3D printing for enhanced drug delivery: current state-of-the-art and challenges

Fabrication of mRNA encapsulated lipid nanoparticles using state of the art SMART-MaGIC technology and transfection in vitro

The messenger ribose nucleic acid (mRNA) in the form of Corona virus of 2019 (COVID-19) vaccines were effectively delivered through lipid nanoparticles (LNP) proving its use as effective carriers in clinical applications. In the present work, mRNA (erythropoietin (EPO)) encapsulated LNPs were prepared using a next generation state-of-the-art patented, Sprayed Multi Absorbed-droplet Reposing Technology (SMART) coupled with Multi-channeled and Guided Inner-Controlling printheads (MaGIC) technologies. The LNP-mRNA were synthesized at different N/P ratios and the particles were characterized for particle size and zeta potential (Zetasizer), encapsulation or complexation (gel retardation assay) and transfection (Fluorescence microscopy and ELISA) in MG63 sarcoma cells in vitro. The results showed a narrow distribution of mRNA-lipid particles of 200 nm when fabricated with SMART alone and then the size was reduced to approximately 50 nm with the combination of SMART-MaGIC technologies. The gel retardation assay showed that the N/P > 1 exhibited strong encapsulation of mRNA with lipid. The in vitro results showed the toxicity profile of the lipids where N/P ratio of 5 was optimized with > 50% cell viability. It can be concluded that the functional LNP-mRNA prepared and analyzed with SMART-MaGIC technologies, could be a potential new fabrication method of mRNA loaded LNPs for point-of-service or distributed manufacturing.

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.

3D printing technology and its revolutionary role in stent implementation in cardiovascular disease

Cardiovascular disease (CVD), exemplified by coronary artery disease (CAD), is a global health concern, escalating in prevalence and burden. The etiology of CAD is intricate, involving different risk factors. CVD remains a significant cause of mortality, driving the need for innovative interventions like percutaneous coronary intervention and vascular stents. These stents aim to minimize restenosis, thrombosis, and neointimal hyperplasia while providing mechanical support. Notably, the challenges of achieving ideal stent characteristics persist. An emerging avenue to address this involves enhancing the mechanical performance of polymeric bioresorbable stents using additive manufacturing techniques And Three-dimensional (3D) printing, encompassing various manufacturing technologies, has transcended its initial concept to become a tangible reality in the medical field. The technology's evolution presents a significant opportunity for pharmaceutical and medical industries, enabling the creation of targeted drugs and swift production of medical implants. It revolutionizes medical procedures, transforming the strategies of doctors and surgeons. Patient-specific 3D-printed anatomical models are now pivotal in precision medicine and personalized treatment approaches. Despite its ongoing development, additive manufacturing in healthcare is already integrated into various medical applications, offering substantial benefits to a sector under pressure for performance and cost reduction. In this review primarily emphasizes stent technology, different types of stents, highlighting its application with some potential complications. Here we also address their benefits, potential issues, effectiveness, indications, and contraindications. In future it can potentially reduce complications and help in improving patients' outcomes. 3DP technology offers the promise to customize solutions for complex CVD conditions and help or fostering a new era of precision medicine in cardiology.

Transformative applications of additive manufacturing in biomedical engineering: bioprinting to surgical innovations

This paper delves into the diverse applications and transformative impact of additive manufacturing (AM) in biomedical engineering. A detailed analysis of various AM technologies showcases their distinct capabilities and specific applications within the medical field. Special emphasis is placed on bioprinting of organs and tissues, a revolutionary area where AM has the potential to revolutionize organ transplantation and regenerative medicine by fabricating functional tissues and organs. The review further explores the customization of implants and prosthetics, demonstrating how tailored medical devices enhance patient comfort and performance. Additionally, the utility of AM in surgical planning is examined, highlighting how printed models contribute to increased surgical precision, reduced operating times, and minimized complications. The discussion extends to the 3D printing of surgical instruments, showcasing how these bespoke tools can improve surgical outcomes. Moreover, the integration of AM in drug delivery systems, including the development of innovative drug-loaded implants, underscores its potential to enhance therapeutic efficacy and reduce side effects. It also addresses personalized prosthetic implants, regulatory frameworks, biocompatibility concerns, and the future potential of AM in global health and sustainable practices.

