Osmotic System Research Articles

Electrostatic powder coated osmotic pump tablets: Influence factors of coating powder adhesion and film formation

Electrostatic powder coating of osmotic pump tablets becomes increasingly attractive in pharmaceutical industry due to its dry coating process. The present study aimed to investigate the influence factors of electrostatic powder coating of osmotic pump tablets with ultrafine powders during the powder adhesion and film formation. The results of the powder adhesion evaluation indicated that the powder adhesion was significantly influenced by the liquid plasticizers and the charging voltage of the electrostatic spray gun. SEM and drug dissolution tests illustrated that coating particle size and curing time and temperature could significantly influenced the film formation process, a finer coating particle size and-/or higher curing temperature and-/or longer curing time led to a more continuous and uniform coating film. Those results indicate that a well-controlled coating film with high qualities could be fabricated by a well-designed electrostatic powder coating, suggesting it is a promising alternative for preparing osmotic drug delivery systems.

Simultaneous nitrification-denitrification using baffled osmotic membrane bioreactor-microfiltration hybrid system at different oxic-anoxic conditions for wastewater treatment

The efficacy of a baffled osmotic membrane bioreactor-microfiltration (OMBR-MF) hybrid system equipped with thin film forward osmosis membrane for wastewater treatment was evaluated at laboratory scale. The novel OMBR-MF hybrid system involved baffles, that separate oxic and anoxic zones in the aerobic reactor for simultaneous nitrification and denitrification (SND), and a bioreactor comprised of thin film composite-forward osmosis (TFC-FO) and polyether sulfone-microfiltration (PES-MF) membranes. The evaluation was conducted under four different oxic-anoxic cycle patterns. Changes in flux, salinity build-up, and microbial activity (e.g., extracellular polymeric substances (EPS) were assessed. Over the course of a 34 d test, the OMBR-MF hybrid system achieved high removal of total organic carbon (TOC) (86–92%), total nitrogen (TN) (63–76%), and PO4–P (57–63%). The oxic-anoxic cycle time of 0.5–1.5 h was identified to be the best operating condition. Incorporation of MF membrane effectively alleviated salinity build-up in the reactor, allowing stable system operation.

Metagenomic insights into the changes in microbial community and antimicrobial resistance genes associated with different salt content of red pepper (Capsicum annuum L.) sauce

Fermented red pepper (FRP) sauce has been eaten in worldwide for many years. The salt content and resident microbial community influences the quality of the FRP sauce and may confer health (e.g., probiotics) or harm (e.g., antibiotic resistance genes) to the consumers in some circumstances; however, the salt-mediated alteration of microbial community and antibiotic resistance genes are little known. In this study, a combination of whole genome sequencing and amplicon analysis was used to investigate the changes in microbial community and antimicrobial resistance genes in response to different salt content during red pepper fermentation. While the family Enterobacteriaceae dominated in high-salt (15–25%) samples, Lactobacillaceae quickly became the dominant population in place of Enterobacteriaceae after 24 days in 10% salt samples. Compared to 0.05 antibiotic resistance genes (ARGs) per cell number on average in 10% salt sample, 16.6 ARGs were present in high-salt samples, wherein the bacterial hosts were major assigned to Enterobacteriaceae including genera Enterobacter, Citrobacter, Escherichia, Salmonella and Klebsiella. Multidrug resistance genes were the predominant ARG type. Functional profiling showed that histidine kinase functions were of much higher abundance in high-salt samples and included several osmotic stress-related two-component systems that simultaneously encoded ARGs. These results give first metagenomic insights into the salt-mediated changes in microbial community composition and a broad view of associated antibiotic resistance genes in the process of food fermentation.

