Influence of the geometry of 3D printed solid oral dosage forms on their swallowability

From design to 3D printing: A proof-of-concept study for multiple unit particle systems (MUPS) printed by dual extrusion fused filament fabrication

MUPS (multiple unit particle systems) are oral dosage forms consisting of small particles which are filled into capsules or compressed into tablets. Compared to monolithic sustained-release tablets, MUPS tablets rapidly disintegrate inside the stomach releasing the contained small particles, which can be emptied from the stomach independent of housekeeping waves. Control of release can be achieved by adapting the particle composition. Despite the advantages of MUPS, only a limited number of preparations are available on the market. 3D printing could be a new advantageous method to produce MUPS tablets compared to the conventional production via tableting. Due to the increasing research interest in personalised medicine, especially regarding dose adjustments, this flexible production approach could be a promising concept. Therefore, this work proposes a concept for printing MUPS tablets using a dual extrusion fused filament fabrication 3D printer. The general idea is that the two print heads can be used independently to print a water-soluble tablet shell with the first print head and incorporate functional particles into the tablet shell with a second print head using different materials for each step. In this study, a modular four-particle-layered tablet computer model containing 196 cylindrical particles with a diameter of 1.4 mm, a height of 1.0 mm and a total tablet size of 22.6 × 8.5 × 6.0 mm is proposed. A first proof-of-concept study with drug-free commercially available polylactic acid filament for the particles and polyvinyl alcohol filament for the tablet shell revealed critical parameters (such as filament retraction, z-offset and water content of filaments) for the successful printing of the proposed computer model. In addition, the successfully printed model 3D-MUPS tablets and incorporated particles were characterised, revealing a reproducible manufacturing process. The printed model particles had a diameter of 1.27 ± 0.04 mm and a height of 1.05 ± 0.01 mm. One of the challenges of the new approach was to avoid particle agglomeration because of remelting processes during the printing with two print heads. 57.54 ± 18.59 % of the 196 printed particles were present as single particles. Finally, the transferability and suitability with a model API-loaded (paracetamol) hydroxypropyl methylcellulose filament for the particles and a polyvinyl alcohol tablet shell was successfully tested. On average, 80 % of paracetamol was released within 3 h (2-4 h). Overall, this work shows an innovative new manufacturing method for dose-adjustable personalised MUPS tablets but also considers new challenges arising from the different manufacturing processes.

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.

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

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

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

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

Parameters to Consider for Successful Medication Use in Older Adults - an AGePOP Review

Older adults are the main users of medicine and due to their multimorbidity are often faced/confronted with a complex medication management. This review article provides a brief overview on aspects of medication management such as maintaining a stock of the required medicine, understanding and following the instructions for use, coping with the primary and secondary packaging as well as preparation prior to use. The main focus however is on the drug intake itself and provides an overview about the current understanding of real life dosing conditions of older adults and geriatric patients. Furthermore, it elaborates the acceptability of dosage forms, in particular solid oral dosage forms as they represent the majority of dosage forms taken by these patient populations. An improved understanding of the needs of older adults and geriatric patients, their acceptability of various dosage forms and the circumstances under which they manage their medications, will make the design of more patient-centric drug products possible.

Impact of Tablet Size and Shape on the Swallowability in Older Adults

Older adults represent the major target population for oral medications, due to the high prevalence of multimorbidity. To allow for successful pharmacological treatments, patients need to adhere to their medication and, thus, patient-centric drug products with a high level of acceptability by the end users are needed. However, knowledge on the appropriate size and shape of solid oral dosage forms, as the most commonly used dosage forms in older adults, is still scarce. A randomized intervention study was performed including 52 older adults (65 to 94 years) and 52 young adults (19 to 36 years). Each participant swallowed four coated placebo tablets differing in weight (250 to 1000 mg) and shape (oval, round, oblong) in a blinded manner on three study days. The choice of tablet dimensions allowed for a systematic comparison between different tablet sizes of the same shape, as well as between different tablet shapes. Swallowability was assessed using a questionnaire-based method. All tested tablets were swallowed by ≥80% of adults, independent of age. However, only the 250 mg oval tablet was classified as well swallowable by ≥80% of old participants. The same was true for young participants; however, they also considered the 250 mg round and the 500 mg oval tablet as well swallowable. Furthermore, swallowability was seen to influence the willingness to take a tablet on a daily basis, especially for an intake over longer time periods.

