Some Properties of an Ethoxylated Castor Oil and Ethoxylated Oleyl Alcohol

Abstract

Ethoxylated derivates have been used as surfactants for some years. In this work, ethoxylated castor oil and ethoxylated oleyl alcohol alone and/or their I:I mixtures were used as surfactants in oil/water type of emulsion systems.

The physicochemical properties of ethoxylated castor oil (Simulsol OL 50) and ethoxylated oleyl alcohol (Simulsol 98) have been investigated.

Both of these materials have properties associated with non-ionic surfactants, although considerably soluble in water, the compounds have slight solubility in nonpolar solvents.

Surface tensions of aqueous solutions were measured over a temperature range of 20°C to 40°C. CMC were determined by surface tension measurements. pH, refractive index, conductivity and density of the two surfactants were also determined.     

Polymorphism of Fostedil: Chracterization and Polymophic Change by Mechanical Treatments

Two crystal forms of fostedil were characterized using X-ray diffraction patterns and infrared spectra. The melting points of polymorph I and II were 95.3 °C and 96.4 °C, respectively.

Solubility studies demonstrated that, of the two fostedil polymorphs, form II was slightly more soluble than form I. The free energy difference between two polymorphs was small (71.8 cal/mol at 37 °C). Both crystals melted at about 60 °C in water considerably below the melting points.

Compression of form II at a compression force of 500 - 1000 kg/cm² induced polymorphic changes in the crystal. Similar changes also were produced through grinding. The effects of some diluents on the polymorphic transformation from form II into form I by grinding were also studied. Microcrystalline cellulose and corn starch showed a polymorphic transfomation-accelerating effects.

Form I is more suitable for the pharmaceutical preparation.     

A Stability Study of Clindamycin Hydrochloride and Phosphate Salts in Topical Formulations

The stability of clindamycin hydrochloride and clindamycin phosphate was studied in topical liquid formulations prepared with the following solvents: solvent A (70% isopropanol, 10% propylene plycol and 20% water), solvent B (48% isopropanol, polyoxyethelene ethers, acetone, salicylic acid and allantoin), solvent C (40% alcohol, acetone, polysorbate 20, fragrance and water) and “standard” (50% isopropyl alcohol, propylene glycol and water) in glass and plastic containers at 25°, 40°, and 50°C.

It was found that, in general, better stability was obtained in glass containers than in plastic containers. At 25°C both the clindamycin hydrochloride and phosphate formulations in solvent B showed poorer stability than in the other solvents irrespective of the type of container, while formulations in solvent C showed the best stability. In addition, the effect of the pH on the stability of the formulations was determined, and it was clear that at pH values below 4 the stability of all formulations decreased.     

Medicament Release from Suppository Bases: II. Naproxen Physicochemical Characteristics and Bioavailability in Rabbits

Suppositories containing 25mg naproxen were prepared by the fusion method with tehobroma oil, PEG 1000, and witepsol 11-15. The liguefaction point and the time for complete liquefaction at temperatures from 37°C to 47°C were determined. By utilizing the SBT (Erwka) apparatus it was determined that the witepsol 11-15 formed supposltories which were more brittle.

The In vitro release rates were determined by using the USP method and by a modified one with dialyzing cellophane tubing. Samples withdrawn at definite time interval for up to 6 hours, and were analyzed by the spectrofluorometric method. The in vivo drug release was studied in rabbits. Ten blood samples were collected over a 24 hour period following administration of a 25mg dose of each suppository and of oral suspension. Plasma samples were assayed by spectrofluorometric method. A student “t” test was conducted on all date from the four different formulations and indicated significant difference between theobroma oil and oral suspension.

Significant correlation was obtained between the in vivo absorption and in vitro release when the suppository was placed In a dialyzing cellophane membrane.     

Phase Transformations in Sulfathiazole During Mechanical Activation

The effect of mechanical treatment in a planetary ball mill on the transformations of polymorphs of sulfathiazole were studied by means of X-ray diffraction analysis, infrared spectroscopy and differential scanning calorimetry. It has been shown that mechanical treatment initiates transitions of sulfathiazole polymorphs III ⇆ I. In an initial period of mechanical treatment a part of the sulfathiazole was converted into a noncrystalline solid. Preliminary mechanical treatment of form III resulted in the reduction of III—I phase transition temperature by 20-30°C in the samples without form I and by 40-50°C in the samples where the part of the substance were transformed into form I during mechanical treatment.

