Some Properties of an Ethoxylated Castor Oil and Ethoxylated Oleyl Alcohol

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.     

Antifungal Activity of Undecylenic Acid Emulsions by Microbiological Methods

Abstract

Two nonionic surfactants (Simulsol 98 and Simulsol OL 50) alone and I:I mixtures, corn oil-undecylenic acid and water formed emulsions, oily isotropic liquid phases, lamellar and hexagonal liquid crystal phases. The optimum release of undecylenic acid from these phases were controlled microbiologically. The active ingredient undecylenic acid, is released more from emulsion systems containing liquid crystals than only liquid crystalline and oily isotropic liquid phases.     

Development and assessment of stable formulations containing two herbal antimicrobials: Allium sativum L. and Eruca sativa miller seed oils

Abstract

Context: Garlic oil and Eruca oil have been reported to have excellent antimicrobial activity. However, the exact knowledge of their required hydrophilic–lipophilic balance (rHLB) values to facilitate their emulsification are still not reported in the literature.

Objective: The objective of this study is to determine rHLB values of Garlic and Eruca oils to formulate an elegant stable cream formulation enriched with both oils.

Materials and methods: Emulsions of both oils were prepared by the bottle method using water, Tween 80 and Span 80. Formulated emulsions were evaluated for creaming index (CI), droplet size, and turbidity to determine rHLB. Utilizing determined rHLB, creams were formulated using a combination of two surfactants, Span 60:Brij 58 (1:2.333) at three different concentrations (2, 4, and 6%).

Results: rHLB of Garlic oil and Eruca oil was determined to be 7.92?±?0.27 and 9.76?±?0.32, respectively. Stable cream (F1) developed with 2% surfactant blend showed elegant rheological properties, the best antimicrobial activity against Staphyococcus aureus ATCC29737, Escherichia coli ATCC25299 S. aureus (MRSA), Malassezia fufur AUMC No. 5173 with no skin irritation. In addition, its texture parameters and pH were found to be consistent over 12 months at 25?±?1?°C and 60% relative humidity.

Discussion: The lowest CI, smallest droplet size, and highest turbidity were obtained at the optimum surfactant concentration in the prepared emulsions. Increasing surfactant blend concentration in cream formulations leads to increasing viscosity and consequently decreasing antimicrobial activity.

Conclusion: Determination of the rHLB of Garlic and Eruca oils allows the ease of preparation of stable, consistent, and non-irritant cream.     

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

Abstract

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.     

Effect of the long chain extender on the properties of linear and castor oil cross-linked PEG-based polyurethane elastomers

Polyurethane (PU) elastomers were elaborated from polyethylene glycol of high molecular weight (MW = 4,000), 1,6-hexamethylene diisocyanate and polyethylene glycol (PEG₁₅₀₀) (MW = 1,500) as a long linear chain extender and/or castor oil as a cross-linker and were obtained in the form of transparent films. These poly(ether urethanes) elastomers are obtained by replacing the short-chain diol monomers with high molecular weight polyethylene glycols (PEG₁₅₀₀). High molecular weight polyethylene glycol (MW = 4,000 and 1,500, respectively) have greater chain length thus producing networks with lower cross-linking densities and higher average molecular weight between two consecutive cross-links. The PU properties were investigated using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, mechanical analysis and thermogravimetry. The results showed that the prepared polyurethanes (PUs) had very good tensile properties. The stress–strain data show that the PU elastomers obtained using a 60/40% OH_PEG1500/OH_{castor oil} ratio have the best mechanical properties. The thermal degradation of the castor oil cross-linked PU elastomers starts at 280–300 °C, compared to the thermal degradation of linear PUs which begins at 220 °C. During storage at 25 °C, the morphology and mechanical properties of the elastomer films have been observed to change in time.     

Polymorphism of Fostedil: Chracterization and Polymophic Change by Mechanical Treatments

Abstract

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.     

