Natalja Genina

Ethylene vinyl acetate (EVA) as a new drug carrier for 3D printed medical drug delivery devices

The main purpose of this work was to investigate the printability of different grades of ethylene vinyl acetate (EVA) copolymers as new feedstock material for fused-deposition modeling (FDM™)-based 3D printing technology in fabrication of custom-made T-shaped intrauterine systems (IUS) and subcutaneous rods (SR). The goal was to select an EVA grade with optimal properties, namely vinyl acetate content, melting index, flexural modulus, for 3D printing of implantable prototypes with the drug incorporated within the entire matrix of the medical devices. Indomethacin was used as a model drug in this study. Out of the twelve tested grades of the EVA five were printable. One of them showed superior print quality and was further investigated by printing drug-loaded filaments, containing 5% and 15% indomethacin. The feedstock filaments were fabricated by hot-melt extrusion (HME) below the melting point of the drug substance and the IUS and SR were successfully printed at the temperature above the melting point of the drug. As a result, the drug substance in the printed prototypes showed to be at least partly amorphous, while the drug in the corresponding HME filaments was crystalline. This difference affected the drug release profiles from the filaments and printed prototype products: faster release from the prototypes over 30days in the in vitro tests. To conclude, this study indicates that certain grades of EVA were applicable feedstock material for 3D printing to produce drug-loaded implantable prototypes.

Three-Dimensional Printed PCL-Based Implantable Prototypes of Medical Devices for Controlled Drug Delivery

The goal of the present study was to fabricate drug-containing T-shaped prototypes of intrauterine system (IUS) with the drug incorporated within the entire backbone of the medical device using 3-dimensional (3D) printing technique, based on fused deposition modeling (FDM™). Indomethacin was used as a model drug to prepare drug-loaded poly(ε-caprolactone)-based filaments with 3 different drug contents, namely 5%, 15%, and 30%, by hot-melt extrusion. The filaments were further used to 3D print IUS. The results showed that the morphology and drug solid-state properties of the filaments and 3D prototypes were dependent on the amount of drug loading. The drug release profiles from the printed devices were faster than from the corresponding filaments due to a lower degree of the drug crystallinity in IUS in addition to the differences in the external/internal structure and geometry between the products. Diffusion of the drug from the polymer was the predominant mechanism of drug release, whereas poly(ε-caprolactone) biodegradation had a minor effect. This study shows that 3D printing is an applicable method in the production of drug-containing IUS and can open new ways in the fabrication of controlled release implantable devices.

Rapid interferometric imaging of printed drug laden multilayer structures

The developments in printing technologies allow fabrication of micron-size nano-layered delivery systems to personal specifications. In this study we fabricated layered polymer structures for drug-delivery into a microfluidic channel and aimed to interferometrically assure their topography and adherence to each other. We present a scanning white light interferometer (SWLI) method for quantitative assurance of the topography of the embedded structure. We determined rapidly in non-destructive manner the thickness and roughness of the structures and whether the printed layers containing polymers or/and active pharmaceutical ingredients (API) adhere to each other. This is crucial in order to have predetermined drug release profiles. We also demonstrate non-invasive measurement of a polymer structure in a microfluidic channel. It shown that traceable interferometric 3D microscopy is a viable technique for detailed structural quality assurance of layered drug-delivery systems. The approach can have impact and find use in a much broader setting within and outside life sciences.

Anti-tuberculosis drug combination for controlled oral delivery using 3D printed compartmental dosage forms: From drug product design to in vivo testing

&NA; The design and production of an oral dual‐compartmental dosage unit (dcDU) was examined in vitro and in vivo with the purpose of physically isolating and modulating the release profile of an anti‐tuberculosis drug combination. Rifampicin (RIF) and isoniazid (ISO) are first line combination drugs for treatment of tuberculosis (TB) that negatively interact with each other upon simultaneous release in acidic environment. The dcDUs were designed in silico by computer aided design (CAD) and fabricated in two steps; first three‐dimensional (3D) printing of the outer structure, followed by hot‐melt extrusion (HME) of the drug‐containing filaments. The structure of the fabricated dcDUs was visualized by scanning electron microscopy (SEM). The 3D printed compartmentalized shells were loaded with filaments containing active pharmaceutical ingredient (API) and selectively sealed to modulate drug dissolution. The drug release profile of the dcDUs was characterized by pH‐transfer dissolution in vitro and pharmacokinetics studies in rats, and resulted in modified release of the APIs from the dcDUs as compared to the free filaments. Furthermore, the selective physical sealing of the compartments resulted in an effective retardation of the in vitro API release. The findings of this study support the development of controllable‐by‐design dcDU systems for combination therapies to enable efficient therapeutic translation of oral dosage forms. Graphical abstract Figure. No caption available.

Application of a colorimetric technique in quality control for printed pediatric orodispersible drug delivery systems containing propranolol hydrochloride

The feasibility of a colorimetric technique was investigated in CIELAB color space as an analytical quality control method for content uniformity of printed orodispersible pediatric delivery systems. Inkjet printing was utilized to fabricate orodispersibe film formulations containing propranolol hydrochloride in a colored ink base using three different edible substrates. A thin sweetener coating layer of saccharin was successfully included in the final dosage forms for palatability purposes using a casting knife. Optical microscopy, scanning electron microscopy and scanning white light interferometry analyses were conducted to study the effect of printing on the surface morphology and topography of the substrates. Differential scanning calorimetry and attenuated total reflectance infrared spectroscopy were used to study the solid state properties and possible interactions between the drug and the excipients. The inkjet printing technique deposited precise and uniform escalating doses (0.08-3.16mg) of the active pharmaceutical ingredient onto the substrates (R(2)≥0.9934). A disintegration test with clear end-point detection confirmed that all the substrates meet the requirements of the Ph. Eur. to disintegrate within 180s. The colorimetric technique proved to be a reliable method to distinguish the small color differences between formulations containing an escalating dose of propranolol hydrochloride.

