Integration of 3D printing with dosage forms: A new perspective for modern healthcare

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.

3D printing chronicles in medical devices and pharmaceuticals: tracing the evolution and historical milestones

The objective of this study is to collect the significant advancements of 3D printed medical devices in the biomedical area in recent years. Especially related to a range of diseases and the polymers employed in drug administration. To address the existing limitations and constraints associated with the method used for producing 3D printed medical devices, in order to optimize their suitability for degradation. The compilation and use of research papers, reports, and patents that are relevant to the key keywords are employed to improve comprehension. According to this thorough investigation, it can be inferred that the 3D Printing method, specifically Fuse Deposition Modeling (FDM), is the most suitable and convenient approach for preparing medical devices. This study provides an analysis and summary of the development trend of 3D printed implantable medical devices, focusing on the production process, materials specially the polymers, and typical items associated with 3D printing technology. This study offers a comprehensive examination of nanocarrier research and its corresponding discoveries. The FDM method, which is already facing significant challenges in terms of achieving optimal performance and cost reduction, will experience remarkable advantages from this highly valuable technology. The objective of this analysis is to showcase the efficacy and limitations of 3D-printing applications in medical devices through thorough research, highlighting the significant technological advancements it offers. This article provides a comprehensive overview of the most recent research and discoveries on 3D-printed medical devices, offering significant insights into their study.

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.

Core Legal Challenges for Medical 3D Printing in the EU

3D printing has been adopted into routine use for certain medical applications, but more widespread usage has been hindered by, among other things, unclear legislation. We performed an analysis, using legal doctrinal study and legal informatics, of relevant EU legislation and case law in four issues relevant to medical 3D printing (excluding bioprinting or pharmacoprinting): pre-market approval, post-market liability, intellectual property rights, and data protection. Several gaps and uncertainties in the current legislation and interpretations were identified. In particular, we regard the current EU regulatory framework to be quite limiting and inflexible, exemplifying a cautionary approach common in EU law. Though the need to establish high safety standards in order to protect patients as a disadvantaged population is understood, both legal uncertainties and overregulation are seen as harmful to innovation. Hence, more adaptive legislation is called for to ensure continuous innovation efforts and enhanced patient outcomes.

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.

Facile fabrication of an extended-release tablet of Ticagrelor using three dimensional printing technology

The objective of the study was to fabricate tailored extended-release tablets of blood thinner Ticagrelor as once-daily dosing using additive manufacturing for better compliance in heart failure therapy. The solid work design of the tablet was printed using hot melt extrusion (HME) based 3D printing by optimized mixture of Eudragit RS-100, plasticizer and drug for producing extrudable and printable filaments. FTIR and TGA results showed no covalent interaction among ingredients and no decomposition during HME process, respectively. Friability, weight variation, assay and content uniformity tests met USP requirements, while the mean hardness of the tablets was calculated in a value between 40 and 50 kg. According to DSC and XRD results, the crystallinity state of the Ticagrelor was converted to an amorphous one in the tablet matrix. Smooth surfaces with multiple deposited layers were observed using SEM. In comparison, the maximum Ticagrelor release of 100% after 120 min from Brilinta® tablets was decreased to 97% in 400 min from the 3D tablet at infill of 90%. Korsmeyer-Peppas kinetic model showed the drug release mechanism is affected by diffusion and swelling. In general, fabrication of the extended-release 3D printed tablet of Ticagrelor using HME-based-additive manufacturing has the potential to provide specific doses with tailored kinetic release for personalized medicine, improving adherence at point-of-care.

Exploiting Pharma 4.0 Technologies in the Non-Biological Complex Drugs Manufacturing: Innovations and Implications

The pharmaceutical industry has entered an era of transformation with the emergence of Pharma 4.0, which leverages cutting-edge technologies in manufacturing processes. These hold tremendous potential for enhancing the overall efficiency, safety, and quality of non-biological complex drugs (NBCDs), a category of pharmaceutical products that pose unique challenges due to their intricate composition and complex manufacturing requirements. This review attempts to provide insight into the application of select Pharma 4.0 technologies, namely machine learning, in silico modeling, and 3D printing, in the manufacturing process of NBCDs. Specifically, it reviews the impact of these tools on NBCDs such as liposomes, polymeric micelles, glatiramer acetate, iron carbohydrate complexes, and nanocrystals. It also addresses regulatory challenges associated with the implementation of these technologies and presents potential future perspectives, highlighting the incorporation of digital twins in this field of research as it seems to be a very promising approach, namely for the optimization of NBCDs manufacturing processes.

3D-to-4D Structures: an Exploration in Biomedical Applications

3D printing is a cutting-edge technique for manufacturing pharmaceutical drugs (Spritam), polypills (guaifenesin), nanosuspension (folic acid), and hydrogels (ibuprofen) with limitations like the choice of materials, restricted size of manufacturing, and design errors at lower and higher dimensions. In contrast, 4D printing represents an advancement on 3D printing, incorporating active materials like shape memory polymers and liquid crystal elastomers enabling printed objects to change shape in response to stimuli. 4D printing offers numerous benefits, including greater printing capacity, higher manufacturing efficiency, improved quality, lower production costs, reduced carbon footprint, and the ability to produce a wider range of products with greater potential. Recent examples of 4D printing advancements in the clinical setting include the development of artificial intravesicular implants for bladder disorders, 4D-printed hearts for transplant, splints for tracheobronchomalacia, microneedles for tissue wound healing, hydrogel capsules for ulcers, and theragrippers for anticancer drug delivery. This review highlights the advantages of 4D printing over 3D printing, recent applications in manufacturing smart pharmaceutical drug delivery systems with localized action, lower incidence of drug administration, and better patient compliance. It is recommended to conduct substantial research to further investigate the development and applicability of 4D printing in the future.