Development and Bioequivalence of 3D-Printed Medication at the Point-of-Care: Bridging the Gap Toward Personalized Medicine

Personalized medicine is currently hampered by the lack of flexible drug formulations. Especially for pediatric patients, manual compounding of personalized drug formulations by pharmacists is required. Three-Dimensional (3D) printing of medicines, which enables small-scale manufacturing at the point-of-care, can fulfill this unmet clinical need. This study investigates the feasibility of developing a 3D-printed tablet formulation at the point-of-care which complies to quality requirements for clinical practice, including bioequivalence. Development, manufacturing, and quality control of the 3D-printed tablets was performed at the manufacturing facility and laboratory of the department of Clinical Pharmacy and Toxicology at Leiden University Medical Center. Sildenafil was used as a model drug for the tablet formulation. Along with the 3D-printed tablets a randomized, an open-label, 2-period, crossover, single-dose clinical trial to assess bioequivalence was performed in healthy adults. Bioequivalence was established if areas under the plasma concentration curve from administration to the time of the last quantifiable concentration (AUC_0-t ) and maximum plasma concentration (C_max ) ratios were within the limits of 80.00-125.00%. The manufacturing process provided reproducible 3D-printed tablets that adhered to quality control requirements and were consequently used in the clinical trial. The clinical trial was conducted in 12 healthy volunteers. The 90% confidence intervals (CIs) of both AUC_0-t and C_max ratios were within bioequivalence limits (AUC_0-t 90% CI: 87.28-104.14; C_max 90% CI: 80.23-109.58). For the first time, we demonstrate the development of a 3D-printed tablet formulation at the point-of-care that is bioequivalent to its marketed originator. The 3D printing of personalized formulations is a disruptive technology for compounding, bridging the gap toward personalized medicine.

Hybrid Manufacturing of Oral Solid Dosage Forms via Overprinting of Injection-Molded Tablet Substrates

Since 3D printing allows for patient-specific dosage forms, it has become a major focus in pharmaceutical research. However, it is difficult to scale up drug product manufacturing. Injection molding has been used in conjunction with hot-melt extrusion to mass produce drug products, but making tailored solid dosage forms with this technology is neither cost-effective nor simple. This study explored the use of a combination of fused filament fabrication and injection molding to create patient-specific solid dosage forms. A tablet fixation and location template was used to overprint directly on injection-molded tablet bases, and theophylline was combined with polycaprolactone and Kollidon^® VA64 via hot-melt extrusion to produce the filament. Dynamic mechanical analysis was used to evaluate the brittleness of the filament, and differential scanning calorimetry was used to analyze the thermal results. The results showed that theophylline had a flow promoting effect on the polymer blend and that overprinted tablets were manufactured faster than 3D-printed tablets. Drug release studies also showed that overprinted tablets released faster than injection-molded tablets. This method demonstrates the potential of hybrid manufacturing for the pharmaceutical industry as a means of bridging the gap between personalized dosage forms and mass production.

Accelerating 3D printing of pharmaceutical products using machine learning

Three-dimensional printing (3DP) has seen growing interest within the healthcare industry for its ability to fabricate personalized medicines and medical devices. However, it may be burdened by the lengthy empirical process of formulation development. Active research in pharmaceutical 3DP has led to a wealth of data that machine learning could utilize to provide predictions of formulation outcomes. A balanced dataset is critical for optimal predictive performance of machine learning (ML) models, but data available from published literature often only include positive results. In this study, in-house and literature-mined data on hot melt extrusion (HME) and fused deposition modeling (FDM) 3DP formulations were combined to give a more balanced dataset of 1594 formulations. The optimized ML models predicted the printability and filament mechanical characteristics with an accuracy of 84%, and predicted HME and FDM processing temperatures with a mean absolute error of 5.5 °C and 8.4 °C, respectively. The performance of these ML models was better than previous iterations with a smaller and a more imbalanced dataset, highlighting the importance of providing a structured and heterogeneous dataset for optimal ML performance. The optimized models were integrated in an updated web-application, M3DISEEN, that provides predictions on filament characteristics, printability, HME and FDM processing temperatures, and drug release profiles (https://m3diseen.com/predictionsFDM/). By simulating the workflow of preparing FDM-printed pharmaceutical products, the web-application expedites the otherwise empirical process of formulation development, facilitating higher pharmaceutical 3DP research throughput.