Single crystal thermomicroscopy studies showed that III → I phase transition proceeds via nucleation and a rapid advance of an interface through the crystal.

It seems that deformation of crystals during mechanical treatment and formation of noncrystallirie solid with high extent of disordering make probable the initiation of phase transition of sulfathiazole during mechanical treatment.     

ULTRA-PRECISION DIAMOND MACHINING OF ADVANCED TECHNOLOGY COMPONENTS

The design, development, and application of ultra-precision CNC machines for

the single point diamond turning of non-conventional metal optical components (Al, Ge, etc. )

the diamond grinding of ferrite and, other ceramic components for magnetic disc flying heads, etc.

is described. In both cases, tolerances on workpieces in the order of ± 0·1 μm were specified and achieved, together with the overriding need to minimize degenerated surface layers, i.e. surface damage.

The effects of chip formation at low depths of cut are discussed. The factors affecting the depths of “damaged layers” formed in turning and grinding are mentioned. Typical advanced technology components for which ultra-precision diamond turning or grinding are widely used are:

Convex mirrors for high output C0₂ laser resonators

X-ray mirrors

infrared lenses in germanium for thermal imaging systems

scanners for laser printers. and drums for copiers

elliptical mirrors for YAG laser beam collectors

spherical bearing surfaces in beryllium, copper, and other materials

ceramics for magnetic read/write heads for computer memory discs

ceramics for cams, cam followers, valve seat inserts, cylinder liners, bearings, cylinder heads, turbo impell ers, etc.

Both single point and diamond grinding for ultraprecision low stress surfaces demand high precision machines that provide

high stiffness of structures and high band-width servo drives;

low rumble, high averaging bearings such as hydrostatic air or oil;

high internal damping of stuctures and drive systems;

multi closed loop control of many parameters, including temperature of coolant and temperature gradients across structures and sub-systems;

coolant delivery to the abrasive/workpiece interface is of critical importance for controlling high surface finish and minimizing surface tresses.

The paper gives examples of how these problems are satisfied in today's state of the art ultra-precision CNC machine tools.     

Solubility Studia of Certain 2.3 Quinolino - Phthalidea

The solubilities of feve derivatives of 2.3 quinolino-phthalides in distilled water and in potassiem chloride solatioas of varying ionic atrength was detarained at 25°. 37°. and 51°C. The solubilities were lower in potassium chloride solutions: the over-all “aslting- out” comfficients were caleulated. for the effects of potaasium chloride using the empirical Setschenow equation logSo/S=KC

The differential beats of aolutions ranged from 2kcal/mole to 7.5 kcal/wole and were determined from the slopers of the semi-logaritimumic plots. of the solubilitiea verus the reciprocal temperaturas. The affect of the functional groups on this water solubilities of these compounds will be dlscussed.     

Solubility of Various Sulfonamides in N-Alkanols I. Effect of Polarity and Temperature

The solubilities of several sulfonamides were studied at three temperatures over a wide spectrum of polarity of normal alcohols. The sulfonamides chosen for study were sulfasoxaeole, sulfadimethoxine, sulfasomidine and sulfadiazine and their solubility behavior in various alcohols such ae methanol through 1-decanol at 25°. 30° and 37°.

Solubility in alcohols was found to increase with temperature and the rank order of solubility at any temperature wae found to be in the general order of sulfasoxizole, sulfadimethoxine, sulfasomidine and sulfadiaeine. Solubility was found to be highest in methanol and diminished with increasing chain length of the alcohol.

The solubility magnitude for several of the sulfonamides gave an interesting reversal in 1-decanol and all the results obtained are discussed further in this communication.     

MASS TRANSFER OF SULFUR DIOXIDE TO CONDENSING AQUEOUS AEROSOLS

Sodium chloride aerosols were generated from a 1.0 percent solution and passed through a tubular furnace, then recondensed at 29°C in a cooling section in the presence of SO₂. The dry particles ranged from 0.711 to 0.843 µm and the condensed droplets were in the 1.66 to 2.88 µm range. Final droplet size was varied by controlling the temperature of the nebulizer solution between 17 and 50°C. The SO₂ concentration in the gas phase of the condensing cloud was varied between 0.5x10 - ³ and 2.5 xl0 - ³ atm.

Cloud droplets were separated from the gas stream in a point-to-plane electrostatic precipitator and the droplets analyzed colorimetrically for total sulfur content.

