Search Results (30)

We report a novel tablet-based reverse titration system for rapid, point-of-use measurement of water hardness, overcoming key limitations of conventional EDTA titration. Reagents are encapsulated in pullulan matrix giving two separate tablets. The first tablet contains the Eriochrome black T (EBT) and N-cyclohexyl-3-aminopropanesulfonic acid (CAPS) buffer, while the second encapsulates ethylenediaminetetraacetic acid (EDTA) disodium salt dihydrate. The system employs a trimodal detection strategy: qualitative screening via immediate color change with the EBT tablet, semi-quantitative estimation through combined tablet dissolution and adjusting the sample volume to a reference level, and quantitative determination using reverse titration, where water is gradually added until the red wine endpoint appears. This approach enhances interference tolerance from competing metal ions and improves accuracy over traditional methods. Testing with real water samples showed excellent agreement with standard titration. The tablets remain stable for over seven months, and the system eliminates the need for skilled personnel, laboratory equipment, or bulky instrumentation. This low-cost, user-friendly, and interference-tolerant platform enables rapid and accurate water hardness assessment at the point of use. Full article

Background/Objective: The high-shear granulator is considered an effective piece of equipment for layering pelletization because it enhances drug amorphization and improves drug dissolution. This study aimed to apply a high-shear granulator to prepare layered pellets containing a combination of hydrochlorothiazide and amlodipine besylate with improved physicochemical properties. Methods: Different molar ratios (2:1, 1:1, and 1:2) of the hydrochlorothiazide and amlodipine besylate mixture were deposited on the surface of the inert spheres of the microcrystalline cellulose (MCC) core by the mechanical effect of the high impeller speed. The resulting layered pellets were characterized using X-ray powder diffractometry (XRPD) and differential scanning calorimetry (DSC) to estimate the degree of the drug amorphization, and consequently a dissolution test was performed to determine the degree of the enhancement of the percentage of release. Additionally, micro-computed tomography (micro-CT) and a texture analyzer were used to determine the morphological characteristics and hardness of the resulting pellets, and then a stability study was performed. Results: On the basis of the micro-CT images, the MCC core was successfully loaded with a uniform layer of the drug combination at the pellet surface, which exhibited higher diameters than pure cellets. Furthermore, the drug combination in layered pellets was partially amorphized with a lower crystallinity percentage, a lower intensity, a broadening of the hydrochlorothiazide melting peak, and a higher cumulative release of both drugs with good stability, except pellets with a molar ratio of 1:2 that were recrystallized with a higher crystallinity percentage of 79.9%. Conclusions: Modifying the physical form and dissolution behavior of the hydrochlorothiazide and amlodipine besylate combination was achieved by single-step layering pelletization. Full article

Concentrated Solar Power (CSP) technology is advancing toward higher operating temperatures and lower costs: current systems operate at 565 °C, while next-generation systems are targeted to reach 800 °C to overcome efficiency limitations. In this context, low-cost, adaptable molten chloride salts have emerged as ideal heat transfer and thermal energy storage media. Metallic materials are susceptible to performance degradation under such conditions, which not only shortens equipment service life but also entails potential safety hazards. Thus, the development of alloy protection technologies resistant to molten salt corrosion has become an urgent priority for the deployment of next-generation CSP plants. Research has indicated that high-aluminum stainless steel is a promising candidate due to its unique advantages: it can form a stable Al₂O₃ protective film in oxygen-containing anionic environments, effectively inhibiting the dissolution of Cr, Fe, and other elements, and preventing the penetration of corrosive species. Additionally, the incorporation of magnesium-based corrosion inhibitors into MgCl₂-NaCl-KCl ternary molten salt systems has been proven to be an economically viable and efficient corrosion mitigation strategy. This study focused on high-aluminum 310S heat-resistant steel, with its performance validated through targeted experiments: samples subjected to pre-oxidation at 800 °C for 2 h were immersed in a specific ternary molten salt mixture (20.4 wt.% KCl, 55.1 wt.% MgCl₂, 24.5 wt.% NaCl) containing magnesium corrosion inhibitors, followed by a 600 h static corrosion test at 800 °C. The results revealed that the addition of magnesium significantly enhanced the corrosion resistance of high-aluminum 310S. These findings demonstrate that this material holds application potential in the storage tank and pipeline systems of next-generation CSP plants. Full article

