Chemical Engineering Commons^™

Physicochemical Characterization Of Safranal-Β-Cyclodextrin Inclusion Complexes Prepared By Supercritical Carbon Dioxide And Conventional Methods., Sanaz Abbaszadegan

Theses

Saffron (Crocus sativus. Linn) has attracted much attention over the last decade because it has a large number of potent and biologically active compounds such as crocin, crocetin, picrocrocin and safranal. Researchers have shown that safranal has high antioxidant and cytotoxicity activities against several types of tumour cells (e.g., hepatocellular carcinoma) both in-vitro and in-vivo. However, the low aqueous solubility of safranal prevents using it as a therapeutic or preventive agent.

β-cyclodextrin (β-CD) inclusion complexes are being used in pharmaceutical applications to alter physicochemical properties (e.g., solubility, volatility, stability, chemical reactivity, and bio-availability) of poorly water soluble drugs. Thus the …

Enzymatic Production Of Biodiesel From Fats Extracted From Lamb Meat Using Supercritical Co2, Hanifa Easa Taher

Theses

Due to the reduction in fossil fuel reserves and associated environmental impacts from using petroleum fuels, biodiesel has been presented as a feasible alternative because it is sustainable and environmentally friendly. In this study, it is proposed to investigate the feasibility of enzymatic production of biodiesel from waste animal fats using supercritical fluid technology for the extraction and reaction. The operating conditions that resulted in the optimum extraction and biodiesel production yield were identified. To the best of my knowledge of the investigators, the waste animal fat extracted by supercritical CO₂ (SC-CO₂) for the production of biodiesel …

Methane Partial Oxidation Over Phthalocyanine Catalyst, Yuan Zhu

Theses

The partial oxidation reaction of methane over a zeolite-supported ruthenium phthalocyanine catalyst is studied in a packed bed reactor. The investigation of such reaction is desirable because partial oxidation of methane yields a synthesis gas that can be upgraded to liquid chemicals and fuels.

Reactants of this study are He-diluted CH₄ and O₂. The effluent includes unreacted CH₄ and O₂, He, CO, CO₂, H₂, and H₂O vapor. Thermal conductivity gas chromatography is applied to identify the mole fractions of reactants and products. System pressure is maintained at 50 …

Production Of Stable Bcs Class Ii Drug Suspensions By Melt Emulsification And Subsequent Incorporation Into Polymer Strip Films, Emanuel Joseph Vizzotti

Theses

One of the ways to improve the dissolution rate of poorly water-soluble drugs is to produce fine drug particles with increased surface area. This increase will lead to bioavailability enhancement. However, smaller drug particles are thermodynamically unstable and tend to aggregate or grow. Therefore, proper formulation and process parameters must be chosen to keep the particles small. In this study, fine drug particles of two model drugs, fenofibrate and ibuprofen, are prepared by the melt emulsification technique. The influence of suspension formulation (i.e., the inclusion of polymers and surface-active agents) on particle stability is investigated. Moreover, different agitation techniques during …

Power Dissipation And Mixing Time In A Partially Filled Pharmaceutical Reactor Equipped With A Retreat-Blade Impeller At Different Fill Ratios, Aniruddha Banerjee

Theses

Glass-lined, stirred reactors and tanks are of significant industrial importance, especially in the pharmaceutical and fine chemical industries. These reactors are manufactured with a “glass-lining,” i.e., a glass layer applied to the agitator, the inside of the reactor/tank and to any of the surfaces in contact with its contents in order to maximize corrosion resistance, facilitate reactor cleaning, and minimize product contamination. Because of glass-lining fabrication issues, a retreat blade impeller with a low impeller clearance off the tank bottom is commonly used in glass-lined reactors. In addition, since wall baffles cannot be easily mounted on the wall of glass-lining …

Batch Foaming Of Hot Melt Extruded Excipient/Disintegrant/Api Pharmaceutical Formulations And The Study Of The Effects Of The Resulting Cellular Structures On Api Dissolution, Na Yao

Theses

This thesis focuses on the impact of a disintegrant included in a foamed immediate release system composed of a polymer excipient and an Active Pharmaceutical Ingredient (API). Indomethacin (INM) is used as model API; Eudragit® EPO (EPO) is used as polymer excipient; AcDiSol and Crospovidone (Cros) are used as two kinds of disintegrant. The main objectives are to gain an understanding of the resulting morphologies, as well as the impact of disintegrants on drug release from foamed polymeric matrices.