A model for extracellular freezing based on observations on Equisetum hyemale

In frost hardy plants, the lethal intracellular formation of ice crystals has to be prevented during frost periods. Besides the ability for supercooling and pre-frost dehydration of tissues, extracellular ice formation is another strategy to control ice development in tissues. During extracellular ice formation, partially large ice bodies accumulate in intercellular spaces, often at preferred sites which can also be expandable. In this contribution, the physico-chemical processes underlying the water movements towards the sites of extracellular ice formation are studied theoretically, based on observations on the frost hardy horsetail species Equisetum hyemale, with the overall aim to obtain a better understanding of the physical processes involved in extracellular ice formation. In E. hyemale, ice accumulates in the extensive internal canal system. The study focuses on the processes which are triggered in the cellular osmotic-mechanic system by falling, and especially subzero temperatures. It can be shown that when the temperature falls, (1) water flow out of cells is actuated and (2) “stiff-walled” cells lose less water than “soft-walled” cells. Furthermore, (3) cell water loss increases with increasing (= less negative) turgor loss point. These processes are not related to any specific activities of the cell but are solely a consequence of the structure of the cellular osmotic system. On this basis, a directed water flow can be initiated triggered by subzero temperatures. The suggested mechanism may be quite common in frost hardy species with extracellular ice formation.

Energy generation and storage by salinity gradient power: A model-based assessment

Abstract Three energy storage systems based on mixing and desalination of solutions with different salt concentrations are presented, namely, reverse electrodialysis, pressure retarded osmosis and capacitive Donnan potential, coupled to their corresponding desalination technologies: electrodialysis, reverse osmosis and membrane capacitive deionisation. Conceptual mathematical models are used to assess power densities and efficiency, and to address the influence on the performance of factors such as temperature and residence time. The maximum power densities for electrodialysis, osmotic and capacitive energy storage systems are calculated as 4.69, 4.83 and 0.503 W m−2, respectively, at 25 °C and residence time of 20 s, corresponding to an average fluid velocity of 5 mm/s. In order to achieve competitive economic energy (in the EU) with this power density, the membrane price needs to be lower than 2.9, 3.0 and 0.31$ m−2, for each of the technologies. Utilisation of waste heat to increase the temperature to 60 °C increases the power density to 8.54, 6.04 and 0.708 W m−2, which allows for 25% higher osmotic membrane price (3.7$ m−2), and over 80% and 40% higher price (5.2 and 0.43$ m−2) for the ionic exchange membrane used in the electrodialytic and capacitive energy storage system respectively, while still having economic energy production. Advantages and disadvantages of the proposed energy storage systems are discussed, along with the cost evaluation for each technology.

Practical applications of electroosmotic system using electrodes with conductive plastics and advanced osmotic pulse system

Practical applications of the two commonly used electroosmotic systems in Slovakia were monitored and described in the paper. Emerged problems were analysed, to test the relevance of the system used for moisture removal from the object. Own installation of electroosmotic system was done. Porous structure and salt content of treated masonry was analysed and the influence of advanced osmotic pulse technology on salts’ precipitation and moisture field homogenisation was tested. Best results were achieved using electrodes with conductive plastics and the power unit with pulse system.

Biosample Concentration Using Microscale Forward Osmosis with Electrochemical Monitoring.

We report the design and operation of an integrated microfluidics system that uses cellulose ester dialysis membranes coupled with disposable carbon and copper electrodes for monitoring and concentration of microliter scale biofluid samples. Dialysis membranes are typically used for buffer exchange, but in this work, membranes with 100-500 Da MWCO were evaluated for feasibility in concentrating small volume samples. This is an alternative to the use of centrifugation, ultrafiltration, and evaporative methods, where quantitative inline monitoring of sample concentration is challenging. The impact of draw solution used, osmotic concentration gradient, pH, and temperature were studied for the optimized concentration of bodily fluids. A system using sucrose in the draw solution generated the best results, with water removal rates of 0.023 mL min-1. PBS, urine, and saliva samples were concentrated up to 20-fold (PBS), 15-fold (urine), and 5-fold (saliva) in less than 3 h. The osmotic system further showed a 5-fold increase in the electrochemical signal for detecting pyocyanin, a biomarker for early diagnostics of the Pseudomonas aeruginosa pathogen in urine and saliva samples. Overall, the osmotic system can be easily integrated with point of care diagnostic systems for low cost improvement in signal amplification and limit of detection.