Social aspects in additive manufacturing of pharmaceutical products

ABSTRACT Introduction: Additive manufacturing (AM) techniques, such as drug printing, represent a new engineering approach that can implement the concept of personalized medicine via on-demand manufacturing of dosage forms with individually adjusted doses. Implementation of AM principles, such as pharmacoprinting, will challenge the entire drug distribution chain and affect the society at different levels. Areas covered: This work summarizes the concept of personalized medicine and gives an overview of possibilities for monitoring patients’ health. The most recent activities in the field of printing technologies for fabrication of dosage forms and ‘polypills’ with flexible doses and tailored release profiles are reviewed. Different scenarios for the drug distribution chain with the required adjustments in drug logistics, quality systems and environmental safety are discussed, as well as whether AM will be used for production of on-demand medicine. The impact of such changes in the distribution chain on regulation, healthcare professionals and patients are highlighted. Expert opinion: Drug manufacturing by traditional methods is well-established, but it lacks the possibility for on-demand personalized drug production. With the recent approval of the first printed medicine, society should be prepared for the changes that will follow the introduction of printed pharmaceuticals.

QR encoded smart oral dosage forms by inkjet printing

The use of inkjet printing (IJP) technology enables the flexible manufacturing of personalized medicine with the doses tailored for each patient. In this study we demonstrate, for the first time, the applicability of IJP in the production of edible dosage forms in the pattern of a quick response (QR) code. This printed pattern contains the drug itself and encoded information relevant to the patient and/or healthcare professionals. IJP of the active pharmaceutical ingredient (API)-containing ink in the pattern of QR code was performed onto a newly developed porous and flexible, but mechanically stable substrate with a good absorption capacity. The printing did not affect the mechanical properties of the substrate. The actual drug content of the printed dosage forms was in accordance with the encoded drug content. The QR encoded dosage forms had a good print definition without significant edge bleeding. They were readable by a smartphone even after storage in harsh conditions. This approach of efficient data incorporation and data storage combined with the use of smart devices can lead to safer and more patient-friendly drug products in the future.

Visualization and Non-Destructive Quantification of Inkjet-Printed Pharmaceuticals on Different Substrates Using Raman Spectroscopy and Raman Chemical Imaging

PurposeThe purpose of this study was to investigate the applicability of Raman spectroscopy for visualization and quantification of inkjet-printed pharmaceuticals.MethodsHaloperidol was used as a model active pharmaceutical ingredient (API), and a printable ink base containing lactic acid and ethanol was developed. Inkjet printing technology was used to apply haloperidol ink onto three different substrates. Custom-made inorganic compacts and dry foam, as well as marketed paracetamol tablets were used as the substrates.ResultsTherapeutic personalized doses were printed by using one to ten printing rounds on the substrates. The haloperidol content in the finished dosage forms were determined by high-performance liquid chromatography (HPLC). The distribution of the haloperidol on the dosage forms were visualized using Raman chemical imaging combined with principal components analysis (PCA). Raman spectroscopy combined with modeling by partial least squares (PLS) regression was used for establishment of a quantitative model of the haloperidol content in the printed dosage forms. A good prediction of the haloperidol content was achieved for the inorganic compacts, while a slightly poorer prediction was observed for the paracetamol tablets. It was not possible to quantify haloperidol on the dry foam due to the low and varying density of the substrate.ConclusionsRaman spectroscopy is a useful tool for visualization and quality control of inkjet printed personalized medicine.

Hot Melt Extrusion as Solvent-Free Technique for a Continuous Manufacturing of Drug-Loaded Mesoporous Silica

The aim of this study is to explore hot melt extrusion (HME) as a solvent-free drug loading technique for preparation of stable amorphous solid dispersions using mesoporous silica (PSi). Ibuprofen and carvedilol were used as poorly soluble active pharmaceutical ingredients (APIs). Due to the high friction of an API:PSi mixture below the loading limit of the API, it was necessary to add the polymer Soluplus® (SOL) in order to enable the extrusion process. As a result, the APIs were distributed between the PSi and SOL phase after HME. Due to its higher affinity to PSi, ibuprofen was mainly adsorbed into the PSi, whereas carvedilol was mainly found in the SOL phase. Intrinsic dissolution rate was highest for HME formulations, containing PSi, compared to pure crystalline (amorphous) APIs and HME formulations without PSi. HME is a feasible solvent-free drug loading technique for preparation of PSi-based amorphous solid dispersions.

Unintended consequences for patients of future personalized pharmacoprinting

Manufacturing pharmaceuticals by the use of 3D printing is a promising way to achieve more personalized drug treatment. To effectively use this technology, patients need to continuously measure their health, and new decisions have to be taken, for example, regarding the number of daily drugs including how many active pharmaceutical substances these should contain along with decisions around size, shape and color. Positive as well as negative effects of pharmacoprinted medicine on patients are likely to occur. Negative consequences with influence on patient autonomy and role might include: patients not being capable or interested in conducting self-monitoring, loosing overview of the medical treatment, reducing the ability to perform self-regulation, loosing trust in the pharmacoprinted medicine, and not being interested in taking on a new role in medical decision making. These issues are discussed in the paper in order to prevent upcoming challenges in the area of pharmacoprinting.