3D printing of immediate-release tablets containing olanzapine by filaments extrusion

Reverse Engineering and 3D Printing of Medical Devices for Drug Delivery and Drug-Embedded Anatomic Implants

In recent years, 3D printing (3DP) has advanced traditional medical treatments. This review explores the fusion of reverse engineering and 3D printing of medical implants, with a specific focus on drug delivery applications. The potential for 3D printing technology to create patient-specific implants and intricate anatomical models is discussed, along with its ability to address challenges in medical treatment. The article summarizes the current landscape, challenges, benefits, and emerging trends of using 3D-printed formulations for medical implantation and drug delivery purposes.

A Review on Physicochemical Properties of Polymers Used as Filaments in 3D-Printed Tablets

Three-dimensional (3D) printing technology has presently been explored widely in the field of pharmaceutical research to produce various conventional as well as novel dosage forms such as tablets, capsules, oral films, pellets, subcutaneous implants, scaffolds, and vaginal rings. The use of this innovative method is a good choice for its advanced technologies and the ability to make tailored medicine specifically for individual patient. There are many 3D printing systems that are used to print tablets, implants, and vaginal rings. Among the available systems, the fused deposition modeling (FDM) is widely utilized. The FDM has been regarded as the best choice of printer as it shows high potential in the production of tablets as a unit dose in 3D printing medicine manufacturing. In order to design a 3D-printed tablet or other dosage forms, the physicochemical properties of polymers play a vital role. One should have proper knowledge about the polymer's properties so that one can select appropriate polymers in order to design 3D-printed dosage form. This review highlighted the various physicochemical properties of polymers that are currently used as filaments in 3D printing. In this manuscript, the authors also discussed various systems that are currently adopted in the 3D printing.

Biphasic drug release from electrospun structures

INTRODUCTION

Biphasic release, as a special drug-modified release profile that combines immediate and sustained release, allows fast therapeutic action and retains blood drug concentration for long periods. Electrospun nanofibers, particularly those with complex nanostructures produced by multi-fluid electrospinning processes, are potential novel biphasic drug delivery systems (DDSs).

AREAS COVERED

This review summarizes the most recent developments in electrospinning and related structures. In this review, the role of electrospun nanostructures in biphasic drug release was comprehensively explored. These electrospun nanostructures include monolithic nanofibers obtained through single-fluid blending electrospinning, core-shell and Janus nanostructures prepared via bifluid electrospinning, three-compartment nanostructures obtained via trifluid electrospinning, nanofibrous assemblies obtained through the layer-by-layer deposition of nanofibers, and the combined structure of electrospun nanofiber mats with casting films. The strategies and mechanisms through which complex structures facilitate biphasic release were analyzed.

EXPERT OPINION

Electrospun structures can provide many strategies for the development of biphasic drug release DDSs. However, many issues such as the scale-up productions of complex nanostructures, the in vivo verification of the biphasic release effects, keeping pace with the developments of multi-fluid electrospinning, drawing support from the state-of-the-art pharmaceutical excipients, and the combination with traditional pharmaceutical methods need to be addressed for real applications.

3D printed, personalized sustained release cortisol for patients with adrenal insufficiency

The standard of care for patients with Adrenal Insufficiency (AI) is suboptimal. Administration of hydrocortisone three times a day produces plasma cortisol fluctuations associated with negative health outcomes. Furthermore, there is a high inter-individual variability in cortisol need, necessitating a personalized approach. It is hypothesized that a personalized, sustained release formulation would enhance the pharmacotherapy by mimicking the physiological cortisol plasma concentration at a higher level. Therefore, a novel 24 h sustained release 3D printed (3DP) hydrocortisone formulation has been developed (M3DICORT) by coupling hot-melt extrusion with fused deposition modeling. A uniform drug distribution in the 3DP tablets is demonstrated by a content of 101.66 ± 1.60 % with an acceptance value of 4.01. Furthermore, tablets had a stable 24 h dissolution profile where the intra-batch standard deviation was ± 2.8 % and the inter-batch standard deviation was ± 6.8 %. Tablet height and hydrocortisone content were correlated (R² = 0.996), providing a tool for easy dose personalization. Tablets maintained critical quality attributes, such as dissolution profile (f2 > 60) and content uniformity after process transfer from a single-screw extruder to a twin-screw extruder. Impurities were observed in the final product which should be mitigated before clinical assessment. To our knowledge, M3DICORT is the first 3DP hydrocortisone formulation specifically developed for AI.