Electrolytic plasma polishing technology is widely used in medical devices, aerospace, nuclear industry, marine engineering, and other equipment manufacturing fields, owing to its advantages of shape adaptability, high efficiency, good precision, environmental protection, and non-contact polishing. However, the lack of in-depth research on the material removal mechanism of the electrolytic plasma polishing process severely restricts the regulation of the process parameters and polishing effect, leading to optimization and improvement by experimental methods. Firstly, the formation mechanism of passivation film was revealed based on an analysis of the surface morphology and chemical composition of stainless steel. Subsequently, the dissolution mechanism of the passivation film was proposed by analyzing the change in the valence state of the main metal elements on the surface. In addition, the surface enclosure leveling mechanism of electrolytic plasma polishing (EPP) for stainless steel was proposed based on a material removal mechanism model combined with experimental test methods. The results show that EPP significantly reduces the surface roughness of stainless steel, with Ra being reduced from 0.445 µm to 0.070 µm. Metal elements on the anode surface undergo electrochemical oxidation reactions with reactive substances generated by the gas layer discharge, resulting in the formation of passivation layers of metal oxides and hydroxides. The passivation layer complexes with solvent molecules in the energetic plasma state of the gas layer with SO₄²⁻ ions, forming complexes that enter the electrolyte. The dynamic balance between the formation and dissolution of the passivation film is the key to achieving a flat surface. This study provides theoretical guidance and technical support for the EPP of stainless steel. Full article

Orodispersible thin film (ODF) is an innovative dosage form that allows for adjustable dosing and improved patient compliance. It is administered by mouth, where it dissolves, making it suitable for children. Objectives: The aim of the study was to develop and characterize an optimal ODF formulation containing equivalent hydrocortisone at 0.5 mg/cm² using the solvent-casting method. A stability-indicating assay for the simultaneous quantification of hydrocortisone and hydrocortisone 21-hemissucinate (HMS) was developed. ODFs were characterized by organoleptic properties and by testing for uniformity of mass, content, stability, thickness, and dissolution. Results: When optimized, ODF is thin, flexible, and transparent, making it suitable for production in hospital pharmacies using standard equipment. In contrast to the water-insoluble hydrocortisone, the HMS-loaded cast gel successfully satisfied the tests, including content uniformity. Disintegration appeared acceptable as compared to the commercial grade ondansetron ODF (Setofilm^®). The physicochemical stability of the active ingredients (i.e., HMS, hydrocortisone) contained in the ODF at 0.5 mg/cm² is demonstrated for at least 84 days at 23 °C. Conclusion: The ODF formulated with the water-soluble hydrocortisone prodrug HMS allows accurate drug level to be achieved, thus opening up new opportunities for use in pediatric patients. Full article

Dissolution of a poorly soluble active pharmacological substance in a drug carrier usually requires advanced techniques and production equipment. The use of novel carriers such as microemulsions, vesicles, or nanocarriers might entail various limitations concerning production cost, formulation stability, or active substance capacity. In this paper, we present a novel fumed silica-based organogel as a low-cost, simple preparation drug or cosmetic carrier with interesting rheological properties and high solubilization capacity. The objective of the study was to characterize the utility aspects of the new dermatological base with special emphasis on stability, rheology, and release studies. Various formulations of a silica organogel base with poorly soluble active pharmacological substances such as propolis or ibuprofen were prepared and tested. The studies of thermal stress, enforced syneresis, and long-term stability were performed along with analyses of rheological profiles of alkali-dependent sol–gel transformation and organogel release. The new drug vehicle shows high thermodynamic stability, thixotropic rheology and first-order release profile. Such properties are promising for commercial utility as a dermatologically applied base for poorly soluble substances. Full article