Three-Dimensional Printing Model Enhances Correct Identification and Understanding of Pelvic Fracture in Medical Students

OBJECTIVE

Understanding the anatomy behind a pelvic fracture can be a significant challenge to medical students. Recent advances in three-dimensional printing technology offers a novel approach to facilitate the learning of complex fracture. We have described here how the 3-dimension printing (3Dp) models can help medical students improve their understanding in and identification of pelvic fractures.

DESIGN

One hundred students were randomized into 2 teaching module groups (with or without 3Dp models). Prior to randomization assignment, a 50-minute didactic lecture covering elementary knowledge of anatomy, Young-Burgess classification, and traumatic mechanism of pelvic fracture was delivered to all students. The 3Dp group received X-rays, CT images, and 3Dp models of the eight pelvic fractures during presentation, while the students in the control group only obtained X-rays and CT scans of the same 8 pelvic fractures. Young-Burgess classification system and injury mechanism of pelvic fracture, time for evaluation, and subjective questions were conducted to assess the learning outcomes.

SETTING

A medical student program based in a LevelⅠtrauma center PARTICIPANTS: One hundred students in their 4th year of a 5-year clinical medicine program (for a medical bachelor degree) RESULTS: Students receiving 3Dp model had a higher rate of identifying the correct pelvic fracture via Young-Burgess identification compared to these without 3Dp model. Moreover, the accuracy of identifying the injury mechanism was significantly higher in the 3Dp group than that in group without 3Dp model. Participant in 3Dp group had faster assessment time compared to the control group. Subjective survey results suggested that 3Dp model would increase the learning interest and enhance the understanding of pelvic fracture. In addition, majority of students (83%) reported that they would like to use 3Dp model in other surgical course education.

CONCLUSIONS

3Dp model increased the perceived accuracy of pelvic fracture identification and understanding of injury mechanism. Moreover, 3Dp model promoted the subjective interest and motivation of students in pelvic fracture learning. Therefore, 3Dp model can be considered as a valuable educational tool for learning pelvic fracture in medical students.

New Frontiers in Three-Dimensional Culture Platforms to Improve Diabetes Research

Diabetes mellitus is associated with defects in islet β-cell functioning and consequent hyperglycemia resulting in multi-organ damage. Physiologically relevant models that mimic human diabetic progression are urgently needed to identify new drug targets. Three-dimensional (3D) cell-culture systems are gaining a considerable interest in diabetic disease modelling and are being utilized as platforms for diabetic drug discovery and pancreatic tissue engineering. Three-dimensional models offer a marked advantage in obtaining physiologically relevant information and improve drug selectivity over conventional 2D (two-dimensional) cultures and rodent models. Indeed, recent evidence persuasively supports the adoption of appropriate 3D cell technology in β-cell cultivation. This review article provides a considerably updated view of the benefits of employing 3D models in the experimental workflow compared to conventional animal and 2D models. We compile the latest innovations in this field and discuss the various strategies used to generate 3D culture models in diabetic research. We also critically review the advantages and the limitations of each 3D technology, with particular attention to the maintenance of β-cell morphology, functionality, and intercellular crosstalk. Furthermore, we emphasize the scope of improvement needed in the 3D culture systems employed in diabetes research and the promises they hold as excellent research platforms in managing diabetes.

Novel Approach to Pharmaceutical 3D-Printing Omitting the Need for Filament-Investigation of Materials, Process, and Product Characteristics

The utilized 3D printhead employs an innovative hot-melt extrusion (HME) design approach being fed by drug-loaded polymer granules and making filament strands obsolete. Oscillatory rheology is a key tool for understanding the behavior of a polymer melt in extrusion processes. In this study, small amplitude shear oscillatory (SAOS) rheology was applied to investigate formulations of model antihypertensive drug Metoprolol Succinate (MSN) in two carrier polymers for pharmaceutical three-dimensional printing (3DP). For a standardized printing process, the feeding polymers viscosity results were correlated to their printability and a better understanding of the 3DP extrudability of a pharmaceutical formulation was developed. It was found that the printing temperature is of fundamental importance, although it is limited by process parameters and the decomposition of the active pharmaceutical ingredients (API). Material characterization including differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA) of the formulations were performed to evaluate component miscibility and ensure thermal durability. To assure the development of a printing process eligible for approval, all print runs were investigated for uniformity of mass and uniformity of dosage in accordance with the European Pharmacopoeia (Ph. Eur.).