3D Printed Housing Devices for Segregated Compartmental Delivery of Oral Fixed-Dose Anti-Tubercular Drugs Adopting Print and Fill Strategy

World Health Organization (WHO) recommends the use of first-line anti-tuberculosis drugs, that is, rifampicin (RIF) and isoniazid (INH) fixed-dose combination (FDC) therapies in tuberculosis (TB) disease. The absorption of RIF from an FDC incorporates INH, and it is significantly compromised due to its reaction with INH, resulting in a severe loss of RIF under gastric stomach pH condition. Such reduction in the dose of both drugs from FDC formulations has been alleged to be one of the chief obstacles in effective TB treatment. This emphasizes a need to develop suitable cutting-edge advanced bioengineered delivery devices that can attenuate this severe problem to mitigate this chief obstacle. Therefore, we designed, prototyped, and characterized bioengineered 3D printed housing devices in the form of printed tablets adopting print and fill strategy for segregated compartmental delivery of RIF into the intestine (to avoid stomach gastric pH induced chemical degradation as alone and FDC) and INH into the stomach (no degradation observed as alone and FDC in stomach gastric pH conditions) for the desired treatment outcome against TB. Prepared 3D printed housings showed almost zero friability, enough hardness along weight variations <±3.0%. Different thermal and morphological analyses confirmed the insignificant changes in the nature of the polymer as before and after printing. The in vitro release for INH from polyvinyl alcohol mediated 3D printed housings showed almost 100% release within 2.5 h in acidic medium, whereas poly-lactic acid (PLA) mediated 3D printed housings continued to release RIF above 70% in the presence of physiological enzymes in alkaline medium for 432 h. The in vivo bioavailability assessment correlated with in vitro dissolution behavior for INH and RIF, whereas RIF did not release from 3D printed PLA housings in vivo.

Fused Deposition Modeling as a Possible Approach for the Preparation of Orodispersible Tablets

Additive manufacturing technologies are considered as a potential way to support individualized pharmacotherapy due to the possibility of the production of small batches of customized tablets characterized by complex structures. We designed five different shapes and analyzed the effect of the surface/mass ratio, the influence of excipients, and storage conditions on the disintegration time of tablets printed using the fused deposition modeling method. As model pharmaceutical active ingredients (APIs), we used paracetamol and domperidone, characterized by different thermal properties, classified into the various Biopharmaceutical Classification System groups. We found that the high surface/mass ratio of the designed tablet shapes together with the addition of mannitol and controlled humidity storage conditions turned out to be crucial for fast tablet’s disintegration. As a result, mean disintegration time was reduced from 5 min 46 s to 2 min 22 s, and from 11 min 43 s to 2 min 25 s for paracetamol- and domperidone-loaded tablets, respectively, fulfilling the European Pharmacopeia requirement for orodispersible tablets (ODTs). The tablet’s immediate release characteristics were confirmed during the dissolution study: over 80% of APIs were released from printlets within 15 min. Thus, this study proved the possibility of using fused deposition modeling for the preparation of ODTs.

Extraction of small molecule from human plasma by prototyping 3D printed sorbent through extruded filament for LC-MS/MS analysis

Analytical sample preparation techniques are regarded as crucial steps for analyzing compounds from different biological matrices. The development of new extraction techniques is a modern trend in the bioanalytical sciences. 3D printed techniques have emerged as a valuable technology for prototyping devices in customized shapes for a cost-effective way to advance analytical sample preparation techniques. The present study aims to fabricate customized filaments through the hot-melt extrusion (HME) technique followed by fused deposition modeling mediated 3D printing process for rapid prototyping of 3D printed sorbents to extract a sample from human plasma. Thus, we fabricated our own indigenous filament using poly (vinyl alcohol), Eudragit® RSPO, and tri-ethyl citrate through HME to prototype the fabricated filament into a 3D printed sorbent for the extraction of small molecules. The 3D sorbent was applied to extract hydrocortisone from human plasma and analyzed using a validated LC-MS/MS method. The extraction procedure was optimized, and the parameters influencing the sorbent extraction were systematically investigated. The extraction recovery of hydrocortisone was found to be >82% at low, medium, and high quality control samples, with a relative standard deviation of <2%. The intra-and inter-day precisions for hydrocortisone ranged from 1.0% to 12% and 2.0%-10.0%, respectively, whereas the intra-and inter-day accuracy for hydrocortisone ranged from 93.0% to 111.0% and 92.0% to 110.0%, respectively. The newly customizable size and shape of the 3D printed sorbent opens new possibilities for extracting small molecules from human plasma.

3D Printing: an appealing technology for the manufacturing of solid oral dosage forms

OBJECTIVES

The traditional manufacturing methods of solid oral dosage forms (SODFs) are reported to be time-consuming, highly expensive and not tailored to the patient's needs. Three-dimensional printing (3DP) is an innovative emerging technology that can help to overcome these issues. The aim of this review is to describe the most employed 3DP technologies, materials and the state of the art on 3DP SODFs. Characterization techniques of 3DP SODFs, challenges and regulatory issues are also discussed.