In the first part of this research, the Hot Melt Extrusion (HME) process is used to compound the following pharmaceutical formulations: …

Heterogeneous Combustion Of Condensed Particles In Transition Regime, Deniz Yildiz

Theses

A steady-state model of heterogeneous combustion for a spherical particle is developed accounting for the transition regime of heat and mass transfer. The model assumes formation of condensed products and reaction rate controlled by the transport of oxidizer to the particle surface. The model is based on the Fuchs’ limiting sphere approach. Calculations are performed for combustion of zirconium particles of different sizes. Temperature and oxygen concentration profiles are calculated and compared to those predicted by the continuous medium transfer model. It is shown that for particles in the range from 100 nm up to 30 gm heat and mass …

Effect Of Tablet Compression On The Dissolution Of Aspirin Tablets Using A Novel Off-Center Paddle Impeller (Opi) Dissolution Testing System, Chuan Sun

Theses

In the pharmaceutical industry, dissolution testing is routinely carried out to determine the dissolution rate of oral solid dosage forms. Among several testing devices, the USP Dissolution Apparatus 2 is the device most commonly used. However, despite its widespread use, this apparatus has been shown to produce test failures and to be very sensitive to a number of small geometry changes.

The objective of this study was to determine whether a novel dissolution system termed “OPI” for “off-center paddle impeller” was sensitive enough to determine differences in tablet dissolution profiles caused by different compression pressure during the tablet manufacturing process. …

Dissolution Of Different Commercial Aspirin Tablets Using A Novel Off-Center Paddle Impeller (Opi) Dissolution Testing System, Yang Qu

Theses

Dissolution testing is routinely conducted in the pharmaceutical industry to provide in vitro drug release information for quality control purposes. The most common dissolution testing system for solid dosage forms is the United States Pharmacopeia (USP) Dissolution Testing Apparatus 2. In this work, a modified Apparatus 2, termed "OPI" System for "off-center paddle impeller," in which the impeller is placed 8 mm off center in the vessel is tested to determine its sensitivity to differentiate between the dissolution profiles of differently formulated and manufactured tablets. Dissolution tests are conducted with both the OPI System and the Standard System using three …

Effects Of Api Particle Size On The Dissolution Rate In Molten Polymer Excipient Matrices During Hot Melt Extrusion, Conducted In A Co-Rotating Twin-Screw Extruder, Meng Li

Theses

The effect of the Active Pharmaceutical Ingredient (API) particle size on the dissolution rate in the polymer excipient during hot melt extrusion is investigated using a co-rotating twin-screw extruder with three different screw configurations. Acetaminophen (APAP) and amphiphilic polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (PVCap-PVAc-PEG) (Soluplus) are chosen as the model API and water- soluble polymer excipient, respectively. APAP is milled using a fluid energy mill (FEM) into two different particle sizes. The thermal properties of processed samples are characterized by TGA and DSC. SEM and optical microscopy are also used in the morphological studies. Under quiescent conditions, API particles …

Hollow Fiber Membrane-Based Air Gap Membrane Distillation, Xuan Wang

Theses

Membrane Distillation (MD) is a thermally-driven separation process. In this research, desalination of 1 % NaCl solution is achieved by one type of MD namely, Air Gap Membrane Distillation (AGMD). The characteristics of AGMD are evaluated by using a hollow-fiber-set-based compact device. Hot brine solution and cold water are passed through two different fiber sets separately: porous hydrophobic polyvinylidene fluoride hollow fibers of the E type (PVDF E) and solid polypropylene (PP) hollow fibers. Vapor from the hot brine crosses the membrane pores of the PVDF fibers and the air gap, and finally condenses over the surface of solid hollow …

Qsar Modeling Of Chemical Penetration Enhancers Using Novel Replacement Algorithms, Hui Qiu

Theses

The applications of transdermal delivery are limited because of the resistance of the skin to drug diffusion. Only potent drugs, with molecular weight less than 500 Da, are suitable to cross the skin barrier. Chemical Penetration Enhancers (CPEs) are used to promote the absorption of solutes across the dermal layers. In this investigation, a Quantitative Structure-Activity Relationship (QSAR) model is applied to relate chemical penetration enhancer structures with the flux enhancement ratio through a statistical approach.