Fabrication of Mucoadhesive Films Containing Pharmaceutical Ionic Liquid and Eudragit Polymer Using Pressure-Assisted Microsyringe-Type 3D Printer for Treating Oral Mucositis

Oral mucositis in the oral cavity, caused by radiation therapy and chemotherapy, requires personalized care and therapy due to variations in the lesions of patients. In the present study, we fabricated a model of personalized oral film containing an ibuprofen/lidocaine ionic liquid (IL) for patients with oral mucositis using a pressure-assisted microsyringe-type 3D printer at room temperature. The film contained a Eudragit polymer (L100, EPO, or RSPO) to make the film solid, and the printer ink was composed of organo ink (organic solvent to dissolve both drugs and the Eudragit polymer). The viscosity of the printer ink was assessed to investigate its extrudability. The contact angle and the surface tension at the interface between each liquid printer ink and a solid polypropylene sheet were measured to determine the retention of the ink in 3D printing. The physical properties of IL-loaded Eudragit-based dry films were examined by X-ray diffraction and differential scanning calorimetry. Dissolution tests indicated that IL-loaded films containing a Eudragit polymer exhibited different drug release rates in phosphate buffer (pH 6.8; Eudragit L100 > IL alone > Eudragit EPO > Eudragit RSPO). These results provide useful information for the specific fabrication of IL-loaded polymer-based films using organo inks and pressure-assisted microsyringe-type 3D printers.

Development of a new 3D bioprinted antibiotic delivery system based on a cross-linked gelatin-alginate hydrogel

3D bioprinting uses bioink deposited directly on a collector to create any previously designed 3D model. One of the most common and the easiest to operate bioinks is gelatin-alginate hydrogel. The present study aimed to combine 3D bioprinting with different cross-linking techniques to develop a new stable and biodegradable gelatin-alginate hydrogel matrix for drug delivery applications. The matrix-building biopolymers were crosslinked by ionotropic gelation with Ca²⁺ ions, chemical crosslinking with GTA or a combination of the two crosslinkers at various concentrations. The influence of the crosslinking method on the hydrogel properties, stability and structure was examined using scanning electron and optical microscopy, differential scanning calorimetry and thermogravimetric analysis. Analyses included tests of hydrogel equilibrium swelling ratio and release of marker substance. Subsequently, biological properties of the matrices loaded with the antibiotic chlorhexidine were studied, including cytotoxicity on HaCAT cells and antibacterial activity on Staphylococcus aureus and Escherichia coli bacteria. The conducted study confirmed that the 3D bioprinted cross-linked drug-loaded alginate-gelatin hydrogel is a good and satisfying material for potential use as a drug delivery system.

Investigation of Patient-Centric 3D-Printed Orodispersible Films Containing Amorphous Aripiprazole

The objective of this study was to design and evaluate an orodispersible film (ODF) composed of aripiprazole (ARP), prepared using a conventional solvent casting technique, and to fuse a three-dimensional (3D) printing technique with a hot-melt extrusion (HME) filament. Klucel® LF (hydroxypropyl cellulose, HPC) and PE-05JPS® (polyvinyl alcohol, PVA) were used as backbone polymers for 3D printing and solvent casting. HPC-, PVA-, and ARP-loaded filaments were applied for 3D printing using HME. The physicochemical and mechanical properties of the 3D printing filaments and films were optimized based on the composition of the polymers and the processing parameters. The crystalline states of drug and drug-loaded formulations were investigated using differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). The dissolution and disintegration of the 3D-printed films were faster than those of solvent-cast films. HPC-3D printed film was fully disintegrated within 45 ± 3.5 s. The dissolution rate of HPC films reached 80% within 30 min at pH 1.2 and pH 4.0 USP buffer. There was a difference in the dissolution rate of about 5 to 10% compared to PVA films at the same sampling time. The root mean square of the roughness (Rq) values of each sample were evaluated using atomic force microscopy. The higher the Rq value, the rougher the surface, and the larger the surface area, the more salivary fluid penetrated the film, resulting in faster drug release and disintegration. Specifically, The HPC 3D-printed film showed the highest Rq value (102.868 nm) and average surface roughness (85.007 nm). The puncture strength of 3D-printed films had desirable strength with HPC (0.65 ± 0.27 N/mm2) and PVA (0.93 ± 0.15 N/mm2) to prevent deformation compared to those of marketed film products (over 0.34 N/mm2). In conclusion, combining polymer selection and 3D printing technology could innovatively design ODFs composed of ARP to solve the unmet medical needs of psychiatric patients.

A Design Approach to Optimise Secure Remote Three-Dimensional (3D) Printing: A Proof-of-Concept Study towards Advancement in Telemedicine

Telemedicine is defined as the delivery of healthcare services at a distance using electronic means. The incorporation of 3D printing in the telemedicine cycle could result in pharmacists designing and manufacturing personalised medicines based on the electronic prescription received. Even with the advantages of telemedicine, numerous barriers to the uptake hinder the wider uptake. Of particular concern is the cyber risk associated with the remote digital transfer of the computer-aided design (CAD) file (acting as the electronic prescription) to the 3D printer and the reproducibility of the resultant printed medicinal products. This proof-of-concept study aimed to explore the application of secure remote 3D printing of model solid dosage forms using the patented technology, DEFEND3D, which is designed to enhance cybersecurity and intellectual property (IP) protection. The size, shape, and colour of the remote 3D-printed model medicinal products were also evaluated to ensure the end-product quality was user-focused. Thermoplastic polyurethane (TPU) and poly(lactic) acid (PLA) were chosen as model polymers due to their flexibility in preventing breakage printing and ease of printing with fused deposition modelling (FDM). Our work confirmed the potential of secure remote 3D (FDM) printing of prototype solid dosage forms resulting in products with good reproducibility, resolution, and quality towards advancements in telemedicine and digital pharmacies. The limitation of the work presented here was the use of model polymers and not pharmaceutically relevant polymers. Further work could be conducted using the same designs chosen in this study with pharmaceutically relevant polymers used in hot-melt extrusion (HME) with shown suitability for FDM 3D printing. However, it should be noted that any challenges that may occur with pharmaceutically relevant polymers are likely to be related to the polymer's printability and printer choice as opposed to the ability of the CAD file to be transferred to the printer remotely.