4D prints of flexible dosage forms using thermoplastic polyurethane with hybrid shape memory effect

Thermoplastic polyurethanes are versatile materials due to their flexible and elastic properties. In research, medicine, and pharmacy, they are used in dosage forms, implants or as components of medical devices. To gain a deeper understanding of the influences on unfolding or expanding dosage forms, in this publication, 3D printing was used to produce differently shaped and foldable objects from various technical thermoplastic polyurethane filaments. The shape memory behaviour of the dosage forms was exploited to fold and package them in water-soluble hard gelatin capsules. The unfolding time and dimensional recovery of the 3D printed dosage forms were investigated as a function of material properties and shape. As an example, for the use of flexible dosage forms, 3D models have been designed so that their unfolded size is suitable for possible gastric retention. Depending on the shape and material, different unfolding behaviours could be shown. Over a storage period of 60 days, a time related stress on the 4D printed objects was evaluated, which possibly affects the unfolding process. The results of this work aim to be used to evaluate the behaviour of 3D printed unfolding and expanding dosage forms and how they may be suitable for the development of innovative sustained drug delivery concepts or medicinal devices. The basic principle of a hybrid shape memory effect used here could possibly be applied to other drug delivery strategies besides gastric retention.

3D Printing of Paracetamol Suppositories: An Automated Manufacturing Technique for Individualized Therapy

Pharmaceutical compounding using the molding technique is the currently applied method for the on-demand manufacturing of suppositories and pessaries. Potential errors of this method are difficult to detect, and the possibilities of individualization of size and shape of the suppositories are limited. In this study, a syringe-based semi-solid 3D printing technique was developed for the manufacturing of suppositories in three different printing designs with the suppository bases polyethylene glycol (PEG) and hard fat (HF). The 3D printed suppositories were analyzed for their visual appearance, uniformity of mass and content, diametrical dimension, breaking force and release behavior and compared to suppositories of the same composition prepared by a commonly used molding technique. The results showed no adverse properties for the 3D printed suppositories compared to the molded ones. Moreover, the easy adaptation of shape using the 3D printing technique was demonstrated by the printing of different sizes and infill structures. Thus, 3D printing has great potential to complement the available manufacturing methods for compounded suppositories, as it represents an automated system for the individualized manufacturing of suppositories that meet patients' needs.

The Advent of a New Era in Digital Healthcare: A Role for 3D Printing Technologies in Drug Manufacturing?

The technological revolution has physically affected all manufacturing domains, at the gateway of the fourth industrial revolution. Three-dimensional (3D) printing has already shown its potential in this new reality, exhibiting remarkable applications in the production of drug delivery systems. As part of this concept, personalization of the dosage form by means of individualized drug dose or improved formulation functionalities has concentrated global research efforts. Beyond the manufacturing level, significant parameters must be considered to promote the real-time manufacturing of pharmaceutical products in distributed areas. The majority of current research activities is focused on formulating 3D-printed drug delivery systems while showcasing different scenarios of installing 3D printers in patients' houses, hospitals, and community pharmacies, as well as in pharmaceutical industries. Such research presents an array of parameters that must be considered to integrate 3D printing in a future healthcare system, with special focus on regulatory issues, drug shortages, quality assurance of the product, and acceptability of these scenarios by healthcare professionals and public parties. The objective of this review is to critically present the spectrum of possible scenarios of 3D printing implementation in future healthcare and to discuss the inevitable issues that must be addressed.