A database, consisting of 61 non-polar CPEs, is selected for the study. Each compound is represented by 777 QSAR descriptors, which encode the physical …

Hydrodynamic Effects Of A Cannula In A Usp Dissolution Testing Apparatus 2, Qianqian Liu

Theses

Dissolution testing is routinely used in the pharmaceutical industry to provide in vitro drug release information for drug development and quality control purposes. The USP Testing Apparatus 2 is the most common dissolution testing system for solid dosage forms. Usually, sampling cannulas are used to take samples manually from the dissolution medium. However, the inserted cannula can alter the normal fluid flow within the vessel and produce different dissolution testing results.

The hydrodynamic effects introduced by a permanently inserted cannula in a USP Dissolution Testing Apparatus 2 were evaluated by two approaches. Firstly, the dissolution tests were conducted with two …

Engineering Spores To Display G Protein-Coupled Receptors For Directed Evolution, Alyssa Misoo Kim

Theses

All human cells are surrounded by a plasma membrane made from a phospholipid bilayer, which is responsible for maintaining a biologically active species, while stopping entry of deleterious substances from the outside. G protein-coupled receptors (GPCRs) are the membrane proteins, which transmit signals across the cell membrane. GPCRs are involved in almost every physiological process, and irregular control leads to pathological conditions. Therefore, they are major drug targets. Crystal structure determination is required to understand the molecular details of activation/deactivation. However, GPCRs are difficult to crystallize because of stability issues. An efficient protein engineering system needs to be developed. The …

Pvt Study Of Selected Uae Reservoir Fluids, Rashid Sher Mohammad

Theses

Phase behavior modeling in crude oil includes prediction of thermodynamic properties (such as saturation pressure, density, viscosity, thermal conductivity, etc.) for the vapor and liquid phases. The aim of phase behavior modeling is to establish the accuracy and reliability of the developed equation of state model to predict various other fluid phase behavior properties at high pressure and temperature conditions.

In the first part of this work, a new and reliable phase behavior apparatus designed in Brazil was used for the two-stage recombination process and phase behavior measurements. The recombination of the surface sample fluids (first-stage separator gas and stock-tank …

Optimization Of Co2 Wag Processes In A Selected Carbonate Reservoir: Laboratory Study, Mohamed Elwy Abdalla Amin

Theses

Miscible gas flooding using carbon dioxide is currently investigated as a possible EOR process for a number of United Arab Emirates (UAE) reservoirs. The major factors affecting the implementation of CO₂ floods are the availability of CO₂ at economic prices and the net utilization ratio of CO₂ per barrel of additional oil recovered.Minimizing net utilization requires controlling the high mobility ratio which causes lower sweep. To control the mobility ratio, the Water-Alternating CO₂-gas (WAG) technique is proposed.

The objective of this work is to experimentally assess the recovery of oil with CO₂ injection in …

Hydrodynamic Effects Of An Arch-Shaped Fiber Optic Probe In A Dissolution Testing Apparatus 2, Yiran Zhang

Theses

Dissolution testing is widely used in the pharmaceutical industry to evaluate newly developed drug formulations and as a quality control method to insure that solid dosage forms have consistent dissolution property. Typically, samples are manually drawn from the dissolution vessel prior to analysis. An approach to overcome the limitations of manual sampling consists in the use of sampling probes, such as fiber optic probes, permanently inserted in the dissolution medium and continually sampling the drug concentration in it as the solid dosage form dissolves. Despite their advantages, permanently inserted fiber optic probes can alter the normal fluid flow within the …

Supercritical Co2 Extraction Of Oil From Henna Flower: Experimental, Mathematical Modeling, And Antioxidant Activity, Bushra Saeed Mohammed Dohai

Theses

Henna is a plant that has been used traditionally for coloring nail, skin, and hair, and as medicinal plant. The supercritical fluid technology offers a considerable promise as extraction media due to its advantages over other conventional extraction techniques. The extraction of volatile components from flowers of henna was studied using supercritical carbon dioxide at temperatures and pressures ranging from 35 to 55°C and 80 to 120 bar, respectively. A maximum extraction yield of 31 % from 2g of henna flowers was obtained at 45 °C and 120 bar. The composition of the extracts was investigated by gas chromatography technique. …

Combustion Dynamics Of Individual Reactive Material Particles, Carlo Francisco Badiola

