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

Fabrication of osmotic pump tablets utilizing semisolid extrusion three-dimensional printing technology

The utilization of three-dimensional (3D) printing technology is prevalent in the fabrication of oral sustained release preparations; however, there is a lack of research on 3D-printed osmotic pump tablets. A 3D-printed core-shell structure bezafibrate osmotic pump tablet was developed based on the characteristics of rapid absorption and short half-life of bezafibrate, utilizing semisolid extrusion (SSE) 3D printing technology. First, the properties of different shell materials were investigated to define the composition of the shell, and ultimately, the optimal formulation was found to be ethyl cellulose:cellulose acetate:polyethylene glycol = 2:1:2. The formulation of the tablet core was defined based on the printing performance and release behavior. The formulation consisted of bezafibrate, lactis anhydrous, sodium bicarbonate, sodium alginate, polyethylene oxide and sodium dodecyl sulfate at a ratio of 400:400:300:80:50:50. The tablet was capable of achieving zero-order release. The physicochemical properties were also characterized. The pharmacokinetic data analysis indicated that there were no statistically significant differences in the pharmacokinetic parameters between the 3D-printed tablets and the reference listed drugs. There was a strong correlation between the in vitro and in vivo results for the 3D-printed tablets. The results showed that SSE printing is a practical approach for manufacturing osmotic pump tablets.

Leveraging solid solubility and miscibility of etoricoxib in Soluplus® towards manufacturing of 3D printed etoricoxib tablets by additive manufacturing

This research focuses on exploring the solid solubility and miscibility of Etoricoxib, a poorly water-soluble anti-inflammatory drug, within Soluplus®, a polymer used as a matrix for 3D-printed tablets. By utilizing hot-melt extrusion (HME), the drug was dispersed within Soluplus® to enhance its solubility. The extrudates were then employed in 3D printing to create customized solid oral dosage form. This study's novelty lies in combining HME and 3D printing, aiming to improve drug incorporation, stability, and effectiveness in the final formulation. Comprehensive characterization techniques, including hot stage microscopy (HSM), scanning electron microscopy (SEM), micro-computed tomography (Micro-CT), florescence microscopy, optical microscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), solubility studies, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and aqueous solubility study were utilized to elucidate the physicochemical properties, thermal stability, and structural integrity for the extruded filaments (the printing ink), and 3D printed tablets made thereof. Furthermore, the in vitro drug release profile of the 3D printed tablet was systematically evaluated, revealing a controlled drug release pattern from the finished dosage form. The systematic investigation reported herein, starting from theoretical miscibility to the printing ink development through HME, detailed characterization of the extruded filaments, and further solid oral formulation development by additive manufacturing can be utilized as a platform technology or a pathway for the development of personalized medicine with drugs having similar physicochemical properties.

Microfabrication of controlled release osmotic drug delivery systems assembled from designed elements

BACKGROUND

This study investigates combining 3D printing with traditional compression methods to develop a multicomponent, controlled-release drug delivery system (DDS). The system uses osmotic tablet layers and a semipermeable membrane to control drug release, similar to modular Lego® structures.

METHODS

The DDS comprises two directly compressed tablet layers (push and pull) and a semipermeable membrane, all contained within a 3D-printed frame. The membrane is made from cellulose acetate and plasticizers like glycerol and propylene glycol. Various characterization techniques, including Positron Annihilation Lifetime Spectroscopy (PALS), were employed to evaluate microstructural properties, wettability, morphology, and drug dissolution.

RESULTS

Glycerol improved the membrane's wettability, as confirmed by PALS. The system achieved zero-order drug release, unaffected by stirring rates, due to the push and pull tablets within the 3D-printed frame. The release profile was stable, demonstrating effective drug delivery control.

CONCLUSION

The study successfully developed a prototype for a controlled-release osmotic DDS, achieving zero-order release kinetics for quinine hydrochloride after 2 h. This modular approach holds potential for personalized therapies in human and veterinary medicine, allowing customization at the point of care.

Current trends in 3D printed gastroretentive floating drug delivery systems: A comprehensive review

Gastrointestinal (GI) environment is influenced by several factors (gender, genetics, sex, disease state, food) leading to oral drug absorption variability or to low bioavailability. In this scenario, gastroretentive drug delivery systems (GRDDS) have been developed in order to solve absorption problems, to lead to a more effective local therapy or to allow sustained drug release during a longer time period than the typical oral sustained release dosage forms. Among all GRDDS, floating systems seem to provide a promising and practical approach for achieving a long intra-gastric residence time and sustained release profile. In the last years, a novel technique is being used to manufacture this kind of systems: three-dimensional (3D) printing technology. This technique provides a versatile and easy process to manufacture personalized drug delivery systems. This work presents a systematic review of the main 3D printing based designs proposed up to date to manufacture floating systems. We have also summarized the most important parameters involved in buoyancy and sustained release of the systems, in order to facilitate the scale up of this technology to industrial level. Finally, a section discussing about the influence of materials in drug release, their biocompatibility and safety considerations have been included.

Extrusion-based 3D printing for development of complex capsular systems for advanced drug delivery

This review explores the feasibility of extrusion-based 3D printing techniques for producing complex dosage forms (such as capsular shells/devices) that provide controlled drug release and targeted delivery. The current discussion explores how extrusion-based 3D printing techniques, particularly Fused Deposition Modelling (FDM) and Pressure-Assisted Modelling (PAM), offer significant advantages in fabricating such complex dosage forms. This technology enables the fabrication of single-, dual-, or multi-compartment capsular systems with customized designs/geometry of the capsular shell to achieve delayed, sustained, or pulsatile drug release. The impact of customized design/geometry on the biopharmaceutical performances of loaded therapeutics is comprehensively discussed. The potential of 3D printing techniques for different specialized drug delivery purposes like gastric floating, implants, suppositories, and printfills are also addressed. This technique has the potential to significantly improve the therapeutic outcomes, and patient adherence to medication regimens, and pave the way for personalized medicine.

Fabrication of Polypill Pharmaceutical Dosage Forms Using Fused Deposition Modeling 3D Printing: A Systematic Review

BACKGROUND/OBJECTIVES

The pharmacy profession has undergone significant changes driven by advancements in patient care and healthcare systems. The FDA approval of Spritam® (levetiracetam), the first 3D-printed drug, has sparked increased interest in the use of Fused Deposition Modeling (FDM) 3D printing for pharmaceutical applications, particularly in the production of polypills.