Osmotic drug delivery system: A review

Osmotic drug delivery uses the osmotic pressure level for controlled delivery of drugs by using osmogens. Osmotic systems for controlled drug-delivery applications are well established, both in human pharmaceuticals and in veterinary medicine. The process of osmosis is that can control the drug delivery system. Osmotic pressure created from external environment into the dosage form regulates the delivery of drug from osmotic device. Osmotic pumps are promising systems for controlled drug delivery. The systems are used for oral administration and implantation. Osmotic pumps consist of an inner core containing drug and coated with a semi permeable membrane. Keywords: Osmosis, Osmotic drug delivery system, Osmotic pump.

Osmotic drug delivery system of valsartan

The objective of this study is to design and evaluate a new EOP called swellable elementary osmotic pump (SEOP) of the freely water soluble drug, amitriptyline hydrochloride (1 g /mL) by adding water swellable polymers in the core. The hydrophilic polymers included in the core retard the highly water soluble drug by producing hydrogel within the core, which may restrict and delay the solvent contact with drug molecules and may increase the diffusional length of the solvent to achieve a constant release rate. Thus, this technology can be exploited to achieve constant drug release at predetermined rate especially for highly water soluble drugs.

An Improved Ecological Services Valuation Model in Land Use Project.

Natural ecosystems benefit human lives via providing fundamental life-support services and goods upon which human civilization depends. However, as nature provides those for free, many people believe that they are of little or no value and they exploit the land greedily and unreasonably, which makes serious ecological degradation. Concerning this issue, we present the ecological services valuation model (ESVM) to measure the cost of environmental degradation of land use cost, which is an evaluation model of environmental degradation cost. Environmental degradation cost refer to the cost of deterioration or compromise of natural environment through natural processes or human activities, which consists of opportunity cost and environmental damage cost. Land area is an important variable in the ESVM. Based on Osmotic system, we put forward the effective land area, which combines the scale factor and the impact of external environment. What is more, the Cobb–Douglas production function is modified to establish the model. Finally, we propose the calculation formula of the economic cost of land use projects. Analysis of effectiveness and sensitivity prove that ESVM was a relatively stable model.

Bacterial Sample Concentration and Culture Monitoring Using a PEG-Based Osmotic System with Inline Impedance and Voltammetry Measurements

Impedance measurements using graphite electrodes were used to detect the increase in culture medium conductivity due to bacteria growth in real time along with simultaneous voltammetric monitoring of pyocyanin concentration. Electrochemical methods were compared to conventional continuous monitoring of bacterial cultures using turbidity measurement at an optical density of 600 nm (OD600). A practical osmotic system was further designed for concentrating bacterial cultures during growth to enable earlier detection using the electrochemical methods. Bacterial cultures, starting from an initial culture density of 1 × 108 cells/mL, were grown inside a sealed cellulose ester dialysis membrane, while polyethylene glycol in LB medium was used as the draw solution outside the membrane to gradually concentrate the growing cultures. 0.7-mm-diameter graphite for mechanical pencils was utilized as working and counter electrodes with a platinum wire reference electrode for electrochemical measurements with and without the osmotic system. In the absence of forward osmosis, impedance measurements detected culture growth ~ 1 h faster than conventional OD600. Integrating osmosis showed a twofold decrease in the time to detect pyocyanin production as an indicator for bacterial growth. For impedance monitoring, removal of water by osmosis was conflated with the impedance decrease due to cell growth; however, the results show a promising ability to detect bacteria growth via an observed shift in osmotic impedance profile when bacteria are present in a sample. By monitoring the deviation in the impedance profile, a threefold improvement in detection time was achieved when compared to conventional OD600 measurements.

