Powder Flow Properties Research Articles

Exploring effects of different pretreatments on drying kinetics, moisture diffusion, physico‐functional, and flow properties of banana flower powder

Banana flowers are highly susceptible to enzymatic browning. Different pretreatments are generally used to reduce enzymatic browning and also helpful to reduce the bitterness of banana flowers. This study explored different pretreatments effects on drying kinetics, moisture diffusion, physical, functional, flow, and sensory properties of banana flower powder. Samples were pretreated with five different pretreatments (T0: Control, T1: Blanching, T2: Citric acid solution, T3: Lemon juice, T4: Brine solution, T5: Rice rinse water) then dried under a tray dryer (50°C). Experimental data were fitted to thin-layer drying models and the Page model was found the best-fitted model for all pretreatments with the highest R2 values of 0.99652 (T0), 0.99584 (T1), 0.99438 (T2), 0.99499 (T3), 0.9950(T4), and 0.99903(T5). The diffusivity coefficient of moisture transfer was calculated by using Fick's second law and varied from 1.2925 × 10−6m2/s to 9.8493 × 10−7m2/s. Sample T5 showed the highest lightness L* of 56.66 ± 1.56 with redness (a*) of 2.31 ± 0.56, and yellowness (b) of 9.79 ± 0.42. The highest water solubility index was 35.8341 ± 0.35% (T0) and bulk and tapped density were varied from 0.3315 to 0.4023 g/cm3 and 0.4109 to 0.467 g/cm3. Pretreatments also affected flow, foaming, and oil binding properties. Industrial applications The finding of this study can be applied in the waste utilization process in banana farms and help to generate income for farmers. Pretreatment before processing can reduce enzymatic browning, bitterness, starchy flavor, and also helps to enhance functional, flow, color characteristic of banana flower powder which will increase consumer demand. This comparative study regarding pretreatment can be useful for different processing. The present work suggests that dipping banana flower slices in lemon juice and rice rinse water before drying operation valuable pretreatment technology for banana flower drying, which can not only improve color parameters of banana flower powder, but also enhance some functional and flow properties of banana flower powder. Data generated can be used for process design and new food product formulation. Novelty Impact Statement Drying of banana waste (flower) has been mathematically modeled. Effective diffusivity has been determined for understanding the physico-functional properties. Functional properties of banana flower powder are studied which is useful for new product development.

Effect of colloidal silicon dioxide and moisture on powder flow properties: Predicting in-process performance using image-based analysis

The effect of colloidal silicon dioxide (CSD) on powder flow properties of poor-flowing excipient lactose 200 M was investigated. Binary mixtures of different ratios of CSD as glidant were examined using a modern image-based flow measuring technique. Special attention was placed to subtle variations in powder flow from small changes in glidant concentration (0.025% w/w). Understanding the modes of interaction of particles and their effects on flowability using the method predicted the die filling performance during tablet manufacture. In addition, the importance of moisture content on powder flow properties was empirically underlined. A more efficient range of CSD was detected from 0.10 to 0.50% w/w in most of the tested conditions, which revealed a significant improvement in powder flow performance compared to higher amounts typically handled in the pharmaceutical industry.

Understanding flow properties of mannitol powder at a range of temperature and humidity

Inadequate flowability of powders in industries during handling can cause many problems. For example, lack of flow from hoppers, poor tablet weight consistency, and low production rate in tableting. Many factors are known to commonly affect flow properties of powders, such as temperature, humidity and conditioning duration. In this paper, flow properties of a mannitol powder, which was conditioned between 24 and 72 h at various high relative humidities and temperature, were measured using a shear tester. A statistical model was developed to investigate the relative importance of these variables on the mannitol flow properties. The developed model showed all independent variables are significant in estimating bulk cohesion. Two separate approaches were used to evaluate inter-particle forces in the bulk, and how these changed with environmental conditions. First, inter-particle forces were inferred from the measured bulk properties using the Rumpf model approach. Secondly, inter-particle forces were predicted based on a model of moisture present on the particle surface using a combination of Kelvin model with the Laplace-Young (KLY) equation. The second approach also involved a new method to measure surface energy of mannitol powder based on measurements using Finite Dilution Inverse Gas Chromatography (FD-IGC). The surface energies of the mannitol powder were measured at high temperature (35 °C) and at different range of relative humidities. In spite of the fundamentally different approaches to the two ways of inferring inter-particles forces, these forces came out within less than 1.5:1 in magnitude. The Rumpf approach from bulk behaviour data obviously reflected the measured change in behaviour with humidity in particular, but this was not predicted from the KLY approach, however the likely reasons for this are postulated and recommendations for improvement are made.