METHODS

This review provides an overview of FDM 3D printing in the development of pharmaceutical dosage forms, focusing on its operation, printing parameters, materials, additives, advantages, and limitations. Key aspects, such as the ability to personalize medication and the challenges associated with the technique, including drug stability at high temperatures, are discussed.

RESULTS

Fourteen studies relevant to FDM 3D-printed polypills were analyzed from an initial pool of 60. The increasing number of publications highlights the growing global interest in this technology, with the UK contributing the highest number of studies.

CONCLUSIONS

FDM 3D printing offers significant potential for personalized medicine by enabling precise control over dosage forms and tailoring treatments to individual patient needs. However, limitations such as high printing temperatures and the lack of standardized GMP guidelines for large-scale production must be addressed to fully realize its potential in pharmaceutical manufacturing.

Ultrasound-compatible 3D-printed Franz diffusion system for sonophoresis with microbubbles

Sonophoresis is a topical drug delivery approach that utilises ultrasound as a physical stimulus to enhance permeation of active pharmaceutical ingredients through the skin. Only limited research has however been conducted to evaluate the potential of ultrasound-responsive drug carriers, such as gas microbubbles, in sonophoresis. Franz diffusion cells have been extensively used for measuring drug permeation in vitro; however, traditional systems lack compatibility with ultrasound and only limited characterisation of their acoustical behaviour has been carried out in previous research. To overcome this limitation, we designed and manufactured a novel Franz cell donor compartment coupled with a conventional glass receptor, and performed a functional characterisation of the assembly for application in sonophoresis with ultrasound-responsive agents (specifically imiquimod-loaded gas microbubbles). The donor was fabricated using a photoreactive resin via 3D printing and was designed to enable integration with a therapeutically relevant ultrasound source. The assembly was capable of effectively retaining liquids during prolonged incubation and the absorption of imiquimod onto the 3D-printed material was comparable to the one of glass. Moreover, a predictable ultrasound field could be generated at a target surface without any significant spatial distortion. Finally, we demonstrated applicability of the developed assembly in sonophoresis experiments with StratM®, wherein ultrasound stimulation in the presence of microbubbles resulted in significantly enhanced drug permeation through and partitioning within the membrane (2.96 ± 0.25 μg and 3.84 ± 0.39 μg) compared to passive diffusion alone (1.74 ± 0.29 μg and 2.29 ± 0.32 μg), over 24 h.

Review on Recent Advance of 3DP-Based Pediatric Drug Formulations

Three-dimensional printing (3DP) has emerged as a game-changing technology in the pharmaceutical industry, providing novel formulation development in the pharmaceutical sector as a whole, which improved patients' individualized therapy. The pediatric population is among the key targets for individualized therapy. Children are a diverse group that includes neonates, infants, and toddlers, each with unique physiological characteristics. Treatment adherence has a significant impact on safe and effective pharmacotherapy in the pediatric population. Improvement of therapeutic dosage forms that provide for the special demands of the pediatric population is a significant challenge for the pharmaceutical industry. Scientists have actively explored 3DP, a quick prototype manufacturing method that has emerged in recent years from many occupations due to its benefits of modest operation, excellent reproducibility, and vast adaptability. This review illuminates the most widely used 3DP technology and its application in the development of pediatric-friendly drug formulations. This 3DP technology allows optimization of pediatric dosage regimens and cases that require individualized treatment, such as geriatrics, renal impairment, liver impairment, critically ill, pregnancy populations, and drugs with nonlinear pharmacokinetics. The fast evolution of 3DP expertise, in addition to the introduction of pharmaceutical inks, has enormous promise for patient dosage form customization.

Revolutionizing Ophthalmic Care: A Review of Ocular Hydrogels from Pathologies to Therapeutic Applications

PURPOSE

This comprehensive review is designed to elucidate the transformative role and multifaceted applications of ocular hydrogels in contemporary ophthalmic therapeutic strategies, with a particular emphasis on their capability to revolutionize drug delivery mechanisms and optimize patient outcomes.

METHODS

A systematic and structured methodology is employed, initiating with a succinct exploration of prevalent ocular pathologies and delineating the corresponding therapeutic agents. This serves as a precursor for an extensive examination of the diverse methodologies and fabrication techniques integral to the design, development, and application of hydrogels specifically tailored for ophthalmic pharmaceutical delivery. The review further scrutinizes the pivotal manufacturing processes that significantly influence hydrogel efficacy and delves into an analysis of the current spectrum of hydrogel-centric ocular formulations.

RESULTS

The review yields illuminating insights into the escalating prominence of ocular hydrogels within the medical community, substantiated by a plethora of ongoing clinical investigations. It reveals the dynamic and perpetually evolving nature of hydrogel research and underscores the extensive applicability and intricate progression of transposing biologics-loaded hydrogels from theoretical frameworks to practical clinical applications.

CONCLUSIONS

This review accentuates the immense potential and promising future of ocular hydrogels in the realm of ophthalmic care. It not only serves as a comprehensive guide but also as a catalyst for recognizing the transformative potential of hydrogels in augmenting drug delivery mechanisms and enhancing patient outcomes. Furthermore, it draws attention to the inherent challenges and considerations that necessitate careful navigation by researchers and clinicians in this progressive field.

Preparation and Stability Study of an Injectable Hydrogel for Artificial Intraocular Lenses

Currently available intraocular lenses (IOLs) on the market often differ significantly in elastic modulus compared to the natural human lens, which impairs their ability to respond effectively to the tension of the ciliary muscles for focal adjustment after implantation. In this study, we synthesized a polyacrylamide-sodium acrylate hydrogel (PAH) through the cross-linking polymerization of acrylamide and sodium acrylate. This hydrogel possesses excellent biocompatibility and exhibits several favorable properties. Notably, the hydrogel demonstrates high transparency (94%) and a refractive index (1.41 ± 0.07) that closely matches that of the human lens (1.42). Additionally, it shows strong compressive strength (14.00 kPa), good extensibility (1400%), and an appropriate swelling ratio (50 ± 2.5%). Crucially, the tensile modulus of the hydrogel is 2.07 kPa, which closely aligns with the elastic modulus of the human lens (1.70-2.10 kPa), enabling continuous focal adjustment under the tension exerted by the ciliary muscles.