Numerous strategies have been developed for the corrosion protection of steel; however, most of them have a significant environmental impact and employ toxic compounds. Tannins are a green and promising solution for sustainable corrosion protection strategies. In this context, this work was focused on natural (condensed and hydrolysable) tannin layers as a possible corrosion protection strategy for carbon steel. The impact of the tannins’ dissolution medium (ultrapure water or Phosphate-Buffered Saline), surface pre-treatment (acid pickling or plasma), and deposition technology (dipping or spin coating) on layer homogeneity and adhesion has been evaluated. The effects of these parameters on coating formation, homogeneity, and adhesion have been investigated by means of visual inspections, swabbing, Fourier Transformed Infrared spectroscopy (FTIR), Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (SEM-EDS) and tape adhesion tests. Preliminary electrochemical corrosion tests have been performed on the most promising material (carbon steel acid pickled and coated with a hydrolysable tannin solved in water by spin coating) to estimate the protective ability of the developed layers and highlight the main criticisms to be overcome. Full article

A pediatric dosage form for crizotinib (Xalkori) was commercialized using quality-by-design principles in a material-sparing fashion. The dosage form consists of spherical multiparticulates (microspheres or pellets) that are coated and encapsulated in capsules for opening. The crizotinib (Xalkori)-coated pellet product is approved in the US for pediatric patients 1 year of age and older and young adults with relapsed or refractory, systemic anaplastic large cell lymphoma (ALCL) and unresectable, recurrent, or refractory inflammatory myofibroblastic tumor (IMT) that is ALK-positive. The product is also approved in the US for adult patients with non-small cell lung cancer (NSCLC) who are unable to swallow intact capsules. The lipid multiparticulate is composed of a lipid matrix, a dissolution enhancer, and an active pharmaceutical ingredient (API). The API, which remains crystalline, is embedded within the microsphere at a 60% drug loading in the uncoated lipid multiparticulate to enable dose flexibility. The melt spray congealing technique using a rotary atomizer is used to manufacture the lipid multiparticulate. Following melt spray congealing, a barrier coating is applied via fluid bed coating. Due to their particle size and content uniformity, this dosage form provides the dosing flexibility and swallowability needed for the pediatric population. The required pediatric dose is achieved by opening the capsules and combining doses of different encapsulated dose strengths, followed by administration of the multiparticulates directly to the mouth. The encapsulation process was optimized through equipment modifications and by using a design of experiments approach to understand the operating space. A limited number of development batches produced using commercial-scale equipment were leveraged to design, understand, and verify the manufacturing process space. The quality by design and material-sparing approach taken to design the melt spray congeal and encapsulation manufacturing processes resulted in a pediatric product with exceptional content uniformity (a 95% confidence and 99% probability of passing USP <905> content uniformity testing for future batches). Full article

At present, the methods for sulfur solubility testing of high-sulfur natural gas generally use laboratory proportioning gas samples and then connect equipment to test the sulfur solubility of the gas samples based on the adsorption deposition mechanism. However, these testing methods generally have the following problems: (1) The equipment used in these test methods has safety hazards such as leakage at pipe and valve connections. (2) The sulfur solubility of real gas samples cannot be measured directly. (3) The equipment is difficult to clean, and it is especially difficult to clean the sulfur deposited at pipe elbows and valve connections. This will lead to low sulfur solubility test results. (4) The thermal insulation performance during the test process is not good, and temperature changes have a great impact on gas volume measurement. In order to solve the above problems, a testing method and comprehensive experimental device for the solubility of elemental sulfur in high-sulfur natural gas were established. This test method wraps the entire experimental device with a metal shell, which has good safety and thermal insulation performance, and it uses customized pipeline connections, which have high flushing efficiency, less sulfur deposition, and more accurate experimental results. The upgraded filtration system can directly measure the sulfur dissolution of real gas samples, and a CS₂ solution recovery process is added to reduce the risk of leakage and environmental pollution. This method and equipment were used to test the elemental sulfur solubility determination of real gas samples from a high-sulfur gas well. The research results show that the solubility of elemental sulfur is related to temperature, pressure, and H₂S concentration and increases with the increase in temperature, pressure, and H₂S concentration. Compared with the previous method, this method has less residual sulfur during the test process, the measured sulfur solubility is 2.13% greater, and the test results are more accurate and reliable. This research result provides important basic data support for accurately measuring the elemental sulfur solubility of real gas samples in high-sulfur gas reservoirs and dealing with sulfur deposition problems. Full article