Starch Products as Candidate Excipients in a Continuous Direct Compression Line

Direct compression (DC) remains the most preferred technique to produce tablets, and its effectiveness is directly influenced by raw material attributes. Therefore, the selection of specific grades of excipients to achieve desirable powder flow and compression properties is of importance. Shifting toward continuous manufacturing requires even more enhanced performance, quality, and consistency directly from the starting ingredients. Starch, as a well-known excipient with good compression characteristics in its native state, is poorly flowing and highly sensitive to lubrication. The objective of this study was to characterize the flow properties of different starch products and investigate the suitability of modified starch products for continuous manufacturing. The proposed methodology included techniques to characterize material flow properties and their feeding performance in a loss-in-weight feeder. Principal component analysis (PCA) was then applied to project material properties onto reduced dimensions and compare the flow behavior of starch products with other common excipients. A newly developed starch product, StarTab®, was characterized and compared with two other starch products in terms of their flow behavior. StarTab showed desirable flowability and packing behavior, demonstrated by shear cell and compressibility results. During feeder refill studies, StarTab exhibited a low total deviation of material fed in excess of setpoint compared with the other two starch products. Additionally, it was observed that StarTab flow behavior was not sensitive to its moisture level. StarTab showed suitable characteristics compared with other starch products making it a potential candidate to design and develop pharmaceutical continuous direct compression (PCDC) formulations.

Development and evaluation of ketoprofen sustained delivery system using Neem Gum

Background: The main objective of this work is to formulate a sustained release matrix tablets using neem gum. Ketoprofen was selected as a model drug due to the low biological half life, it requires frequent administration. Hence sustained dosage forms are formulated to reduce the dosage frequency. Methods: Ketoprofen matrix tablets were formulated by employing neem gum as a release rate retardant material and used in 10%, 20%, 30%, and 40% Concentration levels. Wet granulation method was used to develop sustained release tablets. Results: Tablet was evaluated in terms of flow properties of blended powders and the average weight, drug content hardness, in vitro dissolution studies and fourier transformation-infrared spectroscopy (FT-IR) were determined. Drug release was evaluated with zero and the first order for release kinetics, Higuchi, Korsmeyer peppas models for the release mechanism. The hardness of the tablets ranged from 5 to 7 Kg/cm2 and the friability values were less than 1% indicating that the matrix tablets were compact and hard. All the formulations satisfied the content of the drug as they contained 99.1 to 100.8% of Ketoprofen, KNS3 released 99.2 of drug in 12 hours and KNS4 released 90.13% of drug in 12 hours using neem gum and This data reveals that drug release follows fickian diffusion mechanism Peppas model. Conclusion: The present study could establish the suitability of neem gum as Controlled released (CR) polymer in the design of matrix tablets.

Physicochemical, thermal, and flow properties of ice cream powder as influenced by moisture content

The physicochemical, thermal, and dynamic flow properties of ice cream powder were evaluated at different moisture contents. Particle size distribution increased and span decreased considerably as moisture increased. The adsorption isotherms were sigmoid-shaped and could be classified as Type II. Similarly, powder densities increased, while the angle of repose decreased. With increasing moisture content from 3% to 9%, the reduction in glass transition (Tg) from 50.29°C to 32.28°C and sticky point temperature (SPT) from 37.8°C to 14.3°C suggested that caking could occur easily. The basic flow energy and shear tests proved that ice cream powder would flow easily at 3% moisture content than at 9%. Compressibility and wall friction tests also corroborated the fact that ice cream powder was very cohesive at 9% moisture, manifesting difficulties in flow. It became evident that control of interactions of constituents with ambient relative humidity requires the management of storage conditions. Based on SPT, moisture sorption behavior, and dynamic flow properties, the recommended storage conditions for ice cream powder would be 25°C and less than 40% RH (should not exceed 60% RH during storage). Practical applications Powders are inherently complex as many factors influence their behavior during handling and storage. Moisture is the most important of them as it shapes the particle to particle interactions through the formation of strong capillary bridges and overall cohesiveness of the powder. Powders are thus dynamic systems, whose behavior drastically changes with minor modifications in moisture. In this study, the influence of moisture on physicochemical, thermal, and flow properties of ice cream powder was evaluated. The pragmatic approach for characterizing ice cream powder and its flow properties could be useful in understanding its behavior during handling, packaging, and storage. Also, the determination of moisture sorption behavior, glass transition, and sticky point temperatures would provide information on optimal storage conditions, shelf-life appraisal, and design of appropriate packaging.