Additive manufacturing of TPU devices for genital herpes treatment with sustained acyclovir release

The treatment of recurrent genital herpes typically involves daily doses of acyclovir for extended periods. Additive manufacturing is an intriguing technique for creating personalised drug delivery systems, which can enhance the effectiveness of treatments for various diseases. The vaginal route offers a viable alternative for the systemic administration of drugs with low oral bioavailability. In this study, we produced different grades of thermoplastic polyurethane (TPU) filaments through hot-melt extrusion, with acyclovir concentrations of 0%, 10%, and 20% by weight. We used fused filament fabrication to manufacture matrix-based devices, including intrauterine devices and intravaginal rings. Our results, obtained through SEM, FTIR, and DSC analyses, confirm the successful incorporation of acyclovir into the matrix. Thermal analysis reveals that the manufacturing process alters the organization of the TPU chains, resulting in a slight reduction in crystallinity. In our in-vitro tests, we observed an initial burst release on the first day, followed by sustained release at reduced rates for up to 145 days, demonstrating their potential for long-term applications. Additionally, cytotoxicity analysis suggests the excellent biocompatibility of the printed devices, and biological assays show a remarkable 99% reduction in HSV-1 replication. In summary, TPU printed devices offer a promising alternative for long-term genital herpes treatment, with the results obtained potentially contributing to the advancement of pharmaceutical manufacturing.

3D printed scaffolds as delivery devices for nanocrystals: A proof of concept loading Atorvastatin with enhanced properties for sublingual route of administration

Increasing the solubility of drugs is a recurrent objective of pharmaceutical research, and one of the most widespread strategies today is the formulation of nanocrystals (NCs). Beyond the many advantages of formulating NCs, their incorporation into solid dosage forms remains a challenge that limits their use. In this work, we set out to load Atorvastatin NCs (ATV-NCs) in a delivery device by combining 3D scaffolds with an "in situ" loading method such as freeze-drying. When comparing two infill patterns for the scaffolds at two different percentages, the one with the highest NCs load was chosen (Gyroid 20 % infill pattern, 13.8 ± 0.5 mg). Colloidal stability studies of NCs suggest instability in acidic media, and therefore, the system is postulated for use as a sublingual device, potentially bypassing stomach and hepatic first-pass effects. An ad hoc dissolution device was developed to mimic the release of actives. The nanometric size and properties acquired in the process were maintained, mainly in the dissolution rate and speed, achieving 100 % dissolution of the content in 180 s. Based on these results, the proof of concept represents an innovative approach to converting NCs suspensions into solid dosage forms.

(3D) Bioprinting-Next Dimension of the Pharmaceutical Sector

To create a review of the published scientific literature on the benefits and potential perspectives of the use of 3D bio-nitrification in the field of pharmaceutics. This work was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting meta-analyses and systematic reviews. The scientific databases PubMed, Scopus, Google Scholar, and ScienceDirect were used to search and extract data using the following keywords: 3D bioprinting, drug research and development, personalized medicine, pharmaceutical companies, clinical trials, drug testing. The data points to several aspects of the application of bioprinting in pharmaceutics were reviewed. The main applications of bioprinting are in the development of new drug molecules as well as in the preparation of personalized drugs, but the greatest benefits are in terms of drug screening and testing. Growth in the field of 3D printing has facilitated pharmaceutical applications, enabling the development of personalized drug screening and drug delivery systems for individual patients. Bioprinting presents the opportunity to print drugs on demand according to the individual needs of the patient, making the shape, structure, and dosage suitable for each of the patient's physical conditions, i.e., print specific drugs for controlled release rates; print porous tablets to reduce swallowing difficulties; make transdermal microneedle patches to reduce patient pain; and so on. On the other hand, bioprinting can precisely control the distribution of cells and biomaterials to build organoids, or an Organ-on-a-Chip, for the testing of drugs on printed organs mimicking specified disease characteristics instead of animal testing and clinical trials. The development of bioprinting has the potential to offer customized drug screening platforms and drug delivery systems meeting a range of individualized needs, as well as prospects at different stages of drug development and patient therapy. The role of bioprinting in preclinical and clinical testing of drugs is also of significant importance in terms of shortening the time to launch a medicinal product on the market.

Expanding the Manufacturing Approaches for Gastroretentive Drug Delivery Systems with 3D Printing Technology

Gastroretentive drug delivery systems (GRDDSs) have gained substantial attention in the last 20 years due to their ability to retain the drug in the stomach for an extended time, thus promoting an extended release and high bioavailability for a broad range of active pharmaceutical ingredients (APIs) that are pH-sensitive and/or have a narrow absorption window. The currently existing GRDDSs include floating, expanding, mucoadhesive, magnetic, raft-forming, ion-exchanging, and high-density systems. Although there are seven types of systems, the main focus is on floating, expanding, and mucoadhesive systems produced by various techniques, 3D printing being one of the most revolutionary and currently studied ones. This review assesses the newest production technologies and briefly describes the in vitro and in vivo evaluation methods, with the aim of providing a better overall understanding of GRDDSs as a novel emerging strategy for targeted drug delivery.

Unveiling the Drug Formulation Code: A Journey to Three-Dimensional Precision

Magistral formulations emerged years ago and were of great help in the personalization of treatments for patients. Over time, innovation began in this area with new technologies such as three-dimensional (3D) printing, which has brought greater benefits, ease of preparation, new scopes, and even cost reduction. Three-dimensional printing of medicines opened the way to create personalized multi-dose, controlled-release, multi-drug tablets, among others. In addition, this technology manages to be more specific in adjusting pharmacokinetics, doses, and even organoleptic qualities, which is precisely what is sought since the medication is being personalized for a patient due to a particular case or condition. Throughout the research, some studies can be observed that function as a base that provides safety and effectiveness for the subsequent use of other pharmaceuticals in the 3D printing of medicines.

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.