Introducing Fiber-Assisted Colorimetric Measurements as a Quality Control Tool of Hot Melt Extruded Filaments

Pharmaceutical and medicinal printing technologies allow personalization and on-demand manufacturing of drug and medicinal products. Being able to manufacture patient tailored dosage forms or medical devices in a pharmacy, medical office, dental laboratory, or hospital at the point of care raises new demands on quality control procedures. For Fused Deposition Modeling, for example, it must be ensured that the starting materials, the (drug-loaded) filaments, are not accidentally exchanged by the operator. This study investigated the potential of colorimetric measurements for direct and indirect determination of the identity of extruded filaments consisting of polymer matrix, different API and/or coloring agents. Since reflection measurements were affected by surface properties of the filaments, a self-constructed filament holder was utilized with an optical fiber positioned in a 180° angle to a white light LED to perform transmission measurements. It was possible to distinguish filaments with different API concentrations by their color values, taking into account that transmission partially decreased by increased API concentration. Therefore, the intensity of the light source had to be adjusted depending on the transparency of the filament. It was shown that colorimetry can be used as a quality control tool to detect differences in drug-loading and is able to distinguish various extruded batches. Additionally, if differences in API/polymer concentrations do not lead to significant changes in L*a*b values, coloring agents were used as additives in low concentrations to color code filaments. In future studies, the setup must be supplemented with a standardized light source and obscuring filters for light intensity adjustments.

The Development of Innovative Dosage Forms of the Fixed-Dose Combination of Active Pharmaceutical Ingredients

The development of innovative forms of combination drugs is closely related to the invention of the multilayer tablet press, polymers for pharmaceutical applications, the hot-melt extrusion process, and 3D printing in the pharmaceutical industry. However, combining multiple drugs within the same dosage form can bring many physicochemical and pharmacodynamic interactions. More and more new forms of fixed-dose combinations (FDCs) have been developed due to work to overcome the incompatibility of active substances or to obtain different drug release profiles in the same dosage form. This review provides discussions of the application of various innovation formulation technologies of FDC drugs such as bilayer system, multilayer tablet, active film coating, hot-melt extrusion, and 3D printing, taking into account the characteristics of the key ingredients in the FDC formulation and presenting technological problems and challenges related to the development of combination drugs. Moreover, the article summarizes the range of dosage forms that have been made using these technologies over the past 30 years.

Lyophilized ophthalmologic patches as novel corneal drug formulations using a semi-solid extrusion 3D printer

3D printing technology is a novel and practical approach for producing unique and complex industrial and medical objects. In the pharmaceutical field, the approval of 3D printed tablets by the US Food and Drug Administration has led to other 3D printed drug formulations and dosage forms being proposed and investigated. Here, we report novel ophthalmologic patches for controlled drug release fabricated using a semi-solid material extrusion-type 3D printer. The patch-shaped objects were 3D printed using hydrogel-based printer inks composed of hypromellose (HPMC), sugar alcohols (mannitol, xylitol), and drugs, then freeze-dried. The viscous properties of the printer inks and patches were dependent on the HPMC and sugar alcohol concentrations. Then, the physical properties, surface structure, water uptake, antimicrobial activity, and drug release profile of lyophilized patches were characterized. Lyophilized ophthalmologic patches with different dosages and patterns were fabricated as models of personalized treatments prepared in hospitals. Then, ophthalmologic patches containing multiple drugs were fabricated using commercially available eye drop formulations. The current study indicates that 3D printing is applicable to producing novel dosage forms because its high flexibility allows the preparation of patient-tailored dosages in a clinical setting.

Polysaccharide 3D Printing for Drug Delivery Applications

3D printing, or additive manufacturing, has gained considerable interest due to its versatility regarding design as well as in the large choice of materials. It is a powerful tool in the field of personalized pharmaceutical treatment, particularly crucial for pediatric and geriatric patients. Polysaccharides are abundant and inexpensive natural polymers, that are already widely used in the food industry and as excipients in pharmaceutical and cosmetic formulations. Due to their intrinsic properties, such as biocompatibility, biodegradability, non-immunogenicity, etc., polysaccharides are largely investigated as matrices for drug delivery. Although an increasing number of interesting reviews on additive manufacturing and drug delivery are being published, there is a gap concerning the printing of polysaccharides. In this article, we will review recent advances in the 3D printing of polysaccharides focused on drug delivery applications. Among the large family of polysaccharides, the present review will particularly focus on cellulose and cellulose derivatives, chitosan and sodium alginate, printed by fused deposition modeling and extrusion-based printing.