Concentrations of SO₂ in the aqueous phase were about one order of magnitude greater than values obtained from equilibrium constants. The collection rate of SO₂ at 29°C appeared to be first order in SO₂ gas phase concentrations.

A model for this process was constructed, based on the hydrate formation in the gas-water interface[SO₂]_g + n[H₂O]ℓ ⇋ [SO₂ · n(H₂O)]ℓ

The order of the hydrate n was estimated to be 4.0.     

The Structure Investigation of Magnesium Soap - Hydrocarbon System

The gels of Mg-stearate (2,5-20%) in apolar liquid paraffin media have been prepared with heating the binary mixture to 120-130°c, to reach the critical solution temperature (CST), and subsequently slowly (spontaneously) cooled to room temperature.

The particular components (i.e. Mg-stearate, liquid paraffin), the binary mixture (suspension) and the prepared gels and colloidal dispersions respectively were studied by means of DSC, to get the wiev into the system formation course and also to get the information about their thermal characteristics.

These results, in connection with those obtained through Theological investigation, determination of oil number and TEM micrographs, have given the following conception: on heating the metallic soap in liquid paraffin is dissolved in the range of CST and gives on cooling a gel or a colloidal dispersion (considering the Mg-stearate concentration) with spherical and planar (lamelar) structures of inverted type.

From rheological standpoint the gels represent plastic systems with well recognised yield value and thixotropy.

The rewarm of formed gels doesn't give stable ones anymore; their instability is the consequence of the lost water traces what confirms the TG curve.     

Physicochemical characterization of rutaecarpine-loaded microemulsion system

To develop an o/w microemulsion system containing poorly water-soluble rutaecarpine, the solubility of rutaecarpine in water, ethanol, various oils, and surfactants were investigated. Among the surfactants and oils tested, Tween 20/PEG 400 and castor oil were chosen as the surfactant system and oil phase of the microemulsion, as rutaecarpine was most soluble in them, respectively. Pseudoternary phase diagrams were constructed to obtain the concentration range of oil, surfactant, and cosurfactant for microemulsion formation, and the stability test of rutaecarpine delivered by microemulsion formation was then evaluated. Pseudoternary phase diagrams show that the areas of microemulsion appeared at those with 0-20% Smix (PEG 400/Tween80 = 60/40), 64-81% water, and 10-20% oil. The rutaecarpine (300 µg/g)-loaded microemulsion composed of 10.8% PEG 400, 7.2% Tween 80, 20% caster oil, and 72% water was physically and chemically stable for at least 6 months. Thus, the microemulsion system composed of castor oil, PEG 400, Tween 80, and water could be a stable dosage form for rutaecarpine.     

Soft Magnetic Properties of Fe-5wt%Al Alloy

In this investigation, a new soft magnetic material (iron with 5 wt% aluminum) has been developed using powder metallurgy processing. The microstructure and the magnetic properties of this new P/M alloy have been characterized at both room and elevated temperatures (up to 500°C). The influence of post-sintering (after initial processing) on the porosity and magnetic properties of this material has also been examined.

Test results show that the room temperature soft magnetic properties of this alloy are comparable to other commercially available soft magnetic materials such as P/M pure Fe, Fe-Si, Fe-P, etc. Post-sintering at 1316°C resulted in significant grain growth and lower porosity with more rounded pore morphology and improved the magnetic properties. While the magnetic induction of the alloy was essentially constant from room temperature to 500°C, the coercivity of the material decreased significantly at elevated temperature. This new P/M alloy may be a suitable soft magnetic material for high temperature (up to 500°C) applications.     

Effect of Storage on the Properties of Acetylsalicylic acid Tablets Coated with Aqueous Hydroxypropyl Methyl-Cellulose Dispersion

The objective of this study was to investigate whether the properties of acetylsalicylic acid tablets coated with aqueous hydroxypropyl methylcellulose dispersion using glycerol or polyethylene glycol 6000 as plasticizer change during storage at 25° or 40°C. Titanium dioxide was used as pigment. The tablets were coated in a fluid bed apparatus. The disintegration time and the release of acetylsalicylic acid during two hours were determined for both uncoated and coated tablets immediately after their preparation and after different storage periods.

When the tablets were stored at room temperature (25°C) the coat protected the core efficiently against changes in the measured parameters as compared with uncoated tablets. However, at higher temperature (40°C) some unfavorable phenomena occurred in the coat and after storage of 48 months, the disintegration time was longer and the dissolution of acetylsalicylic acid slower than from uncoated tablets. Polyethylene glycol was found to be a better protecting agent than glycerol.     

