3D printing technologies raises concerns regarding the feasibility of the techniques for printing thermolabile drugs. Studies reported that semi-solid extrusion (SSE) is the commonly used printing technique to fabricate thermosensitive drugs. Digital light processing (DLP), binder jetting (BJ), and stereolithography (SLA) can also be used for the fabrication of thermosensitive drugs as they do not involve heating elements. Nonetheless, degradation of some drugs by light source used in the techniques was reported. Interestingly, fused deposition modelling (FDM) coupled with filling techniques offered protection against thermal degradation. Concepts such as selection of low melting point polymers, adjustment of printing parameters, and coupling of more than one printing technique were exploited in printing thermosensitive drugs. This systematic review presents challenges, 3DP procedures, and future directions of 3D printing of thermo-sensitive formulations.

3D Printed Punctal Plugs for Controlled Ocular Drug Delivery

Dry eye disease is a common ocular disorder that is characterised by tear deficiency or excessive tear evaporation. Current treatment involves the use of eye drops; however, therapeutic efficacy is limited because of poor ocular bioavailability of topically applied formulations. In this study, digital light processing (DLP) 3D printing was employed to develop dexamethasone-loaded punctal plugs. Punctal plugs with different drug loadings were fabricated using polyethylene glycol diacrylate (PEGDA) and polyethylene glycol 400 (PEG 400) to create a semi-interpenetrating network (semi-IPN). Drug-loaded punctal plugs were characterised in terms of physical characteristics (XRD and DSC), potential drug-photopolymer interactions (FTIR), drug release profile, and cytocompatibility. In vitro release kinetics of the punctal plugs were evaluated using an in-house flow rig model that mimics the subconjunctival space. The results showed sustained release of dexamethasone for up to 7 days from punctal plugs made with 20% w/w PEG 400 and 80% w/w PEGDA, while punctal plugs made with 100% PEGDA exhibited prolonged releases for more than 21 days. Herein, our study demonstrates that DLP 3D printing represents a potential manufacturing platform for fabricating personalised drug-loaded punctal plugs with extended release characteristics for ocular administration.

Recent update of 3D printing technology in pharmaceutical formulation development

In modern world, Pharma sector observes steep increase in demand of personalized medicine. Various unique ideas and technology were proposed and implemented by different researchers to prepare personalized medicine and devices. 3-dimensional printing (3DP) is one of the revolutionary technologies which can be used to prepare tailored medicine via CAD (Computer Aided Design) software. 3DP allows researchers to manufacture customized dosage form with desired modifications in geometry which would in turn alter dosage behaviour of the product with reduced side effects. Current achievement of 3DP includes personalized and adjustable dosage form, multifunction drug delivery systems, medical devices, phantoms, and implants specific to patient anatomy. Additionally, 3DP is employed for preparing tailored regenerative medicines. This review focuses on 3DP use in pharmaceuticals including drug delivery systems and medical devices with their method of fabrication. Additionally, different clinical trials as well as different patents done till date are cited in the paper. Furthermore, regulatory issues and future perspective related to 3 D printing is also well discussed.