Theses

Metallic reactive powders are widely used as solid fuels, pyrotechnic materials, and components of enhanced blast explosives. Metals are attractive because of their high combustion enthalpies and temperatures. Quantitative descriptions of the combustion processes and mechanisms for both pure metal and composite particles are also desired for their proper implementation in specific applications. Among reactive metals, Al is used most widely and its combustion has been studied extensively. A recently developed experimental setup using laser-ignited metal powders enabled one to record optical signatures for time-resolved combustion instances for 2-25 µm diameter aluminum particles burning in different atmospheres. Individual particle diameters …

Preparation Of Different Polyamide Nanofiltration Membranes By Interfacial Polymerization And The Effect Of Post-Polymerization Treatment On Separation Performance, Yu Qin

Theses

Interfacial polymerization (IP) is a powerful technique for fabrication of thin film composite (TFC) membranes. In this study, polyamide nanofiltration (NF) composite membranes ware prepared by interfacial polymerization of polyethylenimine (PEI) or m-phenylene diamine (MPD) with isophthaloyl dichloride (IPD) on the surface of a porous polyethersulfone (PES) support. Concentrations of monomer reactants for this reaction were decided by equivalent weight ratio. A standard IP procedure was applied to successfully coat PES flat films. After preparation, three different post-polymerization treatments were employed and one optimal treatment was proven after membrane testing.

The TFC flat film membranes were characterized by nanofiltration of …

Dissolution Testing Of Prednisone And Salicylic Acid Calibrator Tablets At Different Tablet Locations, Anandhavalavan Arulmozhi

Theses

Dissolution testing is routinely carried out in the pharmaceutical industry to determine the rate of dissolution of solid dosage forms. This test is one of the several tests that pharmaceutical companies typically conduct on oral dosage formulations (e.g., tablets) to determine compliance. The USP Dissolution Testing Apparatus 2 is the most common of the apparatuses listed in the USP. However, it has been shown previously that the dissolution profile of a tablet undergoing dissolution in the USP Dissolution Apparatus 2 can be affected by the tablet location in the apparatus.

In this work, the dissolution rates of both non-disintegrating tablets …

Dissolution Of Disintegrating Solid Dosage Forms In A Modified Dissolution Testing Apparatus 2, Shrutiben Rameshbhai Parekh

Theses

Dissolution tests are routinely carried out in the pharmaceutical industry to determine the dissolution rate of solid dosage forms. Dissolution testing serves as a surrogate for drug bioavailability through in vitro–in vivo correlation (IVIVR), and it additionally helps in guiding the development of new formulations and in assessing lot-to-lot consistency, thus ensuring product quality. The United States Pharmacopoeia (USP) Dissolution Testing Apparatus 2 is the device most commonly used for this purpose. Despite its widespread use, dissolution testing using this apparatus remains susceptible to significant error and test failures. There is documented evidence that this apparatus is sensitive to several …

Transdermal And Transbuccal Delivery Of Lidocaine And Nicotine : Combined Effects Of Iontophoresis And Chemical Enhancers, Ran Wei

Theses

This study focused on the effects of iontophoresis and chemical enhancers on drug release. The transport of Lidocaine HCl (LHCl) and Nicotine Hydrogen Tartrate (NHT) through the skin and mucosa was evaluated for potential clinical applications. These two potential delivery routes have the advantage of avoiding first-pass effect. Samples were pretreated with enhancer solutions for one hour before the experiments. Passive or 0.3 mA iontophoresis-assisted drug diffusion was conducted for 8 hours to monitor the cumulative amount of drug released. Graphical methods and mathematical optimization techniques were implemented to analyze the data. The effects of chemical enhancers on the delivery …

Investigation Of The Potential Catalytic Activities Of Several Metal Organic Framework (Mof) Materials, Guangyu Zhang

Theses

Metal-organic frameworks (MOFs) are promising porous materials due to their high porosities, large apparent surface areas, tunable pore properties and selective uptake of small molecules. Many researches have been focused on developing new MOF structures and exploring their use in gas storage and separation. Only few studies investigated the catalytic properties of MOFs. In this study, catalytic properties are explored over several MOFs including zeolitic imidazolate framework-8 (ZIF-8), Ni(FA) and Zn(FA). These MOFs are used as catalyst supports for iron or platinum nanoparticles. The catalysts are prepared using incipient wetness impregnation method and characterized with Brunauer-Emmett-Teller (BET), pulse chemisorption, X-ray …