3D Printed Personalized Medicine for Cancer: Applications for Betterment of Diagnosis, Prognosis and Treatment

Cancer treatment is challenging due to the tumour heterogeneity that makes personalized medicine a suitable technique for providing better cancer treatment. Personalized medicine analyses patient-related factors like genetic make-up and lifestyle and designs treatments that offer the benefits of reduced side effects and efficient drug delivery. Personalized medicine aims to provide a holistic way for prevention, diagnosis and treatment. The customization desired in personalized medicine is produced accurately by 3D printing which is an established technique known for its precision. Different 3D printing techniques exhibit their capability in producing cancer-specific medications for breast, liver, thyroid and kidney tumours. Three-dimensional printing displays major influence on cancer modelling and studies using cancer models in treatment and diagnosis. Three-dimensional printed personalized tumour models like physical 3D models, bioprinted models and tumour-on-chip models demonstrate better in vitro and in vivo correlation in drug screening, cancer metastasis and prognosis studies. Three-dimensional printing helps in cancer modelling; moreover, it has also changed the facet of cancer treatment. Improved treatment via custom-made 3D printed devices, implants and dosage forms ensures the delivery of anticancer agents efficiently. This review covers recent applications of 3D printed personalized medicine in various cancer types and comments on the possible future directions like application of 4D printing and regularization of 3D printed personalized medicine in healthcare.

New Insights into the Application of 3D-Printing Technology in Hernia Repair

Abdominal hernia repair using prosthetic materials is among the surgical interventions most widely performed worldwide. These materials, or meshes, are implanted to close the hernial defect, reinforcing the abdominal muscles and reestablishing mechanical functionality of the wall. Meshes for hernia repair are made of synthetic or biological materials exhibiting multiple shapes and configurations. Despite the myriad of devices currently marketed, the search for the ideal mesh continues as, thus far, no device offers optimal tissue repair and restored mechanical performance while minimizing postoperative complications. Additive manufacturing, or 3D-printing, has great potential for biomedical applications. Over the years, different biomaterials with advanced features have been successfully manufactured via 3D-printing for the repair of hard and soft tissues. This technological improvement is of high clinical relevance and paves the way to produce next-generation devices tailored to suit each individual patient. This review focuses on the state of the art and applications of 3D-printing technology for the manufacture of synthetic meshes. We highlight the latest approaches aimed at developing improved bioactive materials (e.g., optimizing antibacterial performance, drug release, or device opacity for contrast imaging). Challenges, limitations, and future perspectives are discussed, offering a comprehensive scenario for the applicability of 3D-printing in hernia repair.

Stereolithography 3D printing technology in pharmaceuticals: a review

Three-dimensional printing (3DP) technology is an innovative tool used in manufacturing medical devices, producing alloys, replacing biological tissues, producing customized dosage forms and so on. Stereolithography (SLA), a 3D printing technique, is very rapid and highly accurate and produces finished products of uniform quality. 3D formulations have been optimized with a perfect tool of artificial intelligence learning techniques. Complex designs/shapes can be fabricated through SLA using the photopolymerization principle. Different 3DP technologies are introduced and the most promising of these, SLA, and its commercial applications, are focused on. The high speed and effectiveness of SLA are highlighted. The working principle of SLA, the materials used and applications of the technique in a wide range of different sectors are highlighted in this review. An innovative idea of 3D printing customized pharmaceutical dosage forms is also presented. SLA compromises several advantages over other methods, such as cost effectiveness, controlled integrity of materials and greater speed. The development of SLA has allowed the development of printed pharmaceutical devices. Considering the present trends, it is expected that SLA will be used along with conventional methods of manufacturing of 3D model. This 3D printing technology may be utilized as a novel tool for delivering drugs on demand. This review will be useful for researchers working on 3D printing technologies.

An updated review on application of 3D printing in fabricating pharmaceutical dosage forms

The concept of "one size fits all" followed by the conventional healthcare system has drawbacks in providing precise pharmacotherapy due to variation in the pharmacokinetics of different patients leading to serious consequences such as side effects. In this regard, digital-based three-dimensional printing (3DP), which refers to fabricating 3D printed pharmaceutical dosage forms with variable geometry in a layer-by-layer fashion, has become one of the most powerful and innovative tools in fabricating "personalized medicine" to cater to the need of therapeutic benefits for patients to the maximum extent. This is achieved due to the tremendous potential of 3DP in tailoring various drug delivery systems (DDS) in terms of size, shape, drug loading, and drug release. In addition, 3DP has a huge impact on special populations including pediatrics, geriatrics, and pregnant women with unique or frequently changing medical needs. The areas covered in the present article are as follows: (i) the difference between traditional and 3DP manufacturing tool, (ii) the basic processing steps involved in 3DP, (iii) common 3DP methods with their pros and cons, (iv) various DDS fabricated by 3DP till date with discussing few research studies in each class of DDS, (v) the drug loading principles into 3D printed dosage forms, and (vi) regulatory compliance.