Trend of pharmaceuticals 3D printing in the Middle East and North Africa (MENA) region: An overview, regulatory perspective and future outlook

The traditional method of producing medicine using the "one-size fits all" model is becoming a major issue for pharmaceutical manufacturers due to its inability to produce customizable medicines for individuals' needs. Three-dimensional (3D) printing is a new disruptive technology that offers many benefits to the pharmaceutical industry by revolutionizing the way pharmaceuticals are developed and manufactured. 3D printing technology enables the on-demand production of personalized medicine with tailored dosage, shape and release characteristics. Despite the lack of clear regulatory guidance, there is substantial interest in adopting 3D printing technology in the large-scale manufacturing of medicine. This review aims to evaluate the research efforts of 3D printing technology in the Middle East and North Africa (MENA) region, with a particular emphasis on pharmaceutical research and development. Our analysis indicates an upsurge in the overall research activity of 3D printing technology but there is limited progress in pharmaceuticals research and development. While the MENA region still lags, there is evidence of the regional interest in expanding the 3D printing technology applications in different sectors including pharmaceuticals. 3D printing holds great promise for pharmaceutical development within the MENA region and its advancement will require a strong collaboration between academic researchers and industry partners in parallel with drafting detailed guidelines from regulatory authorities.

Research progress of photo-crosslink hydrogels in ophthalmology: A comprehensive review focus on the applications

Hydrogel presents a three-dimensional polymer network with high water content. Over the past decade, hydrogel has developed from static material to intelligent material with controllable response. Various stimuli are involved in the formation of hydrogel network, among which photo-stimulation has attracted wide attention due to the advantages of controllable conditions, which has a good application prospect in the treatment of ophthalmic diseases. This paper reviews the application of photo-crosslink hydrogels in ophthalmology, focusing on the types of photo-crosslink hydrogels and their applications in ophthalmology, including drug delivery, tissue engineering and 3D printing. In addition, the limitations and future prospects of photo-crosslink hydrogels are also provided.

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.

Programmable and Modularized Gas Sensor Integrated by 3D Printing

The rapid advancement of intelligent manufacturing technology has enabled electronic equipment to achieve synergistic design and programmable optimization through computer-aided engineering. Three-dimensional (3D) printing, with the unique characteristics of near-net-shape forming and mold-free fabrication, serves as an effective medium for the materialization of digital designs into usable devices. This methodology is particularly applicable to gas sensors, where performance can be collaboratively optimized by the tailored design of each internal module including composition, microstructure, and architecture. Meanwhile, diverse 3D printing technologies can realize modularized fabrication according to the application requirements. The integration of artificial intelligence software systems further facilitates the output of precise and dependable signals. Simultaneously, the self-learning capabilities of the system also promote programmable optimization for the hardware, fostering continuous improvement of gas sensors for dynamic environments. This review investigates the latest studies on 3D-printed gas sensor devices and relevant components, elucidating the technical features and advantages of different 3D printing processes. A general testing framework for the performance evaluation of customized gas sensors is proposed. Additionally, it highlights the superiority and challenges of programmable and modularized gas sensors, providing a comprehensive reference for material adjustments, structure design, and process modifications for advanced gas sensor devices.

Artificial Intelligence-Based 3D Printing Strategies for Bone Scaffold Fabrication and Its Application in Preclinical and Clinical Investigations

3D printing has become increasingly popular in the field of bone tissue engineering. However, the mechanical properties, biocompatibility, and porosity of the 3D printed bone scaffolds are major requirements for tissue regeneration and implantation as well. Designing the scaffold architecture in accordance with the need to create better mechanical and biological stimuli is necessary to achieve unique scaffold properties. To accomplish this, different 3D designing strategies can be utilized with the help of the scaffold design library and artificial intelligence (AI). The implementation of AI to assist the 3D printing process can enable it to predict, adapt, and control the parameters on its own, which lowers the risk of errors. This Review emphasizes 3D design and fabrication of bone scaffold using different materials and the use of AI-aided 3D printing strategies. Also, the adaption of AI to 3D printing helps to develop patient-specific scaffolds based on different requirements, thus providing feedback and adequate data for reproducibility, which can be improvised in the future. These printed scaffolds can also serve as an alternative to preclinical animal test models to cut costs and prevent immunological interference.

Rising role of 3D-printing in delivery of therapeutics for infectious disease

Modern drug delivery to tackle infectious disease has drawn close to personalizing medicine for specific patient populations. Challenges include antibiotic-resistant infections, healthcare associated infections, and customizing treatments for local patient populations. Recently, 3D-printing has become a facilitator for the development of personalized pharmaceutic drug delivery systems. With a variety of manufacturing techniques, 3D-printing offers advantages in drug delivery development for controlled, fine-tuned release and platforms for different routes of administration. This review summarizes 3D-printing techniques in pharmaceutics and drug delivery focusing on treating infectious diseases, and discusses the influence of 3D-printing design considerations on drug delivery platforms targeting these diseases. Additionally, applications of 3D-printing in infectious diseases are summarized, with the goal to provide insight into how future delivery innovations may benefit from 3D-printing to address the global challenges in infectious disease.

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.

Recent advances in lignin-based 3D printing materials: A mini-review

With the growing global population and rapid economic development, the demand for energy and raw materials is increasing, and the supply of fossil resources as the main source of energy and raw materials has reached a critical juncture. However, our overexploitation and overconsumption of fossil resources have led to serious problems, including environmental pollution, climate change, and ecosystem destruction. In the face of these challenges, we must recognize the negative impacts of the shortage of fossil resources and actively seek sustainable alternative sources of energy and resources to protect our environment and sustainable development in the future. Three-dimensional (3D) printing, an additive manufacturing technology, has been used in many fields to manufacture complex and high-precision products. While traditional manufacturing processes typically produce large amounts of waste and emissions that are harmful to the environment, 3D printing is much more energy efficient compared to traditional manufacturing methods, which helps to lower energy costs and reduce reliance on non-renewable energy sources. The development of low-carbon and environmentally friendly 3D printing materials can help to reduce carbon emissions and environmental pollution and realize the goal of sustainable development. Lignin, as the second largest renewable green biomass resource after cellulose, has great potential for manufacturing low-carbon and environmentally friendly 3D printing materials. This review presents some recent studies on the applications of lignin and its derivatives in photo-curing 3D printing, including the preparation and performance of lignin-based photosensitive prepolymers, lignin-based reactive diluents, lignin-based photo-initiators, and lignin-based additive. This review also provides recent studies on the preparation and performance of lignin-based thermoplastic polymer for Fused Deposition Modeling (FDM) 3D printing. Finally, the future challenges and industrialization prospects of lignin-based 3D printing materials are discussed.