Microstructure and properties of warm worked medium carbon steels

Abstract

In response to the growing interest of the automotive industry in warm precision forging, a laboratory study has been conducted to examine the response of selected medium carbon steels to warm working in the range 650–1060°C. The microstructure and tensile and impact properties have been determined after single, double, and multipass rolling operations. The initial work on 080M40 steel was conducted in collaboration with Austin Rover for the production of stub axle forgings. Properties satisfying the BS970 ‘R’ condition were achieved after soaking at 820–900°C and finish working at 730°C, followed by air cooling. The induction hardening response of the warm worked steels was also satisfactory. The addition of vanadium can be used either to increase strength (by adopting a soaking temperature of 1150°C) or to give an improved strength–toughness combination (by using a soaking temperature of 900°C). The properties of warm worked steels are shown to be dependent upon chemical composition, soaking and working temperature, and subsequent cooling rate. The results have been explained in terms of classical structure–property relationships.

MST/727     

Aging martensite above As temperature

Abstract

Maraging steel is normally aged at 480 to 510°C whereas its A_s is below 560°C. In the present study, the specimens were aged at 510°C and 570°C for durations of180 and 10 min, respectively. The hardness, tensile strength, notch tensile strength, and phases formed were determined. The kinetics of the aging process were studied and the activation energies determined. The distribution of precipitates formed was studied using TEM. The results show that a short exposure at 570°C can impart properties comparable to those of the traditionally aged material.     

Transformation characteristics of medium carbon V – Ti – N microalloyed steel for non-quenched/tempered oil well tubes

Abstract

The phase transformation points of a medium carbon V - Ti - N microalloyed steel were determined, as were the continuous cooling transformation curves of austenite heated at 1100 ° C without deformation and heated at 1200 ° C with two pass deformation. The data have been further used to analyse the real production scheme of N80 grade hot rolled non-quenched/tempered seamless tubes. The results have showed clearly that the commonly used 'in line normalisation' is not always necessary in the non-quenched/tempered production process of N80 grade hot rolled seamless oil well tubes. The above viewpoint has been further demonstrated by the microstructural examination of specimens sampled from industrial production.     

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.     

CO2 mitigation potential from biodiesel of castor seed oil in Indian context

Biodiesel has become an interesting alternative to be used in diesel engine, because it has similar properties to the traditional fossil diesel fuel and may, thus, substitute conventional fuel with none or very minor engine modification. This article deals with alkaline transesterfication of castor oil and their properties for engine application. The purpose of the transesterfication process is to lower the viscosity of the oil from 226.82 cS to 8.50 cS ‘at’ 38°C. The flash point values of castor methyl esters are lower than that of castor oil. The density and gross calorific value of castor methyl ester are much closer to those of diesel. If 10% of total production of castor seed oil is transesterfied into biodiesel, then about 79,782 tones of CO₂ emission can be saved on annual basis. The CO₂ released during combustion of biodiesel can be recycled through next crop production, therefore, no additional burden on environment.     

Surface carburised AISI 8620 steel with dual phase core microstructure

Abstract

In this study, the production of dual phase steel structure in the core of surface carburised AISI 8620 cementation steel and the effect of martensite volume fraction on tensile properties have been investigated. For these purposes, surface carburised (~0·8 wt-%C) specimens were oil quenched from 900°C to obtain a fully martensitic starting microstructure. Then specimens were oil quenched from intercritical annealing temperatures of 731 or 746°C to produce dual phase steel structure in the core of specimens with martensite fractions of ~25 or ~50 vol.-% and nearly wholly martensitic microstructure at the surface. Generally, specimens with dual phase microstructure in the core exhibited slightly lower tensile and yield strengths but superior ductility without sacrificing surface hardness than those specimens with fully martensitic microstructure in the core produced by using conventional heat treatment involving quenching from 850 to 950°C. Also tensile strength increased and ductility decreased with increasing martensite volume fraction.     

Development of a taste-masked oral suspension of clindamycin HCl using ion exchange resin Amberlite IRP 69 for use in pediatrics

Purpose: The purpose of this study is to develop an oral suspension of clindamycin resin complex for the potential use in pediatrics.