Diving into 3D (bio)printing: A revolutionary tool to customize the production of drug and cell-based systems for skin delivery

The incorporation of 3D printing technologies in the pharmaceutical industry can revolutionize its R&D, by providing a simple and rapid method to produce tailored one-off batches, each with customized dosages, different compounds, shapes, sizes, and adjusted release rates. Particularly, this type of technology can be advantageous for the development of topical and transdermal drug delivery systems, including patches and microneedles. The use of both systems as drug carriers offers advantages over the oral administration, but the possibility of skin irritation and sensitization, and the high production costs, may hinder the expansion of this market. In this context, 3D printing, a high-resolution technique, allows the design of high quality, personalized, complex and sophisticated structures, thus reducing the production costs and improving the patient compliance. This review covers the 3D printing concept and discusses the relevance of this technology to the pharmaceutical industry, with a special focus on the development of topical and transdermal products - patches and microneedles. The potential of 3D bioprinting for skin applications is also presented, highlighting the development of patch-like skin constructs for wound and burn treatment, and skin equivalents for in vitro research and drug development. Several recent studies were selected to support the relevance of the subjects addressed herein. Additionally, the limitations of these printing technologies are discussed, including regulatory, quality and safety issues.

Practicality of 3D Printed Personalized Medicines in Therapeutics

Technological advances in science over the past century have paved the way for remedial treatment outcomes in various diseases. Pharmacogenomic predispositions, the emergence of multidrug resistance, medication and formulation errors contribute significantly to patient mortality. The concept of "personalized" or "precision" medicines provides a window to addressing these issues and hence reducing mortality. The emergence of three-dimensional printing of medicines over the past decades has generated interests in therapeutics and dispensing, whereby the provisions of personalized medicines can be built within the framework of producing medicines at dispensaries or pharmacies. This plan is a good replacement of the fit-for-all modality in conventional therapeutics, where clinicians are constrained to prescribe pre-formulated dose units available on the market. However, three-dimension printing of personalized medicines faces several hurdles, but these are not insurmountable. In this review, we explore the relevance of personalized medicines in therapeutics and how three-dimensional printing makes a good fit in current gaps within conventional therapeutics in order to secure an effective implementation of personalized medicines. We also explore the deployment of three-dimensional printing of personalized medicines based on practical, legal and regulatory provisions.

Production of Reproducible Filament Batches for the Fabrication of 3D Printed Oral Forms

Patients need medications at a dosage suited to their physiological characteristics. Three-dimensional printing (3DP) technology by fused-filament fabrication (FFF) is a solution for manufacturing medication on demand. The aim of this work was to identify important parameters for the production of reproducible filament batches used by 3DP for oral formulations. Amiodarone hydrochloride, an antiarrhythmic and insoluble drug, was chosen as a model drug because of dosage adaptation need in children. Polyethylene oxide (PEO) filaments containing amiodarone hydrochloride were produced by hot-melt extrusion (HME). Different formulation storage conditions were investigated. For all formulations, the physical form of the drug following HME and fused-deposition modeling (FDM) 3D-printing processes were assessed using thermal analysis and X-ray powder diffraction (XRPD). Filament mechanical properties, linear mass density and surface roughness, were investigated by, respectively, 3-point bending, weighing, and scanning electron microscopy (SEM). Analysis results showed that the formulation storage condition before HME-modified filament linear mass density and, therefore, the oral forms masses from a batch to another. To obtain constant filament apparent density, it has been shown that a constant and reproducible drying condition is required to produce oral forms with constant mass.

Solvent-free temperature-facilitated direct extrusion 3D printing for pharmaceuticals

In an era moving towards digital health, 3D printing has successfully proven its applicability in providing personalised medicine through a technology-based approach. Among the different 3D printing techniques, direct extrusion 3D printing has been demonstrated as a promising approach for on demand manufacturing of solid dosage forms. However, it usually requires the use of elevated temperatures and/or the incorporation of an evaporable solvent (usually water). This can implicate the addition of a drying step, which may compromise the integrity of moisture- or temperature-sensitive drugs, and open the door for additional quality control challenges. Here, we demonstrate a new approach that simplifies direct extrusion 3D printing process with the elimination of the post-printing drying step, by merely adding a fatty glyceride, glyceryl monostearate (GMS), to a model drug (theophylline) and permeable water insoluble methacrylate polymers (Eudragit RL and RS). Indeed, rheological studies indicated that the addition of a combination of a plasticiser, (triethyl citrate), and GMS to theophylline: methacrylate polymer blends significantly reduced the extensional viscosity (to <2.5 kPa·Sec) at 90 °C. Interestingly, GMS demonstrated a dual temperature-dependant behaviour by acting both as a plasticiser and a lubricant at printing temperature (90-110 °C), while aiding solidification at room temperature. X-ray powder diffraction indicated incomplete miscibility of GMS within the polymeric matrix at room temperature with the presence of a subtle diffraction peak, at 2(Θ) = 20°. The 3D printed tablets showed acceptable compendial weight and content uniformity as well as sufficient mechanical resistance. In vitro theophylline release from 3D printed tablets was dependant on Eudragit RL:RS ratio. All in all, this work contributes to the efforts of developing a simplified, facile and low-cost 3D printing for small batch manufacturing of bespoke tablets that circumvents the use of high temperature and post-manufacturing drying step.