KEY FINDINGS

The interest in the investigation of the suitability of 3DP as an alternative strategy for the fabrication of SODFs is growing. Different 3DP technologies and starting materials have been investigated for the development of SODFs. Numerous SODFs with complex geometries and composition, and with different release patterns, have been successfully manufactured via 3DP. Despite that, just one 3DP SODF has reached the market.

SUMMARY

3DP can be a promising alternative to the classical SODFs manufacturing methods. However, numerous technically and regulatory challenges still need to be addressed in order 3DP to be extensively used in the pharmaceutical sector.

3D printing and enteric coating of a hollow capsular device with controlled drug release characteristics prepared using extruded Eudragit® filaments

This work focuses on the extrusion of a brittle, tacky, cationic copolymer i.e. Eudragit® E-100 to prepare filament and subsequent 3D printing of hollow capsular device using the extruded filament. An optimum amount of talc and triethyl citrate was used for the possible extrusion of the polymer. There was no thermal and chemical degradation of the polymer observed after extrusion confirmed by DSC and FTIR analysis. Microscopic analysis of the printed capsule showed the layer-by-layer manner of 3D printing. Capsule parts were printed according to the set dimensions (00 size) with minimal deviation. Printed capsule showed the soluble behaviour in gastric fluid pH 1.2 where within 15 min the encapsulated drug encounters with the dissolution medium and almost 70% drug was dissolved within 4 hr. In case of phosphate buffer pH 6.8, the printed capsule showed a longed swelling behaviour up to 12 hr and then gradually bursting of capsule occurred wherein more than 90% encapsulated drug was dissolved within 36 hr. Enteric coating of the printed capsule showed similar behaviour in alkaline medium that observed with non-enteric capsule. This indicates the potential application of this printed capsules for both gastric and intestinal specific delayed drug delivery by a single step enteric coating process.

Theoretical and experimental validation of praziquantel with different polymers for selection of an appropriate matrix for hot-melt extrusion

The selection of an appropriate matrix for the preparation of amorphous extrudate in hot-melt extrusion (HME) deals with the study of various solid-state properties of drugs and polymers. Therefore, it is necessary to have an appropriate knowledge of drug-polymer miscibility, the interaction between the drug-polymer on mixing, and Gibb's free thermal energy of mixing to screen polymers through thermodynamic phase diagrams, to be suitable amorphous matrix system for HME. Here, we evaluated the possibility of three different polymers, namely, Eudragit®EPO, polyvinyl alcohol (PVA), Kollicoat®IR (KIR) with Praziquantel (PZQ), with proper validation of the Flory-Huggins theory and construction of the phase diagram using the melting point depression approach to determine a suitable matrix for HME. The solubility parameter theoretical calculation approach was used as a preliminary study to validate the miscibility of PZQ with three different polymers. Theoretical and experimental validation studies using the Flory-Huggins interaction parameter value using the melting point depression approach and the effect of PZQ loading on the interaction parameter were systematically validated to predict thermodynamic phase diagrams and Gibbs free energy of mixing for screening these polymers for the preparation of amorphous extrudate. Using the phase diagram, the thermal processing temperature for the HME was determined using a T-φ phase diagram to obtain an appropriate matrix. The obtained extrudates were further validated through physical appearance, microscopic structure, thermal and functional group characterizations, followed by the PZQ assay. Thus, considering the solid-state properties, the processing parameters of HME were selected to obtain stable extrudates and an appropriate matrix for PZQ loading.

3D printed hollow microneedles array using stereolithography for efficient transdermal delivery of rifampicin

A 3D printed assembly of hollow microneedles (HMNs) array, conjoined with a reservoir void, was designed and additively manufactured using stereolithography (SLA) technology utilizing a proprietary class-I resin. The HMNs array was utilized for transdermal delivery of high molecular weight antibiotics, i.e., rifampicin (M_w 822.94 g/mol), which suffers from gastric chemical instability, low bioavailability, and severe hepatotoxicity. HMNs morphology was designed with sub-apical holes present in a quarter of the needle tip to improve its mechanical strength and integrity of the HMNs array. The HMNs array was characterized by optical microscopy and electron microscopy to ascertain the print quality and uniformity across the array. The system was also subjected to mechanical characterization for failure and penetration analyses. The ex vivo permeation and consequent transport of rifampicin across porcine skin were systematically evaluated. Finally, in vivo examinations of rifampicin administration through the microneedle reservoir system in SD rats revealed efficient penetration and desired bioavailability.