Selective Laser Sintering 3-Dimensional Printing as a Single Step Process to Prepare Amorphous Solid Dispersion Dosage Forms for Improved Solubility and Dissolution Rate.

This study reports the development of ritonavir-copovidone amorphous solid dispersions (ASDs) and dosage forms thereof using selective laser sintering (SLS) 3-dimensional (3-D) printing in a single step, circumventing the post-processing steps required in common techniques employed to make ASDs. For this study, different drug loads of ritonavir with copovidone were processed at varying processing conditions to understand the impact, range, and correlation of these parameters for successful ASD formation. Further, ASDs characterized using conventional and advanced solid-state techniques including wide-angle X-ray scattering (WAXS), solid-state nuclear magnetic resonance (ssNMR), revealed the full conversion of the crystalline drug to its amorphous form as a function of laser-assisted selective fusion in a layer-by-layer manner. It was observed that an optimum combination of the powder flow properties, surface temperature, chamber temperature, laser speed, and hatch spacing was crucial for successful ASD formation, any deviations resulted in print failures or only partial amorphous conversion. Moreover, a 21-fold increase in solubility was demonstrated by the SLS 3-D printed tablets. The results confirmed that SLS 3-D printing can be used as a single-step platform for creating ASD-based pharmaceutical dosage forms with a solubility advantage.

Influence of sucrose reduction and starch type on bulk and powder properties of ready-to-use powdered dessert

The powdered food mixtures are widely consumed due to their ease of preparation and storage. Although the addition of sucrose improves the reconstitution process of ready-to-use powdered desserts, high amounts of sucrose are undesirable regarding the nutritional value. Therefore, present study aimed to determine the impact of the sucrose particle size and differences in starches on the powder flow properties of powdered puddings. The caking, powder speed dependency and cohesion tests along with the other bulk properties were grouped with the hierarchical cluster. A reverse relationship was found between the cohesion coefficient and cohesion index values. The cake was not formed in samples which comprised granulated sucrose and corn starch. However, the icing sugar containing puddings had considerably lower cake and mean cake strength values. Based on the results, the icing sugar can be regarded as a good ingredient for ready-to-use dessert considering the storage, handling and transportation conditions.

P.081 Developmental progression of interneuron network deficits in a 15q13.3 microdeletion mouse model – a glimpse on adolescent priming for schizophrenia?

Roller compaction is a continuous dry granulation process, where the powder is compressed between two counter-rotating rollers and compacted into ribbons. The quality and homogeneity of the granulate is determined by the uniformity and porosity of the ribbon, which depends on the feeding process of the primary powder to the rollers, the flow properties of the primary powder and process parameters such as roller forces. Previous work was conducted to improve the powder flow and distribution in the feeding zone by developing new feeding guiders, which are located in the feeding zone close to the rollers on the lab-scale roller compactor Alexanderwerk WP120 Pharma (Yu et al., 2018). These new feeding guiders were used to reduce the amount of powder that is delivered to the centre of the rollers and increase the amount of powder that is delivered to the sides of the rollers, in comparison to the original feeding guiders. This modified concept using new feeding guiders has been applied to the large-scale roller compactor Alexanderwerk WP200 Pharma in the present work. In order to evaluate the homogeneity of the ribbon properties across the ribbon width, the temperature profile and porosity distribution across the ribbon width were measured. The new feeding guiders resulted in ribbons being produced with a more uniform temperature profile and porosity distribution across the ribbon width when using the small and large scale roller compactors at different process parameters.

Simulation of flow properties of differently shaped particles using the discrete element method

AbstractMaterials in a powder form are frequently used in various industries for the manufacturing of commodity and high‐value products. To properly design the powder‐handling equipment and powder processes, it is essential to know the powder flow properties that depend, among other parameters, on the particle shape. The nonspherical particles such as aggregates, cylinders, corn‐shaped particles, and fibers are often used in the industry. Recently, modeling approaches have been devised to simulate the powder flow and particle−particle interactions in powder processing. In this article, we discuss an educational module developed to introduce students to the modeling of powder processes with particles of various shapes and techniques used for the measurement of powder flow properties. The module was designed to support the undergraduate and graduate courses for chemical, material, mechanical, and civil engineering students. The survey revealed that the module increased students’ theoretical knowledge of the powder processing and developed practical skills in the modeling of powder processes.