Development and performance assessment of a new integrated solar, wind, and osmotic power system for multigeneration, based on thermodynamic principles

This study analyzes a new renewable energy-based multigeneration system, in which the energy sources are efficiently utilized to generate several useful commodities such as hydrogen, oxygen, desalted water, and refrigeration along with electricity. Osmotic power from desalination brine solution is harvested to contribute to the electricity generation and to reduce the environmental impact of brine. The system units are concentrated photovoltaics/thermal (CPVT), wind turbines, thermal energy storage (TES), hydrogen electrolyzer, hydrogen fuel cell, multistage flash (MSF) distillation, vapor compression refrigeration (VCR) cycle, and pressure retarded osmosis (PRO). The energetic and exergetic performance of the overall system, as well as the system units, are calculated based on the first and second law of thermodynamics. Further, a comprehensive parametric study is conducted to investigate the effect of varying environmental and operational conditions, and the input parameters on the production rate, exergy destruction rate and efficiencies. For maintaining the high efficiency of CPV operation, the heat generated on photovoltaic (PV) cells is dissipated by an effective cooling system. This heat is then stored in the TES to be further utilized in desalination. The TES is used for eliminating energy fluctuations in the system and for a continuous operation by storing the energy for the time, when energy from the sun is not available. The electricity from CPV and wind power is used in the VCR cycle and hydrogen electrolysis. The fuel cell can be operated during the time of peak electricity demand. After performing thermodynamic analysis over the system, the overall energy and exergy efficiencies are determined as 73.3% and 30.6%, respectively. The exergy destruction rates of the components are specified. In brief, generation of multiple commodities is assured based on a clean operation by a novel integration of multiple clean energy sources in one system.

Long-term, continuous OsmoSampler results for interstitial waters from an active gas venting site at a shallow gas hydrate field, Umitaka Spur, eastern margin of the Japan Sea

Highly active gas venting and outcrops of gas hydrates were recently found at the Umitaka Spur, on the eastern margin of the Japan Sea, through seafloor observations using a remotely operated vehicle (ROV). This was followed by sampling by using conventional coring techniques. In this study, we deployed a long-term osmotic fluid sampling system (OsmoSampler) to record geochemical changes in the shallow sedimentary environment over time. The OsmoSampler collected interstitial water at 30 cm below seafloor (cmbsf), providing us with a continuous daily record of the concentrations of SO42−, Cl−, CH4, and C2H6 dissolved in interstitial waters over one year. General mean concentrations of SO42− and Cl− repeatedly showed synchronous increases and decreases over both long-term (i.e. dozens of days) and short-term (i.e. 3–5 days) periods. Such fluctuations relative to background seawater concentrations were likely caused by saline and fresh water generation due to gas hydrate formation and dissolution. The CH4 concentration was significantly higher (>1 mM) during large fluctuations in SO42− and Cl− over the first 3 months, which was attributable to gas-venting activity. This high venting activity of CH4 could have promoted the rapid, large-scale formation of gas hydrate. The CH4 concentration decreased gradually after the first 3 months, and was accompanied by a period of relatively low SO42− and Cl− concentrations due to the predominance of gas hydrate dissolution around the sampling site. In later months, the C2H6 concentration approached ∼1 μM and was accompanied by occasional, positive CH4 spikes, reflecting the release of trapped gases associated with the dissolution of hydrates. These processes are essentially controlled by the fluctuations in gas concentrations along the gas migration path, and are well-characterized by shallow interstitial water geochemistry.

Genomic Insights of Halophilic Planococcus maritimus SAMP MCC 3013 and Detail Investigation of Its Biosurfactant Production.