Fabrication of 3D Printed, Core-and-Shell Implants as Controlled Release Systems for Local siRNA Delivery

The development and clinical translation of small interfering RNA (siRNA) therapies remains challenging owing to their poor pharmacokinetics. 3D printing technology presents a great opportunity to fabricate personalized implants for local and sustained delivery of siRNA. Hydrogels can mimic the mechanical properties of tissues, avoiding the problems associated with rigid implants. Herein, a thermoresponsive composite hydrogel suitable for extrusion 3D-printing is formulated to fabricate controlled-release implants loaded with siRNA-Lipofectamine RNAiMAX complexes. A hydrogel matrix mainly composed of uncharged agarose to protect siRNA from decomplexation is selected. Additionally, pluronic F127 and gelatin are added to improve the printability, degradation, and cell adhesion to the implants. To avoid exposing siRNA to thermal stress during the printing process, a core-and-shell design is set up for the implants in which a core of siRNA-complexes loaded-pluronic F127 is printed without heat and enclosed with a shell comprising the thermoresponsive composite hydrogel. The release profile of siRNA-complexes is envisioned to be controlled by varying the printing patterns. The results reveal that the implants sustain siRNA release for one month. The intactness of the released siRNA-complexes is proven until the eighth day. Furthermore, by changing the printing patterns, the release profiles can be tailored.

Polypill and Combination Therapy: Blood Pressure and Cardiovascular Risk Reduction

PURPOSE OF REVIEW

The number of medications prescribed to patients has been progressively increasing, primarily driven by cardioprotective medications. The advent of pharmaceutical 3D printing technology holds the promise of reducing the burden of multiple pills by combining various medications with different release mechanisms into a single tablet. This development encourages a comprehensive review of the evidence supporting the use of combination pills.

RECENT FINDINGS

Recent randomized studies have shown higher BP control rates in quadpill groups than in monotherapy groups and improved 6-month BP control rates with a low-dose triple fixed-dose combination (FDC) medication compared to usual care. Recent randomized controlled trials also support FDC use for primary and secondary prevention of cardiovascular disease. Three-dimensional printing technologies such as powder-based (PB) 3D printing, fused deposition modeling (FDM) 3D printing, and semisolid extrusion (EXT) 3D printing are examples of promising technologies that could be utilized to combine multiple medications with different release mechanisms into a single tablet. FDC therapy can provide patients with combination regimens with a reduced pill burden, which promotes improved adherence and efficacy. Recent randomized trials have shown that FDC can be used for primary and secondary prevention of cardiovascular disease with no significant difference in adverse events. Multidisciplinary approaches should be implemented to enhance long-term adherence, and further research on establishing affordable and effective initial dual antihypertensive therapy options is necessary. Pharmaceutical 3D printing technology may play an important role in enhancing the flexibility, affordability, and feasibility of clinical FDC utilization.

Exploring Environmental Settings to Improve the Printability of Paroxetine-Loaded Filaments by Fused Deposition Modelling

The successful integration of hot-melt extrusion (HME) and fused deposition modelling (FDM) depends on a better understanding of the impact of environmental conditions on the printability of formulations, since they significantly affect the properties of the raw materials, whose control is crucial to enable three-dimensional printing (3DP). Hence, the objective of this work was to investigate the correlation between the environmental settings and the properties of paroxetine (PRX)-loaded filaments, previously produced by HME, which affect printability by FDM. The influence of different drying methods of the physical mixtures (PMs) and HME-filaments (FILs) on the quality and printability of these products was also assessed. The printability of FILs was evaluated in terms of the water content, and the mechanical and thermal properties of the products. Stability studies and physicochemical, thermal, and in vitro dissolution tests were carried out on the 3D-printed tablets. Stability studies demonstrated the high ductility of the PRX loaded FILs, especially under high humidity conditions. Under low humidity storage conditions (11% RH), the FILs became stiffer and were successfully used to feed the FDM printer. Water removal was slow when carried out passively in a controlled atmosphere (desiccator) or accelerated by using active drying methods (heat or microwave). Pre-drying of the PRX/excipients and/or PMs did not show any positive effect on the printability of the FIL. On the contrary, dry heat and, preferably, microwave mediated drying processes were shown to reduce the holding time required for successful FDM printing, enabling on-demand production at the point of care.

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.

Multifunctional Microneedle Patches via Direct Ink Drawing of Nanocomposite Inks for Personalized Transdermal Drug Delivery

Additive manufacturing, commonly known as 3D printing, allows decentralized drug fabrication of orally administered tablets. Microneedles are comparatively favorable for self-administered transdermal drug delivery with improved absorption and bioavailability. Due to the cross-scale geometric characteristics, 3D-printed microneedles face a significant trade-off between the feature resolution and production speed in conventional layer-wise deposition sequences. In this study, we introduce an economical and scalable direct ink drawing strategy to create drug-loaded microneedles. A freestanding microneedle is efficiently generated upon each pneumatic extrusion and controlled drawing process. Sharp tips of ∼5 μm are formed with submillimeter nozzles, representing 2 orders of magnitude improved resolution. As the key enabler of this fabrication strategy, the yield-stress fluid inks are formulated by simply filling silica nanoparticles into regular polymer solutions. The approach is compatible with various microneedles based on dissolvable, biodegradable, and nondegradable polymers. Various matrices are readily adopted to adjust the release behaviors of the drug-loaded microneedles. Successful fabrication of multifunctional patches with heterogeneously integrated microneedles allows the treatment of melanoma via synergistic photothermal therapy and combination chemotherapy. The personalized patches are designed for cancer severity to achieve high therapeutic efficacy with minimal side effects. The direct ink drawing reported here provides a facile and low-cost fabrication strategy for multifunctional microneedle patches for self-administering transdermal drug delivery.

Development of Subdermal Implants Using Direct Powder Extrusion 3D Printing and Hot-Melt Extrusion Technologies

Implants are drug delivery platforms that consist of a drug-polymer matrix with the ability of providing a localized and efficient controlled release of the drug with minimal side effects and achievement of the desired therapeutic outcomes with low drug loadings. Direct powder extrusion (DPE) 3D printing technology involves the extrusion of material through a nozzle of the printer in the form of pellets or powder. The present study aimed at investigating the use of the CELLINK BIO X™ bioprinter using DPE 3D printing technique to fabricate and evaluate the impact of different shapes (cuboid, cylinder, and tube) of raloxifene hydrochloride (RFH)-loaded subdermal implants on the release of RFH from the implants. This study further evaluated the impact of different processing techniques, viz., hot-melt extrusion (HME) technology vs. DPE 3D printing technique, on the release of RFH from the implants fabricated by each processing technique. All the fabricated implants were characterized by XRD, DSC, SEM, and FTIR, and evaluated for their water uptake, mass loss, and in vitro RFH release. The current study successfully demonstrated a great opportunity of controlling and/or tuning the release of RFH from the subdermal implants by altering the implant shape, and hence surface area, and could be a great contribution and/or addition to the personalization of medicines and improvement of patient compliance.