Drying of citrus grandis (pomelo) fruit juice using block freeze concentration and spray drying

Pomelo fruit juice is concentrated using two different techniques, i.e. block freeze concentration (BFC) and thermal concentration (TC), and both concentrates were spray dried separately to observe the effects of two different concentration techniques on the physicochemical properties of the spray dried powder. BFC juice had comparatively better values of retention of acidity, colour, vitamin C, DPPH● scavenging activity, total phenolic content (TPC), and total sugar content than TC juice. The powder obtained from the combination of BFC and spray drying had better retention of vitamin C (121.17 mg/100 g), colour, and exhibited higher DPPH● scavenging activity than TC spray dried powder. The physical parameters including solubility index, bulk density, and hygroscopicity were significantly higher in BFC spray dried powder. BFC was observed as an efficient concentration technique in comparison to TC as a pretreatment to produce spray dried powder with a better retention of bioactive components and powder flow properties.

Characterization of solid lipid dispersions prepared by hot fusion containing a double-fixed dose combination of artemether and lumefantrine

Objective The World Health Organization has called for the development of novel drug delivery systems to combat malaria – the fourth most prevalent cause of death globally. The plausibility of utilizing hot fusion to prepare solid lipid dispersions containing the prescribed first-line, double-fixed dose combination (artemether and lumefantrine), proposed for inclusion in directly compressed lipid matrix tablets, was investigated. Significance: Currently, no anti-malarial product is commercially available that employs lipid technology in a solid oral dosage form that contains this double-fixed dose combination. Through developing lipid matrix tablets, the stability, solubility and subsequent bioavailability of these drugs could be significantly enhanced in the presence of lipids or oils. Methods Hot fusion encompasses encompassed melt mixing of a selected lipid base and the dispersion of the active ingredient(s) therein below their glass transition temperatures. Solid-state characterization, particle size analysis and pharmacotechnical properties were evaluated, with particular focus given to powder flowability. Results Stearic acid in a 0.5:1 lipid:drug ratio demonstrated the best powder flow properties of the investigated solid lipid dispersion for inclusion into prospective lipid–matrix tablets duly based on an increase in overall particle size, a more spherical particle shape and improved powder flow properties compared to the individual active ingredients. Conclusion Good powder flow is critical for powders destined for inclusion into tablets – especially when employing direct compression as method of manufacture – in this case, lipid matrix tablets, which have demonstrated huge promise as a prospective dosage form for future use in malarial treatment.

EVALUATION OF FOAM-MAT DRYING BEHAVIOUR OF CRAB APPLE (MALUS FLORIBUNDA) FRUIT JUICE AND POWDER QUALITY

Malus floribunda (MF) is an ornamental plant and the fruits with its red flesh have potential to be used as natural food colorant. In this study, the effects of faba bean protein concentrate (FB) and maltodextrin (MD) levels on MF juice foam stability was evaluated. In addition, the effects of drying conditions (temperature/power) on drying kinetics and powder quality (powder flow properties, colour, and anthocyanin content) were determined. The foam stability was significantly dependent on the FB level (P <0.05), but MD addition didn’t have any significant effect (P >0.05). Drying period was reduced with foam-mat drying compared to control, and the average Carr index values were found between 17.3-26.0%, while the Hausner ratios were between 1.21-1.35. The redness and lightness values of foam-mat dried powders were comparably higher than the control and MD-added sample at every drying condition (P <0.05), although the anthocyanin content decreased with increasing drying temperatures.

Physicochemical Characterization of Grewia ferruginea Hochst. ex A. Rich Mucilage for Potential Use as a Pharmaceutical Excipient.