Methods: Several types of Ion exchange resins were screened for their binding efficiency with clindamycin. In order to develop a suspension formulation, several thickening agents, surfactants, sweeting, and flavoring agents were evaluated for their influence on the release of clindamycin from resinate. Rheological studies were also conducted to select the optimum amounts of the suspending agents. The release profiles of clindamycin in SGF and SIF were also evaluated from freshly prepared suspension and from suspension formulation after storage for 1 month at 25?°C and 40?°C. Clindamycin bitterness threshold was determined based on volunteers’ evaluation, and taste evaluation was conducted in 12 adult volunteers who evaluated the taste of the optimized suspension against clindamycin solution.

Results: Among all resins tested, Amberlite IRP 69 showed the highest binding efficiency to clindamycin. Several excipients were selected into the suspension formulation based on no or minimum influence on the release of clindamycin from the resinate complex. Moreover, xanthan gum was selected as the optimal suspending agent for the suspension. Clindamycin release profiles in SGF or SIF showed 90% release within 30?min from freshly prepared sample. Clindamycin exhibited good stability profiles at 25?°C and 40?°C over 1 month storage. The mean bitterness threshold of clindamycin was 12.5?μg/ml, and taste evaluation study in adults showed sustainable taste improvement for suspension over clindamycin solution.

Conclusion: Clindamycin/resin complexation has shown to be an efficient method to mask the taste of clindamycin and was developed into a suspension formulation that can be used in pediatrics.     

Antifungal Activity of Undecylenic Acid Emulsions by Microbiological Methods

Two nonionic surfactants (Simulsol 98 and Simulsol OL 50) alone and I:I mixtures, corn oil-undecylenic acid and water formed emulsions, oily isotropic liquid phases, lamellar and hexagonal liquid crystal phases. The optimum release of undecylenic acid from these phases were controlled microbiologically. The active ingredient undecylenic acid, is released more from emulsion systems containing liquid crystals than only liquid crystalline and oily isotropic liquid phases.     

Influence of silicon on strength and toughness of 5 wt-%Cr secondary hardening steel

Abstract

The effects of manganese and silicon on the mechanical properties of the 5 wt-%Cr secondary hardening steel H-11 have been investigated. This steel normally contains about 0·5 wt-%Mn and 1wt-%Si. Two other steels were also considered, both identical to H-11, except that one contained no manganese and the other neither manganese nor silicon. The room temperature hardness and impact toughness were determined for the three steels for tempering temperatures ranging from 200 to 600°C. The results indicate that manganese has no influence on the tempering response or toughness of H-11, but that silicon significantly influences both.

MST/506     

Directional solidification of Ni base superalloy IN738LC to improve creep properties

Abstract

The high Cr, Ni base superalloy IN738LC has been directionally solidified on both laboratory and industrial scales using Bridgman and liquid metal cooling (LMC) methods respectively. In the Bridgman experiments, cylindrical rods were grown using a graphite chill with temperature gradient G = 5·0 K mm^-1 and a water cooled copper chill with G = 8·5 K mm^-1, and a wide range of withdrawal rates of R = 60, 120, 240, 600, and 1200 mm h^-1. In the LMC rigs, several turbine blades were grown using a wide range of withdrawal rates of R = 120, 225, 330, 420, and 630 mm h^-1. Grain and dendritic structures in both cylindrical and turbine blade specimens were evaluated in longitudinal and transverse directions. Dendritic segregation of rods was determined with SEM as a function of processing parameters. Some specimens were given a two stage heat treatment followed by tension tests at 25 and 650°C and creep tests at 152 MPa and 982°C, 340 MPa and 850°C, and 586 MPa and 760°C. It was shown that at R = 600 mm h^-1 with water cooled copper chill, directionally solidified rods with a well orientated dendritic structure and better segregation pattern gives higher tensile properties at 25°C and creep properties at 340 MPa and 850°C. Tension and creep tests of turbine blades showed that although the yield and tensile strength of directionally solidified specimens are in the range of conventionally cast ones, the creep properties of the blades have been significantly improved using the LMC process.     