Unidirectional drug release from 3D printed personalized buccal patches using FDM technology

Oromucosal delivery of active ingredients of drugs provides a superior administration route for the treatment of oral diseases, due to avoidance of the first pass effect. In the present work, in view of the characteristics of large differences between oral ulcer symptoms and different lesion sizes, dexamethasone acetate unidirectional drug release buccal patches has been prepared based on Fused Deposition Modelling (FDM). Unidirectional drug release was achieved by covering the top and side with ethyl cellulose. Polyvinyl alcohol as a drug carrier, xylitol as a plasticizer. First, the protection effect of different thicknesses of the protective layer is investigated to determine the thickness of the protective layer. Co-extrusion printing method was adapted, utilizing blank filament to regulate preparations with different areas' drug loading. The results show that co-extrusion had no significant impact on the overall patches' drug release and adhesion properties. The physicochemical properties of the patches were also characterized. Evaluation of irritation is showed that these patches do not cause irritation to the oral mucosa of rats. Pharmacodynamic evaluation results showed that the preparation could promote the reduction of ulcer area. The results showed that FDM printing is a convenient and practical approach in manufacturing buccal patches.

Design of experiment and machine learning inform on the 3D printing of hydrogels for biomedical applications

In the biomedical field, 3D printing has the potential to deliver on some of the promises of personalized therapy, notably by enabling point-of-care fabrication of medical devices, dosage forms and bioimplants. To achieve this full potential, a better understanding of the 3D printing processes is necessary, and non-destructive characterization methods must be developed. This study proposes methodologies to optimize the 3D printing parameters for soft material extrusion. We hypothesize that combining image processing with design of experiment (DoE) analyses and machine learning could help obtaining useful information from a quality-by-design perspective. Herein, we investigated the impact of three critical process parameters (printing speed, printing pressure and infill percentage) on three critical quality attributes (gel weight, total surface area and heterogeneity) monitored with a non-destructive methodology. DoE and machine learning were combined to obtain information on the process. This work paves the way for a rational approach to optimize 3D printing parameters in the biomedical field.

Three-Dimensionally Printed Vaginal Rings: Perceptions of Women and Gynecologists in a Cross-Sectional Survey

Three-dimensional printing technologies can be implemented for the fabrication of personalized vaginal rings (VRs) as an alternative approach to traditional manufacturing. Although several studies have demonstrated the potential of additive manufacturing, there is a lack of knowledge concerning the opinions of patients and clinicians. This study aimed to investigate the perception of women and gynecologists regarding VRs with personalized shapes. The devices were printed with different designs (traditional, "Y", "M", and flat circle) by Fused Deposition Modeling for a cross-sectional survey with 155 participants. Their anticipated opinion was assessed through a questionnaire after a visual/tactile analysis of the VRs. The findings revealed that most women would feel comfortable using some of the 3D-printed VR designs and demonstrated good acceptability for the traditional and two innovative designs. However, women presented multiple preferences when the actual geometry was assessed, which directly related to their age, previous use of the vaginal route, and perception of comfort. In turn, gynecologists favored prescribing traditional and flat circle designs. Overall, although there was a difference in the perception between women and gynecologists, they had a positive opinion of the 3D-printed VRs. Finally, the personalized VRs could lead to an increase in therapeutic adherence, by meeting women's preferences.

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.

Mechanically promoted lipid-based filaments via composition tuning for extrusion-based 3D-printing

Lipid excipients are favorable materials in pharmaceutical formulations owing to their natural, biodegradable, low-toxic and solubility/permeability enhancing properties. The application of these materials with advanced manufacturing platforms, particularly filament-based 3D-printing, is attractive for personalized manufacturing of thermolabile drugs. However, the filament's weak mechanical properties limit their full potential. In this study, highly flexible filaments were extruded using PG6-C16P, a lipid-based excipient belonging to the group of polyglycerol esters of fatty acids (PGFAs), based on tuning the ratio between its major and minor composition fractions. Increasing the percentage of the minor fractions in the system was found to enhance the relevant mechanical filament properties by 50-fold, guaranteeing a flawless 3D-printability. Applying a novel liquid feeding approach further improved the mechanical filament properties at lower percentage of minor fractions, whilst circumventing the issues associated with the standard extrusion approach such as low throughput. Upon drug incorporation, the filaments retained high mechanical properties with a controlled drug release pattern. This work demonstrates PG6-C16 P as an advanced lipid-based material and a competitive printing excipient that can empower filament-based 3D-printing.

Customizable 3D Printed Implants Containing Triamcinolone Acetonide: Development, Analysis, Modification, and Modeling of Drug Release

Three-dimensional-printed customizable drug-loaded implants provide promising opportunities to improve the current therapy options. In this study, we present a modular implant in which shape, dosage, and drug release can be individualized independently of each other to patient characteristics to improve parenteral therapy with triamcinolone acetonide (TA) over three months. This study focused on the examination of release modification via fused deposition modeling and subsequent prediction. The filaments for printing consisted of TA, ethyl cellulose, hypromellose, and triethyl citrate. Two-compartment implants were successfully developed, consisting of a shape-adaptable shell and an embedded drug-loaded network. For the network, different strand widths and pore size combinations were printed and analyzed in long-term dissolution studies to evaluate their impact on the release performance. TA release varied between 8.58 ± 1.38 mg and 21.93 mg ± 1.31 mg over three months depending on the network structure and the resulting specific surface area. Two different approaches were employed to predict the TA release over time. Because of the varying release characteristics, applicability was limited, but successful in several cases. Using a simple Higuchi-based approach, good release predictions could be made for a release time of 90 days from the release data of the initial 15 days (RMSEP ≤ 3.15%), reducing the analytical effort and simplifying quality control. These findings are important to establish customizable implants and to optimize the therapy with TA for specific intra-articular diseases.