Moderate halophilic bacteria thrive in saline conditions and produce biosurfactant (BS) which facilitates the oil scavenging activity in the oil polluted surroundings. Production of such unusual bioactive molecules plays a vital role for their survival in an extreme and adverse environment. Current research deals with isolation of Planococcus maritimus strain SAMP MCC 3013 from Indian Arabian coastline sea water for BS production. The bacterium tolerated up to 2.7 M NaCl demonstrating osmotic stress bearable physiological systems. We used integrated approach to explore the genomic insight of the strain SAMP and displayed the presence of gene for BS biosynthesis. The genome analysis revealed this potential to be intrinsic to the strain. Preliminary screening techniques viz., surface tension (SFT), drop collapse (DC) and oil displacement (OD) showed SAMP MCC 3013 as a potent BS producer. BS reduced SFT of phosphate buffer saline (PBS) pH: 7.0 from 72 to 30 mN/m with a critical micelle concentration (CMC) value of 1.3 mg/mL. Subsequent investigation on chemical characterization, using thin layer chromatography (TLC), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H NMR and 13C NMR) and liquid chromatography mass spectrometry (LC-MS) revealed terpene containing BS having sugar, lipid moieties. The genomic sequence analysis of P. maritimus SAMP showed complete genes in the pathway for the synthesis of terpenoid. Probably terpenoid is the accountable backbone molecule for the BS production, but the later stages of terpenoid conversion to the BS could not be found. Moreover, it is important to highlight that till today; no single report documents the in-detailed physico-chemical characterization of BS from Planococcus sp. Based on genomic and functional properties, the term terpene containing BS is denoted for the surfactant produced by P. maritimus.

Sustained and controlled release of herbal medicines: The concept of synchronized release

Synchronized release, defined as simultaneous release of multiple components while keeping the inter-component ratios steady, is crucial to the design and development of sustained- or controlled-release delivery systems of herbal medicines. A theory of infinite dose dividing is proposed to interpret the rationale behind synchronized release. The key point of the mechanisms is to curb diffusion so as to offset the release divergence caused by differences in physicochemical properties of multiple components. In practice, pH-dependent gradient-release, erosion-controlled and osmotic pump delivery systems have been adapted to attain synchronized release of model herbal medicines. Nevertheless, synchronized release is still in the proof-of-concept stages and should be corroborated by more evidence with more model herbal medicines.

Development, Evaluation and Optimization of Osmotic Controlled Tablets of Aceclofenac for Rheumatoid Arthritis Management

Objective: Rheumatoid arthritis is a dreaded disease, characterized by pain, inflammation and stiffness of joints, leading to severe immobility problems. The disease shows circadian variation and usually gets aggravated in early morning hours. Aceclofenac, a BCS Class II compound is routinely used in the treatment of pain and inflammation associated with rheumatoid arthritis. The objective of this study was to develop an osmotic delivery system of Aceclofenac that after administration at bedtime would deliver the drug in the morning hours. </P><P> Methods: A series of osmotically controlled systems of aceclofenac was developed by using lactose, sodium chloride and hydroxypropyl methylcellulose K100M as osmogens. Cellulose acetate (2% w/v in acetone) with varying concentrations of polyethylene glycol-400 was used as the coating polymer to create semi permeable membrane and dissolution was carried out in 290 mOsm phosphate buffer. Formulation optimization was done from four considerations: cumulative release at the end of 6 hours (lag time), cumulative release at the end of 7 hours (burst time), steady state release rate and completeness of drug release. </P><P> Results: A formulation having swelling polymer hydroxypropyl methylcellulose in the core and lactose and sodium chloride as osmogens, polyethylene glycol-400 (16.39 %) as pore former, with a coating weight of 5% was a close fit to the target release profile and was chosen as the optimum formulation. Conclusion: Aceclofenac tablets containing lactose, HPMC and sodium chloride in the core, given a coating of cellulose acetate and PEG-400 (5% wt gain), generated a release profile for optimum management of rheumatoid arthritic pain.

Photosynthetic capacity, osmotic adjustment and antioxidant system in sugar beet (Beta vulgaris L.) in response to alkaline stress

Photosynthetic characteristics of sugar beet cultivars KWS0143 and Beta464 were studied under alkaline conditions, including 0 (A0, control), 25 (A1), 50 (A2), 75 (A3), and 100 mM of mixed alkali (Na2CO3:NaHCO3, 1:2). A2, A3, and A4 reduced net photosynthetic rate (PN), stomatal conductance, and transpiration rate, but rose intercellular CO2 concentration. Reduction in PN occurred probably due to nonstomatal limitation. The decrease in efficiency of photosynthetic electron transport might be the main reason for the decrease of PN. The concentrations of photosynthetic pigments were significantly reduced by high (A3 and A4) alkalinity. Changes in chloroplast ultrastructure are the reason for the decrease in chlorophyll content. Sugar beet could resist injury from alkali owing to osmotic substances and antioxidant enzymes if alkaline stress was at a lower level. The better performance of KWS0143 under alkalinity might be associated with its more efficient osmotic and antioxidant systems to resist injury of photosynthetic apparatus caused by alkalinity.