Perspectives on 3D printed personalized medicines for pediatrics

In recent years, the rapid advancement of three-dimensional (3D) printing technology has yielded distinct benefits across various sectors, including pharmaceuticals. The pharmaceutical industry has particularly experienced advantages from the utilization of 3D-printed medications, which have invigorated the development of tailored drug formulations. The approval of 3D-printed drugs by the U.S. Food and Drug Administration (FDA) has significantly propelled personalized drug delivery. Additionally, 3D printing technology can accommodate the precise requirements of pediatric drug dosages and the complexities of multiple drug combinations. This review specifically concentrates on the application of 3D printing technology in pediatric preparations, encompassing a broad spectrum of uses and refined pediatric formulations. It compiles and evaluates the fundamental principles associated with the application of 3D printing technology in pediatric preparations, including its merits and demerits, and anticipates its future progression. The objective is to furnish theoretical underpinning for 3D printing technology to facilitate personalized drug delivery in pediatrics and to advocate for its implementation in clinical settings.

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.

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.

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

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

Veering to a Continuous Platform of Fused Deposition Modeling Based 3D Printing for Pharmaceutical Dosage Forms: Understanding the Effect of Layer Orientation on Formulation Performance

Three-dimensional (3D) printing of pharmaceuticals has been centered around the idea of personalized patient-based 'on-demand' medication. Fused deposition modeling (FDM)-based 3D printing processes provide the capability to create complex geometrical dosage forms. However, the current FDM-based processes are associated with printing lag time and manual interventions. The current study tried to resolve this issue by utilizing the dynamic z-axis to continuously print drug-loaded printlets. Fenofibrate (FNB) was formulated with hydroxypropyl methylcellulose (HPMC AS LG) into an amorphous solid dispersion using the hot-melt extrusion (HME) process. Thermal and solid-state analyses were used to confirm the amorphous state of the drug in both polymeric filaments and printlets. Printlets with a 25, 50, and 75% infill density were printed using the two printing systems, i.e., continuous, and conventional batch FDM printing methods. Differences between the two methods were observed in the breaking force required to break the printlets, and these differences reduced as the infill density went up. The effect on in vitro release was significant at lower infill densities but reduced at higher infill densities. The results obtained from this study can be used to understand the formulation and process control strategies when switching from conventional FDM to the continuous printing of 3D-printed dosage forms.

Improving drug release rate, drug-polymer miscibility, printability and processability of FDM 3D-printed tablets by weak acid-base interaction

Slow drug release, low drug-polymer miscibility, poor printability of polymers used, and high processing temperature are major challenges in developing FDM 3D-printed tablets. These challenges were addressed in this investigation by having a model basic drug, haloperidol (mp: 151.5 °C), interact with a weak acid, malic acid (mp: 130 °C), during the melt extrusion of formulations into filaments used for 3D-printing. Malic acid was selected as it was previously reported that it did not form any crystalline salt with haloperidol but its addition to aqueous media could greatly increase the solubility of haloperidol from ∼ 1 µg/mL to > 1 g per mL of water by acid-base supersolubilization. Concentrated solutions of haloperidol-malic acid mixtures produced amorphous materials upon drying. It has been observed in the present investigation that similar interaction between haloperidol and malic acid may also occur in the absence of water. Upon heating, haloperidol-malic acid mixtures at 1:1 and 1:2 molar ratios turned amorphous starting at ∼ 50 °C, which is much below the melting point of either component. When Kollidon® VA64, a brittle and non-printable polymer, was used as the polymeric carrier, the acid-base interaction greatly reduced the melt viscosity of haloperidol-malic acid-Kollidon® VA64 ternary mixtures. Consequently, melt extrusion of filaments and printing of tablets using such mixtures could be performed at much lower temperatures than those with haloperidol-Kollidon® VA64 binary mixtures. The filaments containing 15 % and 30 % haloperidol along with malic acid and Kollidon® VA64 could be printed into tablets at relatively low temperatures of 125 and 100 °C, respectively, thus making Kollidon® VA64 not only printable but also doing so at low temperatures. Up to 50 % w/w drug load in filaments was achieved without any crystallization of haloperidol or malic acid. Drug release at pH 2 and 6.8 from printed tablets with 100 % infill was 80 % in < 30 min. Thus, the acid-base interaction can successfully resolve multiple development challenges encountered with FDM 3D-printed tablets.

The Application and Challenge of Binder Jet 3D Printing Technology in Pharmaceutical Manufacturing

Three-dimensional (3D) printing is an additive manufacturing technique that creates objects under computer control. Owing to the rapid advancement of science and technology, 3D printing technology has been widely utilized in processing and manufacturing but rarely used in the pharmaceutical field. The first commercial form of Spritam® immediate-release tablet was approved by FDA in 2015, which promoted the advancement of 3D printing technology in pharmaceutical development. Three-dimensional printing technology is able to meet individual treatment demands with customized size, shape, and release rate, which overcomes the difficulties of traditional pharmaceutical technology. This paper intends to discuss the critical process parameters of binder jet 3D printing technology, list its application in pharmaceutical manufacturing in recent years, summarize the still-open questions, and demonstrate its great potential in the pharmaceutical industry.