3D screen printing technology enables fabrication of oral drug dosage forms with freely tailorable release profiles

3D printing offers new opportunities to customize oral dosage forms of pharmaceuticals for different patient populations, improving patient safety, care, and compliance. Although several notable 3D print technologies have been developed, such as inkjet printing, powder-based printing, selective laser sintering (SLS) printing, and fused deposition modelling (FDM), among others, their capacity is often limited by the number of printing heads. 3D screen-printing (3DSP) is based on a classic flatbed screen printing that is widely used in industrial applications for technical applications. 3DSP can build up thousands of units per screen simultaneously, enabling mass customization of pharmaceuticals. Here, we use 3DSP to investigate two novel paste formulations: immediate-release (IR) and extended-release (ER) using Paracetamol (acetaminophen) as the active pharmaceutical ingredient (API). Both disk-shaped and donut-shaped tablets were fabricated using one or both pastes to design drug delivery systems (DDS) with tailored API release profiles. The size and mass of the produced tablets demonstrated high uniformity. Characterization of the tablets physical properties, such as breaking force (25-39 N) and friability (0.002-0.237%), adhering to Ph. Eur (10th edition). Finally, drug release tests with a phosphate buffer at pH 5.8 showed Paracetamol release depended on the IR- and ER paste materials and their respective compartment size of the composite DDS, which can be readily varied using 3DSP. This work further demonstrates the potential of 3DSP to manufacture complex oral dosage forms exhibiting custom release functionalities for mass production.

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.

Study and Characterization of Polyvinyl Alcohol-Based Formulations for 3D Printlets Obtained via Fused Deposition Modeling

Three-dimensional (3D) printing has emerged as a new promising technique for the production of personalized dosage forms and medical devices. Polyvinyl alcohol is prominently used as a source material to produce 3D-printed medicines via fused deposition modeling (FDM)-a technology that combines hot melt extrusion and 3D printing. A preliminary screening of three grades of PVA indicated that partially hydrolyzed PVA with a molecular weight (MW) of 31,000-50,000 and plasticized with sorbitol was most suitable for 3D printing. Paracetamol was used as a model drug. The materials and the produced filaments were characterized by X-ray powder diffraction (XRPD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The complex viscosity (η*) of the polymer melts was determined as a function of the angular frequency (ω) at the printing temperature to assess their printability. Three-dimensional printlets with a 40% infill exhibited an immediate release of the API, while tablets with a higher infill were prone to a prolonged release regardless of the filament drug loading. A factorial design was used to give more insight into the influence of the drug-loading of the filaments and the tablet infill as independent variables on the production of 3D printlets. The Pareto chart confirmed that the infill had a statistically significant effect on the dissolution rate after 45 min, which was chosen as the response variable.

Droplet-Based Microfluidics: Applications in Pharmaceuticals

Droplet-based microfluidics offer great opportunities for applications in various fields, such as diagnostics, food sciences, and drug discovery. A droplet provides an isolated environment for performing a single reaction within a microscale-volume sample, allowing for a fast reaction with a high sensitivity, high throughput, and low risk of cross-contamination. Owing to several remarkable features, droplet-based microfluidic techniques have been intensively studied. In this review, we discuss the impact of droplet microfluidics, particularly focusing on drug screening and development. In addition, we surveyed various methods of device fabrication and droplet generation/manipulation. We further highlight some promising studies covering drug synthesis and delivery that were updated within the last 5 years. This review provides researchers with a quick guide that includes the most up-to-date and relevant information on the latest scientific findings on the development of droplet-based microfluidics in the pharmaceutical field.

Formulation and characterization of pressure-assisted microsyringe 3D-printed scaffolds for controlled intravaginal antibiotic release

Bacterial vaginosis (BV) is a highly recurrent vaginal condition linked with many health complications. Topical antibiotic treatments for BV are challenged with drug solubility in vaginal fluid, lack of convenience and user adherence to daily treatment protocols, among other factors. 3D-printed scaffolds can provide sustained antibiotic delivery to the female reproductive tract (FRT). Silicone vehicles have been shown to provide structural stability, flexibility, and biocompatibility, with favorable drug release kinetics. This study formulates and characterizes novel metronidazole-containing 3D-printed silicone scaffolds for eventual application to the FRT. Scaffolds were evaluated for degradation, swelling, compression, and metronidazole release in simulated vaginal fluid (SVF). Scaffolds retained high structural integrity and sustained release. Minimal mass loss (<6%) and swelling (<2%) were observed after 14 days in SVF, relative to initial post-cure measurements. Scaffolds cured for 24 hr (50 °C) demonstrated elastic behavior under 20% compression and 4.0 N load. Scaffolds cured for 4 hr (50 °C), followed by 72 hr (4 °C), demonstrated the highest, sustained, metronidazole release (4.0 and 27.0 µg/mg) after 24 hr and 14 days, respectively. Based upon daily release profiles, it was observed that the 24 hr timepoint had the greatest metronidazole release of 4.08 μg/mg for scaffolds cured at 4 hr at 50 °C followed by 72 hr at 4 °C. For all curing conditions, release of metronidazole after 1 and 7 days showed > 4.0-log reduction in Gardnerella concentration. Negligible cytotoxicity was observed in treated keratinocytes comparable to untreated cells, This study shows that pressure-assisted microsyringe 3D-printed silicone scaffolds may provide a versatile vehicle for sustained metronidazole delivery to the FRT.

Combinatorial 3D printed dosage forms for a two-step and controlled drug release

Fused deposition modeling (FDM) and selective laser sintering (SLS) are two of the most employed additive manufacturing (AM) techniques within the pharmaceutical research field. Despite the numerous advantages of different AM methods, their respective drawbacks have yet to be fully addressed, and therefore combinatorial systems are starting to emerge. In the present study, hybrid systems comprising SLS inserts and a two-compartment FDM shell are developed to achieve controlled release of the model drug theophylline. Via the use of SLS a partial amorphization of the drug is demonstrated, which can be advantageous in the case of poorly soluble drugs, and it is shown that sintering parameters can regulate the dosage and release kinetics of the drug from the inserts. Furthermore, via different combinations of inserts within the FDM-printed shell, various drug release patterns, such as a two-step or prolonged release, can be achieved. The study serves as a proof of concept, highlighting the advantages of combining two AM techniques, both to overcome their respective shortcomings and to develop modular and highly tunable drug delivery devices.

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.