3D Printed Bioconstructs: Regenerative Modulation for Genetic Expression

Layer-by-layer deposition of cells, tissues and similar molecules provided by additive manufacturing techniques such as 3D bioprinting offers safe, biocompatible, effective and inert methods for the production of biological structures and biomimetic scaffolds. 3D bioprinting assisted through computer programmes and software develops mutli-modal nano- or micro-particulate systems such as biosensors, dosage forms or delivery systems and other biological scaffolds like pharmaceutical implants, prosthetics, etc. This review article focuses on the implementation of 3D bioprinting techniques in the gene expression, in gene editing or therapy and in delivery of genes. The applications of 3D printing are extensive and include gene therapy, modulation and expression in cancers, tissue engineering, osteogenesis, skin and vascular regeneration. Inclusion of nanotechnology with genomic bioprinting parameters such as gene conjugated or gene encapsulated 3D printed nanostructures may offer new avenues in the future for efficient and controlled treatment and help in overcoming the limitations faced in conventional methods. Moreover, expansion of the benefits from such techniques is advantageous in real-time delivery or in-situ production of nucleic acids into the host cells.

Rekkas D, Vlachou M. 3D-Printed Modified-Release Tablets: A Review of the Recent Advances

The broad spectrum of applications of three-dimensional printing (3D printing, 3DP) has attracted the attention of researchers working in diverse fields. In pharmaceutics, the main idea behind 3D printing products is to design and develop delivery systems that are suited to an individual’s needs. In this way, the size, appearance, shape, and rate of delivery of a wide array of medicines could be easily adjusted. The aim of this chapter is to provide a compilation of the 3D printing techniques, used for the fabrication of oral drug delivery systems, and review the relevant scientific developments in particular those with modified-release characteristics.

Hot Melt Extrusion and its Application in 3D Printing of Pharmaceuticals

Hot Melt Extrusion (HME) is a continuous pharmaceutical manufacturing process that has been extensively investigated for solubility improvement and taste masking of active pharmaceutical ingredients. Recently, it is being explored for its application in 3D printing. 3D printing of pharmaceuticals allows flexibility of dosage form design, customization of dosage form for personalized therapy and the possibility of complex designs with the inclusion of multiple actives in a single unit dosage form. Fused Deposition Modeling (FDM) is a 3D printing technique with a variety of applications in pharmaceutical dosage form development. FDM process requires a polymer filament as the starting material that can be obtained by hot melt extrusion. Recent reports suggest enormous applications of a combination of hot melt extrusion and FDM technology in 3D printing of pharmaceuticals and need to be investigated further. This review in detail describes the HME process, along with its application in 3D printing. The review also summarizes the published reports on the application of HME coupled with 3D printing technology in drug delivery.

Fused Deposition Modeling (FDM), the new asset for the production of tailored medicines

Over the last few years, conventional medicine has been increasingly moving towards precision medicine. Today, the production of oral pharmaceutical forms tailored to patients is not achievable by traditional industrial means. A promising solution to customize oral drug delivery has been found in the utilization of 3D Printing and in particular Fused Deposition Modeling (FDM). Thus, the aim of this systematic literature review is to provide a synthesis on the production of pharmaceutical solid oral forms using FDM technology. In total, 72 relevant articles have been identified via two well-known scientific databases (PubMed and ScienceDirect). Overall, three different FDM methods have been reported: "Impregnation-FDM", "Hot Melt Extrusion coupled with FDM" and "Print-fill", which yielded to the formulation of thermoplastic polymers used as main component, five families of other excipients playing different functional roles and 47 active ingredients. Solutions are underway to overcome the high printing temperatures, which was the initial brake on to use thermosensitive ingredients with this technology. Also, the moisture sensitivity shown by a large number of prints in preliminary storage studies is highlighted. FDM seems to be especially fitted for the treatment of rare diseases, and particular populations requiring tailored doses or release kinetics. For future use of FDM in clinical trials, an implication of health regulatory agencies would be necessary. Hence, further efforts would likely be oriented to the use of a quality approach such as "Quality by Design" which could facilitate its approval by the authorities, and also be an aid to the development of this technology for manufacturers.

3D Printing of Solid Oral Dosage Forms: Numerous Challenges With Unique Opportunities

Since the FDA approval of Spritam, there has been a growing interest in the application of 3D printing in pharmaceutical science. 3D printing is a method of manufacturing involving the layer-by-layer deposition of materials to create a final product according to a digital model. There are various techniques used to achieve this method of printing including the SLS, SLA, FDM, SSE and PB-inkjet printing. In biomanufacturing, bone and tissue engineering involving 3D printing to create scaffolds, while in pharmaceutics, 3D printing was applied in drug development, and the fabrication of drug delivery devices. This paper aims to review the use of some 3D printing techniques in the fabrication of oral solid dosage forms. FDM, SLA SLS, and PB-Inkjet printing processes were found suitable for the fabrication of oral solid dosage forms, though a great deal of the available research was focused on fused deposition modelling due to its availability and flexibility. Process parameters as well as strategies to control the characteristics of printed dosage forms are analysed and discussed. The review also presents the advantages and possible limitations of 3D printing of medicines.