Thermochemical Properties, Bond Energies And Internal Rotor Potentials In Methyl Ethyl Sulfide And Oxygenated Sulfur Hydrocarbons Intermediates For Modeling Its Combustion And Atmospheric Chemistry, Guanghui Song

Theses

Small (1 to 4 carbon) hydrocarbon sulfides and thiols are formed in the biosphere by microorganisms and subsequently emitted into the lithosphere, hydrosphere and atmosphere. In the atmosphere they are oxidized by photochemical and radical reactions to intermediate hydrocarbon and to sulfur oxides. The oxides of these sulfur compounds and the intermediates from the oxidation process are known to form aerosols that can counteract the global warming green house effect. Recent studies also suggest that some aerosols can also contribute to global warming. Sulfur oxides are also major contributors to acid rain as the results of the atmospheric chemistry oxidation …

Study Of Controlled Release Of Dapsone From Modified Montmorillonite And Polymer Matrices, Jia Fan

Theses

This thesis focuses on the controlled release system of Dapsone (DAP) as the Active Pharmaceutical Ingredient (API) intercalated into sodium montmorillonite (MMT-Na+) and their combination with an anionic copolymer (Eudragit® S100). The effects of the excipients on the API dissolution rate were studied from their release profile in simulated intestinal fluid (pH=7.4) at 37±0.5°C. In the first part of the research, ionizable Dapsone was intercalated in the interlayers of MMT-Na+ to produce a nanohybrid. In the second part of the research, the nanohybrid was melt dispersed in the polymer to produce ternary (API/ Clay/ Polymer) composites. For comparison, API-polymer solid …

Recovery Of Carbon Dioxide From Flue Gases, Fahad Husain Al-Masabi

Theses

In this thesis, the modeling and simulation of the absorption of dilute CO₂ into falling film of aqueous solutions of a sterically hindered amine, 2-anino-2-methyl-1-propanol (AMP), was carried out using COMSOL Multiphysics Version 3.3. The operating cases were divided in two groups: (1) gas turbine operating cases (CO₂ 3 mol %) and (II) boiler operating cases (CO₂ 8.5 mol %). The key operating parameters for the studied cases are CO₂ partial pressure, operating temperature and amine concentration in the aqueous solution. The simulation focused on the following: (1) CO₂ Loading in aqueous AMP solution; (2) …

Design Of Drug Delivery Strategies Based On Well-Stirred Experiments, Kumud Kanneganti

Theses

Drugs are generally administered to the human body via injections (IV) or through other paths such as the buccal, nasal routes. The main consideration when designing a medication schedule is to maintain a therapeutic level of the drug in the body during the course of treatment. To achieve this goal, when IV drug therapy is selected, particular importance has to given to the dose to be injected and how to maintain the concentration of the pharmaceutical active ingredient (API) in the body between a Minimum Toxic Concentration (MTC) and a Minimum Effective Concentration (MEC). This therapeutic range varies with the …

Minimum Agitation Speed For Solid Suspension And Mixing Time In A Torispherical -Bottomed Pharmaceutical Stirred Tank Under Different Baffling Conditions, Dilanji Bhagya Wijayasekara

Theses

The minimum agitation speed, NS, required to just suspend solid particles dispersed in water was experimentally determined in this work for a glass-lined type of mixing tank provided with a torispherical bottom and agitated with a retreat-blade impeller under different baffling configurations. Ns for the same tank but equipped with a different agitation system, namely an axial impeller, was also experimentally determined for the purpose of comparing of performances of the two systems. The effect of impeller off- bottom clearance and the vessel's liquid level on the minimum agitation speed were also experimentally studied. Njs, was experimentally determined …

Enhanced Pervaporation Using A Novel Pump Configuration, Donough Patrick Shanahan

Theses

The pervaporation process is investigated in this work under the guises of process design improvements and process performance. Several avenues of research were investigated.

The main aim of the project was to investigate the use of liquid ring vacuum pumps for permeate recovery at laboratory and industrial scales. Due to technical and economical issues, these pumps were deemed unsuitable. This analysis then had to be extended further. Previous work investigated the use of dry vacuum pump systems on a lab scale and this work was extended to industrial scale simulations. Results from the lab scale process particularly those relating to …