Microbial Polysaccharide-Based Formulation with Silica Nanoparticles; A New Hydrogel Nanocomposite for 3D Printing

Natural polysaccharides are highly attractive biopolymers recommended for medical applications due to their low cytotoxicity and hydrophilicity. Polysaccharides and their derivatives are also suitable for additive manufacturing, a process in which various customized geometries of 3D structures/scaffolds can be achieved. Polysaccharide-based hydrogel materials are widely used in 3D hydrogel printing of tissue substitutes. In this context, our goal was to obtain printable hydrogel nanocomposites by adding silica nanoparticles to a microbial polysaccharide's polymer network. Several amounts of silica nanoparticles were added to the biopolymer, and their effects on the morpho-structural characteristics of the resulting nanocomposite hydrogel inks and subsequent 3D printed constructs were studied. FTIR, TGA, and microscopy analysis were used to investigate the resulting crosslinked structures. Assessment of the swelling characteristics and mechanical stability of the nanocomposite materials in a wet state was also conducted. The salecan-based hydrogels displayed excellent biocompatibility and could be employed for biomedical purposes, according to the results of the MTT, LDH, and Live/Dead tests. The innovative, crosslinked, nanocomposite materials are recommended for use in regenerative medicine.

Additive Manufacturing and Physicomechanical Characteristics of PEGDA Hydrogels: Recent Advances and Perspective for Tissue Engineering

In this brief review, we discuss the recent advancements in using poly(ethylene glycol) diacrylate (PEGDA) hydrogels for tissue engineering applications. PEGDA hydrogels are highly attractive in biomedical and biotechnology fields due to their soft and hydrated properties that can replicate living tissues. These hydrogels can be manipulated using light, heat, and cross-linkers to achieve desirable functionalities. Unlike previous reviews that focused solely on material design and fabrication of bioactive hydrogels and their cell viability and interactions with the extracellular matrix (ECM), we compare the traditional bulk photo-crosslinking method with the latest three-dimensional (3D) printing of PEGDA hydrogels. We present detailed evidence combining the physical, chemical, bulk, and localized mechanical characteristics, including their composition, fabrication methods, experimental conditions, and reported mechanical properties of bulk and 3D printed PEGDA hydrogels. Furthermore, we highlight the current state of biomedical applications of 3D PEGDA hydrogels in tissue engineering and organ-on-chip devices over the last 20 years. Finally, we delve into the current obstacles and future possibilities in the field of engineering 3D layer-by-layer (LbL) PEGDA hydrogels for tissue engineering and organ-on-chip devices.

3D Printing Technology as a Promising Tool to Design Nanomedicine-Based Solid Dosage Forms: Contemporary Research and Future Scope

3D printing technology in medicine is gaining great attention from researchers since the FDA approved the first 3D-printed tablet (Spritam®) on the market. This technique permits the fabrication of various types of dosage forms with different geometries and designs. Its feasibility in the design of different types of pharmaceutical dosage forms is very promising for making quick prototypes because it is flexible and does not require expensive equipment or molds. However, the development of multi-functional drug delivery systems, specifically as solid dosage forms loaded with nanopharmaceuticals, has received attention in recent years, although it is challenging for formulators to convert them into a successful solid dosage form. The combination of nanotechnology with the 3D printing technique in the field of medicine has provided a platform to overcome the challenges associated with the fabrication of nanomedicine-based solid dosage forms. Therefore, the major focus of the present manuscript is to review the recent research developments that involved the formulation design of nanomedicine-based solid dosage forms utilizing 3D printing technology. Utilization of 3D printing techniques in the field of nanopharmaceuticals achieved the successful transformation of liquid polymeric nanocapsules and liquid self-nanoemulsifying drug delivery systems (SNEDDS) to solid dosage forms such as tablets and suppositories easily with customized doses as per the needs of the individual patient (personalized medicine). Furthermore, the present review also highlights the utility of extrusion-based 3D printing techniques (Pressure-Assisted Microsyringe-PAM; Fused Deposition Modeling-FDM) to produce tablets and suppositories containing polymeric nanocapsule systems and SNEDDS for oral and rectal administration. The manuscript critically analyzes contemporary research related to the impact of various process parameters on the performance of 3D-printed solid dosage forms.

Soft robot-enabled controlled release of oral drug formulations

The creation of highly effective oral drug delivery systems (ODDSs) has long been the main objective of pharmaceutical research. Multidisciplinary efforts involving materials, electronics, control, and pharmaceutical sciences encourage the development of robot-enabled ODDSs. Compared with conventional rigid robots, soft robots potentially offer better mechanical compliance and biocompatibility with biological tissues, more versatile shape control and maneuverability, and multifunctionality. In this paper, we first describe and highlight the importance of manipulating drug release kinetics, i.e. pharmaceutical kinetics. We then introduce an overview of state-of-the-art soft robot-based ODDSs comprising resident, shape-programming, locomotive, and integrated soft robots. Finally, the challenges and outlook regarding future soft robot-based ODDS development are discussed.

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.

Controlled Release of Felodipine from 3D-Printed Tablets with Constant Surface Area: Influence of Surface Geometry

In this study, 3D-printed tablets with a constant surface area were designed and fabricated using polylactic acid (PLA) in the outer compartment and polyvinyl alcohol and felodipine (FDP) in the inner compartment. The influences of different surface geometries of the inner compartment, namely, round, hexagon, square, and triangle, on drug release from 3D-printed tablets were also studied. The morphology and porosity of the inner compartment were determined using scanning electron microscopy and synchrotron radiation X-ray tomographic microscopy, respectively. Additionally, drug content and drug release were also evaluated. The results revealed that the round-shaped geometry seemed to have the greatest total surface area of the inner compartment, followed by square-shaped, hexagon-shaped, and triangle-shaped geometries. FDP-loaded 3D-printed tablets with triangle and hexagon surface geometries had the slowest drug release (about 80% within 24 h). In the round-shaped and square-shaped 3D-printed tablets, complete drug release was observed within 12 h. Furthermore, the drug release from triangle-shaped 3D-printed tablets with double the volume of the inner compartment was faster than that of a smaller volume. This was due to the fact that a larger tablet volume increased the surface area contacting the medium, resulting in a faster drug release. The findings indicated that the surface geometry of 3D-printed tablets with a constant surface area affected drug release. This study suggests that 3D printing technology may be used to develop oral solid dosage forms suitable for customized therapeutic treatments.