Novel 3D Printed Modular Tablets Containing Multiple Anti-Viral Drugs: a Case of High Precision Drop-on-Demand Drug Deposition

3D printed drug delivery systems have gained tremendous attention in pharmaceutical research due to their inherent benefits over conventional systems, such as provisions for customized design and personalized dosing. The present study demonstrates a novel approach of drop-on-demand (DoD) droplet deposition to dispense drug solutions precisely on binder jetting-based 3D printed multi-compartment tablets containing 3 model anti-viral drugs (hydroxychloroquine sulfate - HCS, ritonavir and favipiravir). The printing pressure affected the printing quality whereas the printing speed and infill density significantly impacted the volume dispersed on the tablets. Additionally, the DoD parameters such as nozzle valve open time and cycle time affected both dispersing volume and the uniformity of the tablets. The solid-state characterization, including DSC, XRD, and PLM, revealed that all drugs remained in their crystalline forms. Advanced surface analysis conducted by microCT imaging as well as Artificial Intelligence (AI)/Deep Learning (DL) model validation showed a homogenous drug distribution in the printed tablets even at ultra-low doses. For a four-hour in vitro drug release study, the drug loaded in the outer layer was released over 90%, and the drug incorporated in the middle layer was released over 70%. In contrast, drug encapsulated in the core was only released about 40%, indicating that outer and middle layers were suitable for immediate release while the core could be applied for delayed release. Overall, this study demonstrates a great potential for tailoring drug release rates from a customized modular dosage form and developing personalized drug delivery systems coupling different 3D printing techniques.

Clinical Application of Digital 3D Reconstruction and 3D Printing Technology in Endometrial Cancer (EC) Surgery

Aims

We use CTA and magnetic resonance data to use digital three-dimensional reconstruction and 3D printing technology to reproduce the solid replication of the uterus and surrounding tissues in vitro, fully evaluate the adjacency of tumor tissues with surrounding important organs, blood vessels, and lymph nodes, and reduce the impact. The normal organ structure and function of the surgeon can shorten the operation time, reduce the bleeding during the operation, and reduce the perioperative complications of the patient to improve the prognosis of the patient.

Materials and Methods

Select 40 EC patients and divide them into group A (3D reconstruction data is transmitted to 3D printing equipment according to the results of CTA and MRI examination, and a 3D model is printed out according to the ratio of 1 : 1 for evaluation and judgment before surgery) and group B (according to MRI imaging examination, there were 20 cases each). Different surgical conditions, quality of life, adverse reactions, and clinical efficacy were evaluated in each group.

Results

The operation time, the time of the first anus exhaust, the hospitalization time after the operation, and the blood loss of the operation in group A were significantly lower than those in group B. Statistics showed that the difference was significant (P < 0.05). The quality of life scores of emotion, cognition, society, and overall health of group A were significantly higher than those of group B, while physical score, fatigue, nausea, vomiting, and pain were lower than those of group B, which were statistically significant (P < 0.05). Both groups of patients had complications after the operation, and they were asked to be followed up at the outpatient clinic 3 months after the operation. All patients recovered well. There were 19 and 18 patients in groups A and B, respectively, complaining of improvement in clinical symptoms, and the difference was not statistically significant (P < 0.05).

Conclusion

With the support of digital three-dimensional reconstruction and 3D printing technology, complex operations can be accurately performed, improving the efficacy and safety of patients after EC surgery, improving patient outcomes and quality of life, improving EC positioning accuracy, and reducing tumor residue.