Background and Objectives: The enteric form of omeprazole is one of the most commonly prescribed medications. Similarly to Europe, Kazakhstan relies on the localization of pharmaceutical drug production as one of its primary strategies to ensure that its population has access to affordable and good-quality medicines. This study comprehensively describes the technologically available development of bioequivalent delayed-release omeprazole. Materials and Methods: Various regimes and technological parameters were tested on laboratory- and production-scale equipment to establish a technical process where a functional and gastro-protective layer is essential. According to the ICH guidance on stability testing and Kazakhstan local rules, stability studies were conducted under conditions appropriate for climate zone II. The comparison of the rate and extent of absorption with subsequent assessment of the bioequivalence of the generic and reference drugs after a single dose of each drug at a dose of 40 mg was performed. Results: The quantitative and qualitative composition and technology of producing a new generic enteric form of omeprazole in capsules were developed and implemented at the manufacturing site of solid forms. Dissolution profiles in media with pH 1.2 and 6.8 were proven. During the accelerated six-month and long-term twelve-month studies, the developed formulation in both packaging materials at each control point passed the average weight and mass uniformity test, dissolution test, acid-resistance stage test, buffer stage test, impurity assay, and microbiological purity test and met all the specification criteria. A bioequivalence study in 24 healthy volunteers compared against the innovative drug showed the bioequivalency of the new generic system. The obtained values from the test and reference products were 1321 ± 249.0 ng/mL and 1274 ± 233 ng/mL for C_max, 4521 ± 841 ng·h /mL and 4371 ± 695 ng·h /mL for AUC_0-t, and 4636 ± 814 ng·h /mL and 4502 ± 640 ng·h /mL for AUC_0-∞. Conclusions: Using affordable technologies, a bioequivalent generic delayed-release formulation of 20 and 40 mg omeprazole has been developed. Full article

As the field of personalized dosing develops, the pharmaceutical manufacturing industry needs to offer flexibility in terms of tailoring the drug release and strength to the individual patient’s needs. One of the promising tools which have such capacity is 3D printing technology. However, manufacturing small batches of drugs for each patient might lead to huge test burden, including the need to conduct bioequivalence trials of formulations to support the change of equipment or strength. In this paper we demonstrate how to use 3D printing in conjunction with virtual bioequivalence trials based on physiologically based pharmacokinetic (PBPK) modeling. For this purpose, we developed 3D printed ropinirole formulations and tested their bioequivalence with the reference product Polpix. The Simcyp simulator and previously developed ropinirole PBPK model were used for the clinical trial simulations. The Weibull-fitted dissolution profiles of test and reference formulations were used as inputs for the model. The virtual bioequivalence trials were run using parallel design. The study power of 80% was reached using 125 individuals. The study demonstrated how to use PBPK modeling in conjunction with 3D printing to test the virtual bioequivalence of newly developed formulations. This virtual experiment demonstrated the bioequivalence of one of the newly developed formulations with a reference product available on a market. Full article

Orally disintegrating granules (ODGs) are a pharmaceutical form commonly used for the administration of NSAIDs because of their easy assumption and fast dispersion. The development of ODGs is not easy for drugs like dexketoprofen trometamol (DXKT), which have a bitter and burning taste. In this work, high-shear coating (HSC) was used as an innovative technique for DKXT taste masking. This study focused on coating DXKT granules using the HSC technique with a low-melting lipid excipient, glyceryl distearate (GDS). The HSC technique allowed for the coating to be developed through the thermal rise resulting from the friction generated by the granules movement inside the equipment, causing the coating excipient to soften. The design of the experiment was used to find the best experimental coating conditions in order to gain effective taste masking by suitably reducing the amount of drug released in the oral cavity. The influence of the granule dimensions was also investigated. Coating effectiveness was evaluated using a simulated saliva dissolution test. It was found that low impeller speed (300 rpm) and a 20% coating excipient were effective in suitably reducing the drug dissolution rate and then in taste masking. The coated granules were characterized for their morphology and solid-state properties by SEM, BET, XRPD, DSC, and NIR analyses. A human taste panel test confirmed the masking of DXKT taste in the selected batch granules. Full article