Characterization of crosslinked hard gelatin capsules for a structural assembly of elementary osmotic pump delivery system

The objective of this study was to characterize the crosslinked hard gelatin capsules (HGCs) for use as a structural assembly of elementary osmotic pumps (EOP). HGCs were crosslinked in formaldehyde vapor for 6, 12, and 24 h. Weight loss after immersing in various mediums, water soluble protein fraction, loss on drying, and formaldehyde residue were investigated. Fourier transform infrared (FTIR) spectra were used to detect the crosslinking formation. The EOP capsules were prepared for delivery of diltiazem hydrochloride (DIL HCl) and ambroxol hydrochloride (AMB HCl), which are freely and sparingly water soluble drugs, respectively. Physicochemical stability of storage crosslinked HGC shells was investigated. All crosslinked HGC shells were water insoluble. FTIR spectra exhibited intermediate lysine methylol and arginine methylol peaks. Storage time increased, moisture content increased and formaldehyde residue decreased. The developing EOP capsules were more appropriate for delivery of high water soluble rather than low water soluble drug. EOP capsule contained 100 mg DIL HCl using HGCs crosslinked for 12 h provided release profiles for 12 h with a lag time of 2.6–3.1 h. It was also found that DIL HCl EOP capsules prepared using crosslinked HGC shells stored for 90 days maintained the similar drug release profiles. AMB HCl EOP capsules exhibited low drug release. In summary, the crosslinked HGCs were applicable as a structural assembly of the osmotic controlled drug delivery system.

Increasing osmotic power and energy with maximum power point tracking

A feedback control system is developed for coordinated control of feed rates, draw rates, and loading on an osmotic power system. Carefully balancing these parameters in order to reduce the overall effect of various non-ideal phenomena has been previously discussed in the literature, however this is the first-ever system developed for automated, real-time, simultaneous control of all three of these operating parameters. The ability of the system to achieve maximum net power output is demonstrated for various commercial membranes, in response to fouling, and for both stand-alone pressure retarded osmosis as well as for combined reverse osmosis and pressure retarded osmosis application. Results provide insight into best operating conditions which can be helpful for rule of thumb design, and also clearly show that best conditions are case specific, and that osmotic energy conversion systems ultimately require feedback control for efficient performance especially in response to dynamic phenomena such as membrane fouling. The tradeoff between net power and energy is also demonstrated, and a maximum energy controller is also described.

Formulation and Comparative Evaluation of Etoricoxib Loaded Osmotic Drug Delivery Systems

Osmotic drug delivery systems are gaining interest as they deliver the drug based on the principle of osmosis. Osmosis is defined as the spontaneous movement of solvent from a solution of lower solute concentration to a solution of higher solute concentration through a semipermeable membrane Aim of this study was to formulate and evaluate oral osmotic drug delivery systems of Etoricoxib for the treatment of inflammation and arthritis. A single compartment system (tablet) and a multi-compartment system (capsule) have been prepared. The granules for the osmotic tablet were prepared by wet granulation technique using PVP K 30 in ethanol as binder. The granules were evaluated for its flow property and the tablets were compressed and coated. Then the osmotic capsules of Etoricoxib was prepared and coated. A micro orifice was drilled for the capsule. Both the tablets and capsules were evaluated and the best formulation was determined. The release studies showed that F1 formulation (osmotic tablet) which contained equal proportion of mannitol and lactose as osmogens showed a maximum release of 68.56% and was the most promising among the 6 formulations. The kinetic analysis was done for F1. The formulation was found to be stable at an accelerated temperature of 40° ± 2°C, RH 70 % ± 5 % for 45 days.