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

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

Development of Composite, Reinforced, Highly Drug-Loaded Pharmaceutical Printlets Manufactured by Selective Laser Sintering-In Search of Relevant Excipients for Pharmaceutical 3D Printing

3D printing by selective laser sintering (SLS) of high-dose drug delivery systems using pure brittle crystalline active pharmaceutical ingredients (API) is possible but impractical. Currently used pharmaceutical grade excipients, including polymers, are primarily designed for powder compression, ensuring good mechanical properties. Using these excipients for SLS usually leads to poor mechanical properties of printed tablets (printlets). Composite printlets consisting of sintered carbon-stained polyamide (PA12) and metronidazole (Met) were manufactured by SLS to overcome the issue. The printlets were characterized using DSC and IR spectroscopy together with an assessment of mechanical properties. Functional properties of the printlets, i.e., drug release in USP3 and USP4 apparatus together with flotation assessment, were evaluated. The printlets contained 80 to 90% of Met (therapeutic dose ca. 600 mg), had hardness above 40 N (comparable with compressed tablets) and were of good quality with internal porous structure, which assured flotation. The thermal stability of the composite material and the identity of its constituents were confirmed. Elastic PA12 mesh maintained the shape and structure of the printlets during drug dissolution and flotation. Laser speed and the addition of an osmotic agent in low content influenced drug release virtually not changing composition of the printlet; time to release 80% of Met varied from 0.5 to 5 h. Composite printlets consisting of elastic insoluble PA12 mesh filled with high content of crystalline Met were manufactured by 3D SLS printing. Dissolution modification by the addition of an osmotic agent was demonstrated. The study shows the need to define the requirements for excipients dedicated to 3D printing and to search for appropriate materials for this purpose.

3D printing of pharmaceutical oral solid dosage forms by fused deposition: the enhancement of printability using plasticised HPMCAS

3D printing (3DP) by fused deposition modelling (FDM) is one of the most extensively developed methods in additive manufacturing. Optimizing printability by improving feedability, nozzle extrusion, and layer deposition is crucial for manufacturing solid oral dosage forms with desirable properties. This work aimed to use HPMCAS (Affinisol^TM HPMCAS 716) to prepare filaments for FDM-3DP using hot-melt extrusion (HME). It explored and demonstrated the effect of HME-filament composition and fabrication on printability by evaluating thermal, mechanical, and thermo-rheological properties. It also showed that the HME-Polymer filament composition used in FDM-3DP manufacture of oral solid dosage forms provides a tailored drug release profile. HME (HAAKE MiniLab) and FDM-3DP (MakerBot) were used to prepare HME-filaments and printed objects, respectively. Two diverse ways of improving the mechanical properties of HME-filaments were deduced by changing the formulation to enable feeding through the roller gears of the printer nozzle. These include plasticizing the polymer and adding an insoluble structuring agent (talc) into the formulation. Experimental feedability was predicted using texture analysis results was a function of PEG concentration, and glass-transition temperature (T_g) values of HME-filaments. The effect of high HME screw speed (100 rpm) resulted in inhomogeneity of HME-filament, which resulted in inconsistency of the printer nozzle extrudate and printed layers. The variability of the glass-transition temperature (T_g) of the HME-filament supported by scanning electron microscopy (SEM) images of nozzle extrudates and the lateral wall of the printed tablet helped explain this result. The melt viscosity of HPMCAS formulations was investigated using a capillary rheometer. The high viscosity of unplasticized HPMCAS was concluded to be an additional restriction for nozzle extrusion. The plasticization of HPMCAS and the addition of talc into the formulation were shown to improve thickness consistency of printed layers (using homogeneous HME-filaments). A good correlation (R²=0.9546) between the solidification threshold (low-frequency oscillation test determined by parallel-plate rheometer) and T_g of HME-filaments was also established. Drug-loaded and placebo HPMCAS-based formulations were shown to be successfully printed, with the former providing tailored drug release profiles based on variation of internal geometry (infill).

Floating Ricobendazole Delivery Systems: A 3D Printing Method by Co-Extrusion of Sodium Alginate and Calcium Chloride

At present, the use of benzimidazole drugs in veterinary medicine is strongly limited by both pharmacokinetics and formulative issues. In this research, the possibility of applying an innovative semi-solid extrusion 3D printing process in a co-axial configuration was speculated, with the aim of producing a new gastro-retentive dosage form loaded with ricobendazole. To obtain the drug delivery system (DDS), the ionotropic gelation of alginate in combination with a divalent cation during the extrusion was exploited. Two feeds were optimized in accordance with the printing requirements and the drug chemical properties: the crosslinking ink, i.e., a water ethanol mixture containing CaCl₂ at two different ratios 0.05 M and 0.1 M, hydroxyethyl cellulose 2% w/v, Tween 85 0.1% v/v and Ricobendazole 5% w/v; and alginate ink, i.e., a sodium alginate solution at 6% w/v. The characterization of the dried DDS obtained from the extrusion of gels containing different amounts of calcium chloride showed a limited effect on the ink extrudability of the crosslinking agent, which on the contrary strongly influenced the final properties of the DDS, with a difference in the polymeric matrix toughness and resulting effects on floating time and drug release.

