Direct Powder Extrusion of Paracetamol Loaded Mixtures for 3D Printed Pharmaceutics for Personalized Medicine via Low Temperature Thermal Processing

Sex-specific formulations of doxazosin mesylate via direct powder extrusion 3D printing

Males and females are known to exhibit significant differences in drug pharmacokinetics and pharmacodynamics, which are still overlooked in pharmaceutical research and development. These disparities contribute to adverse effects and increased mortality in females, highlighting the critical need for sex-specific formulations. Extended-release formulations of doxazosin mesylate, an alpha blocker used to treat hypertension, have shown significant sex-based differences in pharmacokinetics, leading to heightened adverse effects in females and rendering current titration recommendations impractical. This study explored the potential of a 3D printing (3DP) technology, direct powder extrusion (DPE), for producing personalised, sex-specific doses of doxazosin mesylate. A simple three component formulation was made composed of hydroxypropyl cellulose (HPC) polymer Klucel JF, D-mannitol, and doxazosin mesylate. Extended-release printlets of varying doses (1, 2, and 3 mg) were manufactured from a single 1% w/w doxazosin pharma-ink batch, enabling easy dose personalisation by adjusting the printlet dimensions. The use of a single pharma-ink supports the technology's ease of use in a pharmacy setting, by eliminating frequent pharma-ink changes during the pharmaceutical compounding process. In vitro dissolution testing revealed an extended drug release profile, influenced by surface-area-to-volume (SA: V) ratios. Introducing channels in larger printlets standardized the SA: V ratios, enhancing release profile uniformity. Release kinetics followed the Hixson-Crowell and Korsmeyer-Peppas models, indicating diffusion and polymer swelling mechanisms. This work highlights the capability of DPE 3DP for creating personalized, extended-release oral dosage forms, supporting precise dose customization for patient-specific therapy. Graphical Abstract.

The Future of Medicine: How 3D Printing Is Transforming Pharmaceuticals

Three-dimensional printing technology is transforming pharmaceutical manufacturing by shifting from conventional mass production to additive manufacturing, with a strong emphasis on personalized medicine. The integration of bioinks and AI-driven optimization is further enhancing this innovation, enabling drug production with precise dosages, tailored drug-release profiles, and unique multi-drug combinations that respond to individual patient needs. This advancement is significantly impacting healthcare by accelerating drug development, encouraging innovative pharmaceutical designs, and enhancing treatment efficacy. Traditional pharmaceutical manufacturing follows a one-size-fits-all approach, which often fails to meet the specific requirements of patients with unique medical conditions. In contrast, 3D printing, coupled with bioink formulations, allows for on-demand drug production, reducing dependency on large-scale manufacturing and storage. AI-powered design and process optimization further refine dosage forms, printability, and drug release mechanisms, ensuring precision and efficiency in drug manufacturing. These advancements have the potential to lower overall healthcare costs while improving patient adherence to medication regimens. This review explores the potential, challenges, and environmental benefits of 3D pharmaceutical printing, positioning it as a key driver of next-generation personalized medicine.

3D printing of pharmaceutical dosage forms: Recent advances and applications

Three-dimensional (3D) printing, also referred to as additive manufacturing, is considered to be a game-changing technology in many industries and is also considered to have potential use cases in pharmaceutical manufacturing, especially if individualization is desired. In this review article the authors systematically researched literature published during the last 5 years (2019 - spring 2024) on the topic of 3D printed dosage forms. Besides all kinds of oral dosage forms ranging from tablets and capsules to films, pellets, etc., numerous reports were also identified on parenteral and cutaneous dosage forms and also rectal, vaginal, dental, intravesical, and ophthalmic preparations. In total, more than 500 publications were identified and grouped according to the site of administration, and an overview of the manuscripts is presented here. Furthermore, selected publications are described and discussed in more detail. The review highlights the very different approaches that are currently used in order to develop 3D printed dosage forms but also addresses remaining challenges.

Extrusion-Based 3D Printing of Pharmaceuticals-Evaluating Polymer (Sodium Alginate, HPC, HPMC)-Based Ink's Suitability by Investigating Rheology