Study of the Relationship Between the Initial Rate of Moisture Sorption/Desorption of Norfloxacin Tablets to the Total Moisture and Temperature of Surrounding Environment

The relationship between absolute moisture content of air (expressed as pounds of water per pound of dry air) at 25°C and 40°C to the initial rate of moisture sorption/desorption of NORFLOXACIN tablets was studied. At the temperatures and relative humidities in the study, linear relationships were observed.

The initial rate of moisture sorption/desorption was found to be dependent upon both the moisture content as well as the temperature of the surrounding environment.     

ELECTROCHEMICAL METALLIZING OF ADVANCED MATERIALS

Electrochemical metallizing provides sound metallurgical coatings for maintenance and production applications. The technique involves tankless electroplating, using a brush-on procedure.

Maintenance applications involve resizing, restoring, rebuilding or resurfacing worn, damaged, corroded, eroded or overmachined metal components. This paper deals with special production applications. The title may be a misnomer, since the paper deals with advanced materials, but also covers special unique applications and infrequently used metals and alloys.

For experimenting with new advanced materials, electrochemical metallizing is invaluable. Manually operated, not requiring large or expensive equipment, enabling rapid controlled deposition of numerous metals, alloys and composites, the system provides a low-cost experimental start-up procedure.

Advanced materials covered are primarily metal composites--nickel with a codeposited fluorinated carbon and a nickel-silicon deposit. The first has a decomposition temperature of 850° to 1000°F (460° to 535°C) and a very low friction coefficient. This makes it useful for high temperatures, low sticking and high wear applications, sometimes replacing Teflon or chromium. The second has a Vickers hardness of HV725 (at 100 grams load) and interesting high hardness applications. Also noted are nickel-silicon carbide, nickel-alumina-silicon dioxide and cobalt composites.

Special application deposits exist for preventing galling; improving brazeability; improved bonding of rubber or plastic to aluminum alloys; aluminum hard coatings; repairing electroless nickel; and light-absorbent surfaces.

Finally, the paper deals with electrochemical metallizing materials infrequently used, e.g. antimony, arsenic, bismuth, gallium, indium, palladium, rhenium, ruthenium, nickel-zinc, nickel-phosphorous, nickel-tungsten and tin-indium.     

The effect of ultrasonic vibration on the compaction characteristics of ibuprofen

An ultrasonic (US) compaction rig has been developed, capable of providing compaction pressure together with high-power ultrasonic vibrations of 20 kHz to a powder or granular material in a die. The rig has been used to investigate the effect of ultrasound on the compaction properties of ibuprofen, a drug with poor compaction properties which produces tablets that are weak and frequently exhibit capping. It was found that coherent ibuprofen tablets could be prepared by ultrasound-assisted compaction at pressures as low as 20-30 MPa. Application of ultrasound before and after compaction was found not to be as effective as ultrasound applied during compaction. The breaking forces of the tablets produced with ultrasound applied during compaction were found to be consistently significantly higher than when compaction was performed conventionally, or with ultrasound applied before or after compaction. Application of ultrasound during compaction made it possible to increase tablet mechanical strength, typically by a factor of 2-5. It was concluded that pressure should be applied together with ultrasound in order to achieve a better acoustical contact, which is required to transmit vibrations from the horn to the material, and also to bond the surfaces of the particles.

Ultrasound application during ibuprofen compaction also resulted in an increase in the apparent density, in relation to the apparent density of conventionally prepared tablets, of up to 14.4%. Ultrasound appears to improve particle rearrangement and provides energy for partial melting of particle asperities and subsequent fusion of particle surfaces, so as to increase interparticulate bonding. Solid bridge formation was thought to result in a reduction of void space, which in turn reduced the rate of water penetration into the compacts and consequently increased disintegration and dissolution times.

It was found that the results of ultrasound-assisted compaction are influenced by formulation and US time. When ibuprofen was mixed with a second material, such as dibasic calcium phosphate dihydrate (DCP) or microcrystalline cellulose (MCC), stronger tablets were prepared by ultrasound-assisted compaction compared to the compacts containing no filler. Positive interactions were considered to have occurred due to ultrasound-induced bonding between the two materials. With an increase in DCP and MCC concentration in ibuprofen formulations, disintegration and drug dissolution rates of the tablets produced with ultrasound significantly increased.