Polymeric long-acting drug delivery systems (LADDS) for treatment of chronic diseases: Inserts, patches, wafers, and implants

Non-oral long-acting drug delivery systems (LADDS) encompass a range of technologies for precisely delivering drug molecules into target tissues either through the systemic circulation or via localized injections for treating chronic diseases like diabetes, cancer, and brain disorders as well as for age-related eye diseases. LADDS have been shown to prolong drug release from 24 h up to 3 years depending on characteristics of the drug and delivery system. LADDS can offer potentially safer, more effective, and patient friendly treatment options compared to more invasive modes of drug administration such as repeated injections or minor surgical intervention. Whilst there is no single technology or definition that can comprehensively embrace LADDS; for the purposes of this review, these systems include solid implants, inserts, transdermal patches, wafers and in situ forming delivery systems. This review covers common chronic illnesses, where candidate drugs have been incorporated into LADDS, examples of marketed long-acting pharmaceuticals, as well as newly emerging technologies, used in the fabrication of LADDS.

Opportunities and challenges of three-dimensional printing technology in pharmaceutical formulation development

Three-dimensional printing is a technology that prints the products layer-by-layer, in which materials are deposited according to the digital model designed by computer aided design (CAD) software. This technology has competitive advantages regarding product design complexity, product personalization, and on-demand manufacturing. The emergence of 3D technology provides innovative strategies and new ways to develop novel drug delivery systems. This review summarizes the application of 3D printing technologies in the pharmaceutical field, with an emphasis on the advantages of 3D printing technologies for achieving rapid drug delivery, personalized drug delivery, compound drug delivery and customized drug delivery. In addition, this article illustrates the limitations and challenges of 3D printing technologies in the field of pharmaceutical formulation development.

Development of FDM 3D-printed tablets with rapid drug release, high drug-polymer miscibility and reduced printing temperature by applying the acid-base supersolubilization (ABS) principle

Some of the major issues with the development of FDM 3D printed tablets are slow drug release, lack of drug-polymer miscibility, high processing temperature, and poor printability. In this investigation, these issues were addressed by using a novel physicochemical principle called acid-base supersolubilization (ABS) previously developed in our laboratory. The aqueous solubility of a basic drug, haloperidol, was increased to ~300 mg/g of solution by adding glutaric acid, and, upon drying, the concentrated solutions produced amorphous materials. Similar amorphous systems could also be produced by heating haloperidol-glutaric acid mixtures. Filaments for 3D printing were prepared by melt extrusion of formulations containing 15% w/w haloperidol and 10.5% glutaric acid (1:2 M ratio) along with 74.5% polymers, such as Kollidon® VA64 alone or its mixtures with Affinisol™ 15cP. Filaments could be extruded and printed at low temperatures of 115 and 120 °C, respectively. Haloperidol was fully miscible in the formulations because of the acid-base interaction and formed amorphous systems even at higher drug loads. Although filaments of haloperidol-Kollidon® VA64 mixtures by themselves cannot be printed, the printability of formulation improved such that those containing glutaric acid were printable. Drug release rates from the formulations at pH 2 and 6.8 were rapid and complete.

Exploration and evaluation of dynamic dose-control platform for pediatric medicine based on Drop-on-Powder 3D printing technology

Patient responses to doses vary widely, and affording limited doses to such a diverse population will inevitably yield unsatisfactory therapeutic effects and even adverse effects. In Particular, there is an urgent demand for a dynamic dose-control platform for pediatric patients, many of whom require diverse doses and flexible dose adjustments. The aim of this study was to explore the possibility of using a drop-on-powder (DoP) technology-based desktop 3D printer to build a dynamic dose-control platform for theophylline (TP) and metoprolol tartrate (MT). In addition, the impact of drug loading patterns on the accuracy of dose regulation was also assessed. All of the printed tablets exhibited good mechanical properties and satisfactory structural integrity. On printing tablets with target drug doses, the accuracy was in the range of 91.2~108% with a small variation coefficient in the range of 0.5~3.2%. Compared with traditional divided-dose methods, drop-on-powder 3D printing technology exhibited higher accuracy in dose regulation, but had less impact on the in vitro drug release behavior. The results in this work clearly indicate the possibility and ability of DoP technology as a promising method for constructing a dynamic dose-control platform for the fabrication of personalized medicines for pediatric patients.

3D printing technology as innovative solutions for biomedical applications

3D printing was once predicted to be the third industrial revolution. Today, the use of 3D printing is found across almost all industries. This article discusses the latest 3D printing applications in the biomedical industry.