Three-dimensional printing is promising in the pharmaceutical industry for personalized medicine, on-demand production, tailored drug loading, etc. Pressure-assisted microsyringe (PAM) printing is popular due to its low cost, simple operation, and compatibility with heat-sensitive drugs but is limited by ink formulations lacking the essential characteristics, impacting their performance. This study evaluates inks based on sodium alginate (SA), hydroxypropyl cellulose (HPC H), and hydroxypropyl methylcellulose (HPMC K100 and K4) for PAM 3D printing by analyzing their rheology. The formulations included the model drug Fenofibrate, functional excipients (e.g., mannitol, polyethylene glycol, etc.), and water or water-ethanol mixtures. Pills and thin films as an oral dosage were printed using a 410 μm nozzle, a 10 mm/s speed, a 50% infill density, and a 60 kPa pressure. Among the various formulated inks, only the ink containing 0.8% SA achieved successful prints with the desired shape fidelity, linked to its rheological properties, which were assessed using flow, amplitude sweep, and thixotropy tests. This study concludes that (i) an ink's rheological properties-viscosity, shear thinning, viscoelasticity, modulus, flow point, recovery, etc.-have to be considered to determine whether it will print well; (ii) printability is independent of the dosage form; and (iii) the optimal inks are viscoelastic solids with specific rheological traits. This research provides insights for developing polymer-based inks for effective PAM 3D printing in pharmaceuticals.

Optimising 3D printed medications for rare diseases: In-line mass uniformity testing in direct powder extrusion 3D printing

Biotinidase deficiency is a rare inherited disorder characterized by biotin metabolism issues, leading to neurological and cutaneous symptoms that can be alleviated through biotin administration. Three-dimensional (3D) printing (3DP) offers potential for personalized medicine production for rare diseases, due to its flexibility in designing dosage forms and controlling release profiles. For such point-of-care applications, rigorous quality control (QC) measures are essential to ensure precise dosing, optimal performance, and product safety, especially for low personalized doses in preclinical and clinical studies. In this work, we addressed QC challenges by integrating a precision balance into a direct powder extrusion pharmaceutical 3D printer (M3DIMAKER™) for real-time, in-line mass uniformity testing, a critical quality control step. Small and large capsule-shaped biotin printlets (3D printed tablets) for immediate- and extended-release were printed. The integrated balance monitored and registered each printlet's weight, identifying any deviations from acceptable limits. While all large printlet batches met mass uniformity criteria, some small printlet batches exhibited weight deviations. In vitro release studies showed large immediate-release printlets releasing 82% of biotin within 45 min, compared to 100% for small immediate-release printlets. For extended-release formulations, 35% of the drug was released from small printlets, whereas 24% was released from large printlets at the same time point. The integration of process analytical technology tools in 3DP shows promise in enhancing QC and scalability of personalized dosing at the point-of-care, demonstrating successful integration of a balance into a direct powder extrusion 3D printer for in-line mass uniformity testing across different sizes of capsule-shaped printlets.

Concept and Evolution in 3D Printing for Excellence in Healthcare

Three-dimensional printing (3DP) has gained popularity among scientists and researchers in every field due to its potential to drastically reduce energy costs for the production of customized products by utilizing less energy-intensive machines as well as minimizing material waste. The 3D printing technology is an additive manufacturing approach that uses material layer-by-layer fabrication to produce the digitally specified 3D model. The use of 3D printing technology in the pharmaceutical sector has the potential to revolutionize research and development by providing a quick and easy means to manufacture personalized one-off batches, each with unique dosages, distinct substances, shapes, and sizes, as well as variable release rates. This overview addresses the concept of 3D printing, its evolution, and its operation, as well as the most popular types of 3D printing processes utilized in the health care industry. It also discusses the application of these cutting-edge technologies to the pharmaceutical industry, advancements in various medical fields and medical equipment, 3D bioprinting, the most recent initiatives to combat COVID-19, regulatory frameworks, and the major challenges that this technology currently faces. In addition, we attempt to provide some futuristic approaches to 3DP applications.

Feasibility study of the use of a homemade direct powder extrusion printer to manufacture printed tablets with an immediate release of a BCS II molecule

Among the various 3D printing techniques, FDM is the most studied in pharmaceutical research. However, it requires the fabrication of filaments with suitable mechanical properties using HME, which can be laborious and time-consuming. DPE has emerged as a single-step printing technique that can overcome FDM limits as it enables the direct printing of powder blends without the need of filaments. This study demonstrated the manufacturing of cylindrical-shaped printed tablets containing CBD, a BCS II molecule, with an immediate release. Different blends of PEO/E100 and PEO/SOL, each with 10 % of CBD, were printed and tested according to the Eur. Ph. for uncoated tablets. Each printed cylinder met the Eur. Ph. specifications for friability, mass variation and mass uniformity. However, only the E100-based formulations enabled a CBD immediate release, as formulations containing SOL formed a gel once in contact with the dissolution medium, reducing the drug dissolution rate.

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.

