Search

Large batches of placebo and drug-loaded solid dosage forms were successfully fabricated using selective laser sintering (SLS) 3D printing in this study. The tablet batches were prepared using either copovidone (N-vinyl-2-pyrrolidone and vinyl acetate, PVP/VA) or polyvinyl alcohol (PVA) and activated carbon (AC) as radiation absorbent, which was added to improve the sintering of the polymer. The physical properties of the dosage forms were evaluated at different pigment concentrations (i.e., 0.5 and 1.0 wt%) and at different laser energy inputs. The mass, hardness, and friability of the tablets were found to be tunable and structures with greater mass and mechanical strength were obtained with increasing carbon concentration and energy input. Amorphization of the active pharmaceutical ingredient in the drug-loaded batches, containing 10 wt% naproxen and 1 wt% AC, was achieved in-situ during printing. Thus, amorphous solid dispersions were prepared in a single-step process and produced tablets with mass losses below 1 wt%. These findings show how the properties of dosage forms can be tuned by careful selection of the process parameters and the powder formulation. SLS 3D printing can therefore be considered to be an interesting and promising technique for the fabrication of personalized medicines.

Suboptimal treatment caused by inaccurate dosing of prescribed medications is a challenging issue for the pharmaceutical industry. As a result, certain groups of patients, especially pediatric patients, may suffer from a lack of specific dosage forms, leading to potential side effects. To address this issue, various manipulation techniques are being applied, such as tablet crushing, splitting, and solution preparations. Unfortunately, these methods lack accuracy and economic efficiency. 3D printing technology has been considered one of the potential solutions for manufacturing limited batch dosage forms. Dosage forms produced through 3D printing can be fabricated on demand for specific patients. Furthermore, the unique properties of these dosage forms, such as API amorphization, can be adjusted due to the high tunability of the 3D printing process. The work conducted in this thesis is dedicated to investigating the potential applications of Selective Laser Sintering (SLS) and the associated aspects of this method for manufacturing solid dosage forms. The investigations into printing parameters and formulation content enabled the establishment of correlations between these factors and the properties of the final dosage forms. Higher print temperature, Laser Power Ratio, and colorant concentration led to increased mass and hardness of the dosage forms. The polymer constitutes the major portion of the formulation in terms of mass. Consequently, various grades of polymer were examined to ascertain their chemical influence on the properties of the dosage forms. The findings revealed that the type of polymer, degree of hydrolysis, and dynamic viscosity of the polymer significantly impact both the dissolution rate and API amorphization. Utilizing FDM for printing the shell component of the drug delivery device improved its durability, whereas the SLS-printed insert resulted in a faster and adjustable dissolution rate. This experiment showcased the potential of combining th

The aim of this study is to investigate the influence of polymer chemistry on the properties of oral dosage forms produced using selective laser sintering (SLS). The dosage forms were printed using different grades of polyvinyl alcohol or copovidone in combination with indomethacin as the active pharmaceutical ingredient. The properties of the printed structures were assessed according to European Pharmacopoeia guidelines at different printing temperatures and laser scanning speeds in order to determine the suitable printing parameters. The results of the study indicate that the chemical properties of the polymers, such as dynamic viscosity, degree of hydrolyzation, and molecular weight, have significant impact on drug release and kinetics. Drug release rate and supersaturation can be modulated by selecting the appropriate polymer type. Furthermore, the physical properties of the dosage forms printed under the same settings are influenced by the selected polymer type, which determines the ideal manufacturing settings. This study demonstrates how the chemical properties of the polymer can determine the appropriate choice of manufacturing settings and the final properties of oral dosage forms produced using SLS.

The rising levels of greenhouse gas emissions from vehicular and industrial pollution constitute a serious concern not only for the environment but for our entire society. Traditional gas capture and separation techniques, such as amine scrubbing for CO2 gas separation, have been commonly used at a commercial scale, however issues relating to high costs and high energy requirements for sorbent regeneration have limited the efficiency of many of these techniques. The use of porous sorbents, such as metal-organic frameworks (MOFs), has garnered significant attention as an alternative method for the capture and separation of greenhouse gases in recent years, particularly due to their structural and functional tunability. Thus, part of this thesis explores the selective capture of CO2 and SF6 in five new MOFs and mixed-linker zeolitic imidazolate frameworks (ZIFs). The CO2 and SF6 adsorption in microporous bismuth-based MOFs containing narrow ultramicro-pores (e.g. UU-200) was not found to be correlated to the N2-accessible surface area of the framework but was related to pore size effects and possibly framework flexibility. Similar mechanisms for SF6 capture were observed in vanadium- and gallium-based MOFs (UU-201-4) in which an enhanced van der Waals interaction between the gas molecules and the pore surface was obtained due to the pore size of the materials coinciding with the kinetic diameter of SF6 (5.5 Å). This further resulted in good uptake capacities as well as SF6-over-N2 selectivites above 2.75 mmol g-1 and 43, respectively. Furthermore, the selective uptake of CO2 and SF6 could be modified in mixed-linker ZIF-7-8s by tuning of the pore aperture size through a controlled incorporation of the bulkier benzimidazolate linker in the frameworks. The removal of other environmental pollutants (e.g. phosphates) in porous materials such as amorphous mesoporous magnesium carbonate (MMC) was also investigated and showed that the material had superior sorption capacitie

Large batches of placebo and drug-loaded solid dosage forms were successfully fabricated using selective laser sintering (SLS) 3D printing. The tablet batches were prepared using pharmaceutical grade Plasdone S-360 (60:40 linear copolymer of N-vinyl-2-pyrrolidone and vinyl acetate) and activated carbon as the NIR-active pigment, which was added to improve the sintering of the polymer. The physical properties of the tablets were evaluated at different pigment concentrations (i.e. 0.5 and 1.0 wt.%) and at different laser energy inputs (LPR). The mass, hardness, and friability of the tablets were found to be tunable and structures of higher mass and mechanical strength were obtained with increasing carbon concentration and LPR. Amorphization of the active pharmaceutical ingredient in the drug-loaded batches, which contained 10 wt.% naproxen and 1 wt.% activated carbon, was achieved in-situ during printing and the obtained tablets showed friabilities below 1 wt.%. In conclusion, this study has shown that solid dosage forms of varying mass and mechanical strength can be manufactured using SLS 3D printing. The preparation of amorphous solid dispersions could further be prepared in a single step during the printing process thus making SLS 3D printing an interesting and promising technique for the fabrication of personalized medicines.