Gum and mucilages from natural sources are in recent times increasingly investigated for pharmaceutical applications. Different studies have shown that the gum and mucilage fraction of various species of the genus Grewia were found to be effective viscosity enhancers, stabilizers, disintegrants, suspending agents, gelling agents, bioadhesives, film coating agents, and binders. However, no study has been conducted on the potential use of Grewia ferruginea mucilage (GFM) as a pharmaceutical excipient. Therefore, this study was aimed at characterizing the Grewia ferruginea bark mucilage for its potential use as a pharmaceutical excipient. The mucilage was extracted from the Grewia ferruginea inner stem bark through aqueous extraction, precipitated with 96% ethanol, dried, and powdered. The powdered mucilage was characterized for different physicochemical properties such as powder property, loss on drying, solubility and swelling index, ash value, pH, viscosity, moisture sorption property, microbial load, and acute oral toxicity. According to the results, the percentage yield of the final dried and powdered GFM was found to be 11.96% (w/w). The density and density-related properties of the mucilage showed good powder flow property. The GFM exhibited pseudoplastic flow behavior. Moisture sorption property of GFM revealed its hygroscopic nature, and its solubility and swelling property was increased with temperature. The pH of GFM was near neutral. Microbial load of the mucilage was within the pharmacopoeial limit, and the oral acute toxicity test revealed that the mucilage is safe up to 2000 mg/kg. From the investigations of this study, it can be concluded that Grewia ferruginea bark mucilage has the potential to be utilized as an excipient in pharmaceutical formulations.

Flow properties of polymeric powders for selective laser sintering

The effect of temperature on the flow properties of three different polymeric powders was assessed in order to properly take into account real temperature conditions relevant to Selective Laser Sintering (SLS). Shear tests were carried out at temperatures from ambient conditions to values close to the melting temperature of the polymers. Tested flowability significantly worsens at temperatures 20–30 °C lower than the powder melting point. These results are consistent with the working temperatures identified by SLS machine users, but powder flow properties estimated at finite consolidation cannot be directly used to infer on powder spread-ability. Instead, when the average intensity of the interparticle forces is calculated from the powder flow properties, the derived granular Bond number correlates well with the most suitable process conditions experienced for these powders. In particular, Bond numbers lower than 100 are required for a satisfactory powder layer formation after spreading with the use of a blade.

Integrated Quality by Design Approach for Developing Nanolipidic Drug Delivery Systems of Olmesartan Medoxomil with Enhanced Antihypertensive Action.

Purpose: The present work endeavors to report a systematic approach of developing the lipidic self-nanoemulsifying formulation of olmesartan medoxomil (OMT) on the principles of Quality by Design (QbD). Methods: For preparing the self-nanoemulsifying formulation, a mixture of oil, surfactant and cosurfactant were used as vehicles. The excipients were selected after screening by solubility as well as pseudoternary phase titration studies. Mixture design was adopted for systematic optimization of the composition of nanolipidic formulations, which were evaluated for smaller globule size, stable zeta potential and lower values of polydispersity index. The optimized liquid self-nanoemulsifying formulation was identified using numerical and graphical optimization techniques, followed by validation of the experimental model. Solidification of self-nanoemulsifying formulation was carried out using porous carriers, and then optimized on the basis of oil adsorption potential, powder flow property and drug release performance. Pharmacokinetic study was performed in male Wistar rats for evaluating the drug absorption parameters. All the experimental data obtained were subjected to statistical analysis using oneway ANOVA followed by post hoc analysis using Student’s t test. Results: The optimized liquid self-nanoemulsifying formulation showed globule size <100 nm, emulsification efficiency <5 minutes andin vitro drug release >85% within in 30 minutes. Further, the solid SNEDDS formulation was effectively formulated using Neusilin US2 with maximum oil adsorption capacity and good micromeritic properties. Pharmacokinetic evaluation indicated 4 to 5-folds increase (P <0.05) in the values of Cmax, AUC, and reduction in Tmax from the nanoformulations vis-à-vis the marketed formulation. Conclusion: Overall, the developed nanolipidic formulation of olmesartan indicated superior efficacy in augmenting the drug dissolution and absorption performance.

Characterization of the Bulk Flow Properties of Industrial Powders from Shear Tests

Bulk flow properties from shear analysis of compacted powders can be evaluated following different approaches. Experimental values of shear stresses obtained by conventional shear cells are traditionally used to build yield loci, from which the most relevant flow properties could be found. Such flow properties play an important role in determining their performance under fluidization conditions. In this work, a useful app, named cYield, was developed by using the new Matlab’s App Developer environment. This tool enables users to calculate both linear (Coulomb) and non-linear (Warren–Spring) yield loci as the best fitting of the σ-τ experimental shear points. It also provides a wide range of statistical information related to the quality of the outcomes obtained. The different features of the tool are presented, and the crucial steps for the execution of its calculations are illustrated. Moreover, it has been applied for the yield loci analysis of four different materials traditionally used in manufacturing processes. The results confirm that the flow behavior of many industrial powders, especially if cohesive, is better described by a non-linear yield locus.