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

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

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

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

Recent advances in wearable medical diagnostic sensors and new therapeutic dosage forms for fever in children

Fever in children is one of the most common symptoms of pediatric diseases and the most common complaint in pediatric clinics, especially in the emergency department. Diseases such as pneumonia, sepsis, and meningitis are leading causes of death in children, and the early manifestations of these diseases are accompanied by fever symptoms. Accurate diagnosis and real-time monitoring of the status of febrile children, rapid and effective identification of the cause, and treatment can have a positive impact on relieving their symptoms and improving their quality of life. In recent years, wearable diagnostic sensors have attracted special attention for their high flexibility, real-time monitoring, and sensitivity. Temperature sensors and heart rate sensors have provided new advances in detecting children's body temperature and heart rate. Furthermore, some novel formulations have also received wide attention for addressing bottlenecks in medication administration for febrile children, such as difficulty in swallowing and inaccurate dosing. In this context, the present review provides recent advances of novel wearable medical sensor devices for diagnosing fever. Moreover, the application progress of innovative dosage forms of classical antipyretic drugs for children is presented. Finally, challenges and prospects of wearable sensor-based diagnostics and novel agent-based treatment of fever in children are discussed in brief.

Development of Advanced 3D-Printed Solid Dosage Pediatric Formulations for HIV Treatment

The combination of lopinavir/ritonavir remains one of the first-line therapies for the initial antiretroviral regimen in pediatric HIV-infected children. However, the implementation of this recommendation has faced many challenges due to cold-chain requirements, high alcohol content, and unpalatability for ritonavir-boosted lopinavir syrup. In addition, the administration of crushed tablets has shown a detriment for the oral bioavailability of both drugs. Therefore, there is a clinical need to develop safer and better formulations adapted to children’s needs. This work has demonstrated, for the first time, the feasibility of using direct powder extrusion 3D printing to manufacture personalized pediatric HIV dosage forms based on 6 mm spherical tablets. H-bonding between drugs and excipients (hydroxypropyl methylcellulose and polyethylene glycol) resulted in the formation of amorphous solid dispersions with a zero-order sustained release profile, opposite to the commercially available formulation Kaletra, which exhibited marked drug precipitation at the intestinal pH.

Direct cyclodextrin-based powder extrusion 3D printing for one-step production of the BCS class II model drug niclosamide

Niclosamide (NCS) is a drug that has been used as an anthelmintic and anti-parasitic drug for about 40 years. Recently, some studies have highlighted its potential in treating various tumors, allowing a repositioning of this drug. Despite its potential, NCS is a Biopharmaceutical Classification System (BCS) Class II drug and is consequently characterized by low aqueous solubility, poor dissolution rate and reduced bioavailability, which limits its applicability. In this work, we utilize a very novel technique, direct powder extrusion (DPE) 3D printing, which overcomes the limitations of previously used techniques (fused deposition modelling, FDM) to achieve direct extrusion of powder mixtures consisting of NCS, hydroxypropyl methylcellulose (HPMC, Affinisol 15 LV), hydroxypropyl-β-cyclodextrin (HP-β-CD) and polyethylene glycol (PEG) 6000. For the first time, direct printing of powder blends containing HP-β-CD was conducted. For all tablets, in vitro dissolution studies showed sustained drug release over 48 h, but for tablets containing HP-β-CD, the release was faster. Solid-state characterization studies showed that during extrusion, the drug lost its crystal structure and was evenly distributed within the polymer matrix. All printed tablets have exhibited good mechanical and physical features and a stability of the drug content for up to 3 months. This innovative printing technique has demonstrated the possibility to produce personalized pharmaceutical forms directly from powders, avoiding the use of filament used by FDM.

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).

The potential of natural products use in fused deposition modeling 3D printing of pharmaceutical dosage forms

In recent years, the interest in 3D printing of medicines has increased due to many advantages of this technology, such as flexibility of the dose and dosage form of the printed product. Fused deposition modeling (FDM) is one of the most popular 3D printing technologies in the pharmaceutical field, due to its low cost and simplicity. The subject of this review is the potential use of natural products as biodegradable and biocompatible materials with good safety profiles in FDM 3D printing of pharmaceuticals. Natural products such as alginate, chitosan and starch have already been employed as excipients in FDM 3D printed pharmaceutical dosage forms, while others like shellac and zein show the potential, but haven't yet been part of 3D printed pharmaceutical formulations. These excipients have different roles in the formulation of filaments for FDM 3D printing, for example as fillers, matrix carriers or drug-release modifiers. In addition, the possibility of incorporating active pharmaceutical ingredients of natural origin in filaments for FDM 3D printing was reviewed. High printing temperatures limit the use of natural products in FDM 3D printing. However, adequate selection of thermoplastic material and printing parameters can widen the use of natural products in FDM 3D printing of pharmaceutical dosage forms.

3D Printing of Thermo-Sensitive Drugs

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