Development and physicochemical characterization of clindamycin resinate for taste masking in pediatrics

Purpose: To evaluate the physicochemical characteristics of clindamycin HCl in a complex form (resinate) with ion exchange resin (IER) (Amberlite IRP69).

Methods: Drug–resin complex was prepared by simple aqueous binding method. Drug binding study was carried out at different drug and resin concentrations. Several physicochemical characterization studies were conducted to evaluate the resinate complex. These studies included flow properties, in vitro drug release in SGF and SIF, DSC, TGA, mass spectroscopy and XPRD evaluations. In addition, stability study of resinate complex was conducted at 25?and 40?°C for up to 1 month.

Results: Clindamycin and Amberlite IRP69 have formed a complex (resinate) and have shown good flow properties, good thermal properties and chemical stability (short term over 4 weeks) at 25 and 40?°C. Clindamycin release profiles from resinate in SGF and SIF have shown immediate release characteristics and release in simulated saliva has shown dependence on water volume.

Conclusion: The clindamycin stable complex with IER (Amberlite IRP69) has the potential for further development as a compatible pediatric liquid formulation (suspension) or a fast disintegrating tablet.     

Release Studies of Neomycin From Different Ophthalmic Ointment Bases

Abstract

The release of neomycin from ten different ointment bases for possible ophthalmic use was monitored using a microbiological agar plate method. An obvious difference in antibiotic release from the various bases was observed. The effect of benzalkonium chloride, as preservative, on the antimicrobial activity of neomycin was studied and found to be dependent on the base used. From the whole set of results for release and stability, after shelf storage for 24 months, Bases No. 9 (containing castor oil, hydrogenated castor oil and cetyl alcohol) and No. 10 (containing liquid paraffin, hard paraffin, glyceryl monostearate and wool fat) were found to be the bases of choice for neomycin ophthalmic ointments.     

Fe–AI–Zn ternary phase diagram at 450°C

Abstract

Several Fe–Al and Fe–Al–Zn alloys were vacuum melted, annealed at 450°C under atmospheric pressure, and then quenched in iced water. The structure and composition of phases were determined using microstructural, X-ray diffraction, and X-ray energy dispersive analyses. The maximum solubility of zinc was found to be 5·3 wt-% in FeAl₃, 20·9 wt-% in Fe₂Al₅, and 2·0 wt-% in FeAl at 450°C. Based on these results, an isothermal section for the aluminium rich corner of the Fe–Al–Zn ternary phase diagram is proposed.

MST/1196     

Structure–property relationships for quenched and tempered flanges made to ASTM A350 LF2 specification

Abstract

The structure–property relationships for quenched and tempered flanges made to the ASTM A350 LF2 specification have been determined. Samples from Al containing and Al free forged flanges have been heated to temperatures in the range 900–1000°C to produce a wide range in γ grain size and quenched in oil or iced water to produce a variety of commercially obtainable microstructures from fine grained ferrite–pearlite to fully bainitic. After quenching, the samples were tempered at 600°C, and the Charpy V-notch impact values at ?46°C and room temperature hardness values were obtained. Raising the quenching temperature reduced the impact energy values and increased the hardness. Increasing the cooling rate also increased hardness, but there was little change in impact behaviour. Impact behaviour was found to be mainly dependent on the γ grain size: the coarser the grain size, i.e. the higher the quench temperature, the lower the impact value. The facet size was also found to be related to γ grain size, indicating that the high angle grain boundaries, i.e. γ, bainite colony, and ferrite boundaries, were the main obstacles to crack propagation. Increasing the cooling rate from the austenitising temperature increased hardness without significantly affecting the impact behaviour. It is believed that the expected deterioration in impact behaviour associated with an increase in hardness was offset by a refinement of the carbides and the removal of the long carbides situated at the interlath ferrite boundaries. The impact energy in joules at ?46°C was given by the equation: impact energy absorbed at ?46°C=82+18·6d^?1/2?0·8H+0·05CR, where d is austenite grain size in millimetres, H is hardness HV10, and CR is cooling rate in K min^?. To meet the ASTM A350 LF2 impact requirement, the γ grain size should be below 40 μm, and this necessitates a grain refining addition.

MST/771