Natural gas injection is considered for enhanced oil recovery (EOR) in a high saturation pressure reservoir in block B111 of the Dagang oilfield, China. To investigate the interaction characteristics of injected natural gas and crude oil, the ability for dissolution–diffusion and miscibility–extraction of natural gas in crude oil was tested using a piece of high-temperature and high-pressure PVT equipment. The physical properties and minimum miscible pressure (MMP) of the natural gas–crude oil system and their interaction during dynamic displacement were analyzed using the reservoir numerical simulation method. The results show the following: (1) Under static gas–oil contact conditions, natural gas has a significant dissolution–diffusion and miscibility–extraction effect on the crude oil in block B111, especially near the gas–oil interface. The content of condensate oil in gas phase is 10.14–18.53 wt%, while the content of dissolved gas in oil phase reaches 26.17–57.73 wt%; (2) Under the reservoir’s conditions, the saturated solubility of natural gas injected in crude oil is relatively small. The effect of swelling and viscosity reduction on crude oil is limited. As the pressure increases with more natural gas dissolved in crude oil, the phase state of crude oil can change from liquid to gas; accordingly, the density and viscosity of crude oil will be greatly reduced, presenting the characteristics of condensate gas; (3) The MMP of natural gas and crude oil is estimated to be larger than 40 MPa. It mainly forms a forward-contact evaporative gas drive in block B111. The miscible state depends on the maintenance level of formation pressure. The injected natural gas has a significant extraction effect on the medium and light components of crude oil. The content of C2–C15 in the gas phase at the gas drive front, as well as the content of CH₄ and C16+ in the residual oil at the gas drive trailing edge, will increase markedly. Accordingly, the residual oil density and viscosity will also increase. These results have certain guiding significance for understanding gas flooding mechanisms and designing gas injection in block B111. Full article

Tantalum and its alloys are regarded as equipment construction materials for processing aggressive acidic media due to their excellent properties. In this study, the influence of severe rolling (90%) on the dissolution rate of a cold-rolled Ta-4%W sheet in different directions was investigated during immersion testing and the corresponding mechanism was discussed. The results show that the dissolution rate of the cold-rolled sample is significantly lower than that of the undeformed sample. The corrosion resistance followed the sequence of “initial” < “90%-ND” < “90%-RD” < “90%-TD”, while the strength is in positive correlation with the corrosion resistance. Severe rolling promotes grain subdivision accompanied by long geometrically necessary boundaries and short incidental dislocation boundaries on two scales in the cold-rolled sample. The volume elements enclosed by geometrically necessary boundaries form preferential crystallographic orientations. Such preferential crystallographic orientations can greatly weaken the electrochemical process caused by adjacent volume elements, resulting in greatly reduced corrosion rates in the severely deformed sample. The unexpected finding provides a new idea for tailoring the structures of tantalum alloys to improve both their strength and corrosion resistance. Full article

The latest continuous flow micro reaction technology was adopted to independently develop carbonate rock dissolution test equipment. Carbonate rock dissolution tests were conducted under different temperatures, flow rates, and dynamic water pressure conditions to study the dissolution process of carbonate rocks under the coupling of heat-water-chemistry. The dissolution effect and development law of carbonate rocks were explored by quantitatively studying carbonate rock dissolution rate and chemical composition of karst water. The results showed that the self-designed dissolution test equipment has obvious advantages. After dissolution, carbonate rock specimens were damaged to varying degrees. The dissolution rate was proportional to water velocity and hydrodynamic pressure, with the velocity effect being greater than the hydrodynamic pressure effect. The pH value, conductivity, and Ca²⁺ ion content of the reaction solution gradually increased after dissolution. The development and application of the equipment have proved that, at low dynamic water pressures (2 MPa), the water flow velocity effect on the dissolution velocity was 1.5 times that when the dynamic water pressure was high (6 MPa); at a low water flow velocity of 15 mL/min, the dynamic water pressure effect on the dissolution velocity was three times that when the water flow velocity was high (75 mL/min). The development process is gradually becoming strong and stable. Its research has important theoretical significance and engineering application value to provide technical means and guarantee for the early identification, karst development, and safety evaluation of karst geological disasters. Full article