Development of 3D-Printed Layered PLGA Films for Drug Delivery and Evaluation of Drug Release Behaviors

3D printing has been widely used to rapidly manufacture a variety of solid dosage forms on-demand, without sacrificing precision. This study used extrusion-based 3D printing to prepare single-layered, tri-layered, and core-in-shell poly(lactic-co-glycolic acid) (PLGA) films carrying paclitaxel and rapamycin in combination or lidocaine alone. Each layer was composed of either low molecular weight (MW) PLGA or high MW PLGA. In vitro drug release kinetics of paclitaxel, rapamycin, and lidocaine for PLGA films were assessed and compared with PLGA-polyethylene glycol (PEG)-PLGA hydrogel discs. Regardless of the structure of PLGA film, paclitaxel (half-time: 54-63 days) was released faster than when compared with rapamycin (half-time: 74-80 days). In contrast, single-layered PLGA-PEG-PLGA discs released rapamycin (half-time 5.7 h) at a more rapid rate than paclitaxel (half-time: 7.3 h). Single-layered PLGA-PEG-PLGA discs enabled a faster drug release than PLGA films, noting that the disc matrices dissolve in water in 24 h. Similarly, lidocaine incorporated in PLGA films (half-time: 13-36 days) exhibited slower release patterns than that in PLGA-PEG-PLGA discs (half-time: 2.6 h). In vitro drug release patterns were explained using molecular models that simulate drug-polymer interactions. Analysis of models suggested that drug-polymer interactions, location of each drug in the polymeric matrix, and solubility of drugs in water were major factors that determine drug release behaviors from the polymeric films and discs.

Three-dimensional printing in the fight against novel virus COVID-19: Technology helping society during an infectious disease pandemic

Indeed, the scientific milestones set by the ever-emerging three-dimensional printing (3DP) technologies are tremendous. Till now, the innovative 3DP technologies have benefitted the aerospace, automobile, textile, pharmaceutical, and biomedical sectors by developing pre-requisite designed and customized performance standards of the end-user products. As the scientific world, at this moment, is expediting efforts to fight against the highly damaging novel coronavirus (COVID-19) pandemic, the 3DP technologies are facilitating creative solutions in terms of personal protective equipment (PPE), medical equipment (such as ventilators and other respiratory devices), and other health and welfare tools to aid the personal hygiene as well as safe environment for humans by restricting the communication of risks. Various sources (including journal articles, news articles, white papers of the government and other non-profit organizations, commercial enterprises, as well as academic institutions have been reviewed for the collection of the information relevant to COVID-19 and 3DP. This communication presents the recent applications of the 3DP technologies aiding in developing innovative products designed to save the lives of millions of people around the world. Moreover, the potential of 3DP technologies in developing test swabs and controlled medicines has been highlighted. The literature reviewed in the present study indicated that the fused filament fabrication (FFF) is one of the most preferred technologies and contribute about 62% in the overall production of the protective gears developed through overall class of 3DP.

3D Printed Drug Delivery Systems Based on Natural Products

In the last few years, the employment of 3D printing technologies in the manufacture of drug delivery systems has increased, due to the advantages that they offer for personalized medicine. Thus, the possibility of producing sophisticated and tailor-made structures loaded with drugs intended for tissue engineering and optimizing the drug dose is particularly interesting in the case of pediatric and geriatric population. Natural products provide a wide range of advantages for their application as pharmaceutical excipients, as well as in scaffolds purposed for tissue engineering prepared by 3D printing technologies. The ability of biopolymers to form hydrogels is exploited in pressure assisted microsyringe and inkjet techniques, resulting in suitable porous matrices for the printing of living cells, as well as thermolabile drugs. In this review, we analyze the 3D printing technologies employed for the preparation of drug delivery systems based on natural products. Moreover, the 3D printed drug delivery systems containing natural products are described, highlighting the advantages offered by these types of excipients.

Preparation and application of subdivided tablets using 3D printing for precise hospital dispensing

This study aimed to use three-dimensional printing technology to provide patients with accurate, safe and convenient subdivided drugs and bring the transformation of subdivided drugs' fabrication in the hospital. The formulation, preparation process, model and printing parameters, relationship between dose and preset model for printing of spironolactone of 2 mg, 4 mg and hydrochlorothiazide of 5 mg subdivided tablets prepared by three-dimensional printers were investigated in the study. The three-dimensional printed material consists of commercial tablets powders and other excipients, including lactose, corn starch, microcrystalline cellulose, and so on. Mass variation, drug content and drug content uniformity of subdivided tablets obtained by three-dimensional printing were compared with the pharmacists splitting subdivided tablets. Besides, the results from fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray powder diffraction confirmed that the preparation process of spironolactone of 2 mg, 4 mg and hydrochlorothiazide of 5 mg did not change the crystal structure of the active pharmaceutical ingredient. Furthermore, mass variation, drug content range and drug content uniformity of spironolactone of 2 mg, 4 mg and hydrochlorothiazide of 5 mg tablets split by pharmacists failed to comply with European Pharmacopoeia and Chinese Pharmacopoeia, while those of the three-dimensional printed subdivided tablets did. After the review of the ethics committee as a new technology for hospital dispensing, three-dimensional printed spironolactone subdivided tablets of 2 mg have been used in clinical inpatients and was accepted by pharmacists, nurses and patients. Compared with tablets subdivided split by pharmacists, three-dimensional printed spironolactone tablets of 2 mg were more accurate, safer and more customized, which indicated considerable potential in using three-dimensional printing technology as a new method for hospital dispensing.