Evaluation of Process Conditions for Ultrasonic Spray Freeze Drying of Transglutaminase.

SUMMARYIn this study, a commercial transglutaminase enzyme was dried using an ultrasonic spray freeze drying method and the effects of the process conditions were optimized to maximize the final transglutaminase activity. Accordingly, process parameters affecting enzyme activity were selected, such as nozzle frequency (48 and 120 kHz), flow rate (2, 5 and 8 mL/min) and plate temperature for secondary drying (25, 35 and 45 °C). Moreover, the effects of different pH values (pH=2.0 and pH=9.0) and high temperature (80 °C) on enzyme activity, physical properties and particle morphology of transglutaminase were discussed. According to the results, transglutaminase preserved its activity despite ultrasonic spray freeze drying. Sonication enhanced the enzyme activity. Using the desirability function method, the optimum process conditions were determined to be flow rate 3.10 mL/min, plate temperature 45 °C and nozzle frequency 120 kHz. The predicted activity ratio was 1.17, and experimentally obtained ratio was 1.14±0.02. Furthermore, enzyme produced by ultrasonic spray freeze drying had low moisture values (2.92-4.36%) at 8 h of drying. When the morphological structure of the transglutaminase particles produced by ultrasonic spray freeze drying under the optimum conditions was examined, spherical particles with pores on their surfaces were observed. In addition, flow properties of the transglutaminase powders were considered as fair under most conditions according to the Carr index.

Preparation, Physicochemical Characterisation and DoE Optimisation of a Spray-Dried Dry Emulsion Platform for Delivery of a Poorly Soluble Drug, Simvastatin.

In the presented study, insight into the development and optimisation of the dry emulsion formulation and spray drying process is provided. The aim was to facilitate the dissolution of the poorly soluble, highly lipophilic drug, simvastatin, by forming spray-dried dry emulsion particles having adequate powder flow properties, while assuring sufficient drug content. Simvastatin and a mixture of caprylic, capric triglyceride and 1-oleoyl-rac-glycerol were employed as a model drug and solubilising oils, respectively. A matrix of the dry emulsions was composed at a fixed ratio mixture of mannitol and HPMC. Tween 20 was used in low amounts as the primary emulsion stabiliser. To facilitate process optimisation, a DoE surface response design was used to study the influence of formulation and process parameters on the particle size distribution, powder bulk properties, emulsion reconstitution ability, drug stability and process yield of spray-dried products. Two-fluid nozzle geometry was identified, studied and confirmed to be important for most product critical quality attributes. Models obtained after the study showed acceptable coefficients of determination and provided good insight in the relationship governing the process and product characteristics. Five model optimised products showed adequate process yield, suitable particle size distribution, good reconstitution ability and improved dissolution profile, when compared to a non-lipid-based tablet and the pure drug. However, the obtained dry emulsion powders exhibited poor flow character according to the Carr index. The optimised product was further analysed with NMR during lipolysis to gain insight into the species formed during digestion and the kinetics of their formation.

The Use of the Gas Nitriding Process for the Nitridation of Powder for Laser Powder Bed Fusion

AbstractAdditive manufacturing in the powder bed by means of laser powder bed fusion (L-PBF) combines the fast production of metallic components with complex geometrical structures with a high degree of customization and low raw material consumption. However, there is a high demand for the development of new alloys to achieve the desired properties of additively manufactured parts. Due to a lack of knowledge, only a small group of steel powders are currently available for L-PBF. As an example, Cr and CrMn steel powders with additional alloyed nitrogen could be used for L-PBF products for Ni-free medical devices. The present work investigates the possibility of alloying nitrogen to austenitic steel alloy powder and high alloyed martensitic steel powder via gas nitriding. For this purpose, an X30CrMo7-2 powder and an AISI 316L powder for additive manufacturing were arranged to form powder beds of different heights and nitrided at different temperatures, times and nitriding potentials. The nitrogen content was determined from the samples taken at different heights of the powder beds. Individual powder particles were examined by means of metallography, scanning electron microscopy and electron probe micro analysis. It is shown that the nitrogen concentration in the powder is essentially determined by the nitriding temperature. In the X30CrMo7-2 powder, nitride precipitation also occurs at high temperature and N and C gradients are present in the particles with an average nitrogen content of up to 4 mass%. In the 316L powder, a homogeneously distributed nitrogen content of 0.35 mass% can be achieved after gas nitriding at 420 °C for 24 h. The flow properties of both powders are hardly affected by gas nitriding.