Using temperature-sensitive labels it was found that thermal changes occurred in powdered solids undergoing ultrasound-assisted compaction. Increases in the temperature of tablets were related to US amplitude and US time. With an increase in US amplitude from 5 to 13 µm, the temperature of the DCP tablet surface increased from 40 to 99°C. With an increase in US time from 1 to 5 sec, the temperature of the surface of ibuprofen tablets increased from 43 to 60°C. Increased tablet temperature was thought to be due to ultrasonic energy dissipation turned into heat.

X-ray powder diffraction (XRD) studies of ibuprofen tablets prepared by ultrasound-assisted compaction at 32 MPa revealed that no changes in chemical or/and crystalline structure of the material occurred when ultrasound was applied for up to 5 sec (US amplitude 7 µm). An XRD study of DCP tablets produced by ultrasound-assisted compaction at 32 MPa with ultrasound of different amplitudes (5, 7, 13 µm) applied for 2 sec indicated that no material deterioration occurred in all the tested samples.     

Effects of surfactant on release characteristics of clonidine hydrochloride from ethylcellulose film

The effects of Tween 80 (polysorbate 80) and Span 80 (sorbitan monooleate) surfactants on release characteristics of clonidine hydrochloride from ethylcellulose 10 and 20 cps matrix films containing castor oil as a plasticizer were investigated. The release rates of drug from these films in water at 37°C were found to increase with the addition of surfactant, which was highest for the film prepared from ethylcellulose 20 cps with Tween 80. The experimental values of the cumulative amount of drug released were found to conform to the solution matrix model. The calculated values of the cumulative amount of clonidine hydrochloride released using the experimentally determined diffusion coefficients were also found to be in good agreement with the observed values.     

Elaboration and Physical Study of an Oxodipine Solid Dispersion in Order to formulate Tablets

When drugs particles are very hydrophobic, the carrying out of solid dispersion is a good process in order to obtain a faster drugh dissolution due to the particle the particle size reduction and due to the wettability improvement of the particle surfaces.

The behaviour of these products may differ according to their physical structure, more particularly the dissolution rate of the drug and the stability of the solid dispersion obtained.

The aim of this work is

— to study a product supplied by industry, that is to say a Coprecipitate obtained by evaporation of an ethanolic Oxodipin/Povydone solution. The high melting point of Oxodipin has conduct us to choose coprecipitation. The oxodipin amount in the coprecipitate (20%), is a good compromise between efficiency and technological properties.

— to demonstrate that the product obtained is a solid dispersion.

— to test its stability during compression and during the stockage ether in ambient condition, or at 40° C, or in controled humidity conditions.

Results seem to demostrate that a solid disperision which is a solid solution is obtained. This solid dispersion presents a very good stability of its physical structure and of dissolution properties.     

Thermodynamics of Aqueous Solutions of Alkyl p-Aminobenzoate

The solubilities of a series of alkyl p-aminobenzoates were determined in water at three temperatures. The solutes chosen were the methyl through the n-butyl p-aminobenzoates and the temperatures studied were 25°, 33° and 40°. These compounds present a chemically related series differing by methylene additions in incremental steps. The solubility determinations at various temperatures enabled calculation of thermodynamic elements in aqueous systems.

A recurrent non-linear pattern was obtained in the calculated and experimentally derived thermodynamic values of enthalpy, entropy, and free energy. However, an approximately linear relationship of chemical structure and the partial excess free energy for these solutes was found for these aqueous solutions.     

In vitro release properties of caffeine. I. effect of concentration and type of ointment base

Caffeine has recently been found to cure atopic dermatitis, presumably by increasing skin levels of cAMP.In the light of these findings, its release from different ointment bases at varying concentrations was investigated in vitro. The ointment bases used were a petrolatum (named as petrolatum A), a PEG ointment (USP XVIII), a hydrophilic ointment (USP XVIII), and a w/o type emulsifying ointment. It was incorporated into ointment bases at 1,5,10,20 and 30% (w/w) concentrations, by simple trituration technique.

Release experiments were carried out at 37°C, with diffusion cells which were placed in distilled water filled beakers.

For all caffeine concentrations used, the release was highest from the PEG ointment. It decreased with the hydrophilic ointment, the emulsifying ointment, and petrolatum A, in that order. From both petrolatum base and the PEG ointment, release of caffeine increased significantly with increasing concentrations. As for the hydrophilic and emulsifying ointments, release patterns were found to be independent of concentration for some percentages of caffeine.