Sodium Isopropyl Research Articles

Role of sodium l-cysteine alginate conjugate and isopropyl myristate to enhance the permeation enhancing activity of BCS class III drug from TDDS; optimization by central composite design and in vivo pharmacokinetics study

Objective The objective of the present research was to study the effect and optimization of sodium alginate l-cysteine conjugate and permeation enhancer on permeation of high soluble low permeable ropinirole hydrochloride from the transdermal formulation. Methods Sodium alginate l-cysteine conjugate was prepared and characterized and the same was added into a transdermal formulation along with IPM as a permeation enhancer. Twelve primary formulations were prepared by solvent casting method and evaluated. The results were fed into Design Expert® Software to obtain optimized formulation. The optimized formulation was evaluated for physicochemical, ex vivo permeation, stability, skin irritation, and pharmacokinetic studies. Results The results of the characterization of prepared sodium alginate l-cysteine conjugate confirmed the thiolation process. Stability studies suggested that the drug was compatible with all the excipients. SEM images of the transdermal patch revealed that the amorphous drug was uniformly distributed. From the design space, the optimized formulation from the polymer’s ratio (SA: SACC; 4:6) and IPM 9.5%w/w of polymers weight showed target steady state flux 9.004 µg/cm2/h with maximum drug permeation. The increased target flux and maximum drug permeation from an optimized patch suggested that there was an effect of SACC on ropinirole hydrochloride permeation in the presence of IPM as a permeation enhancer. Pharmacokinetic studies in rabbits showed that the optimized patch improved bioavailability as compared to marketed oral tablets. Conclusions The study was concluded that there was a positive effect of sodium alginate l-cysteine conjugate and IPM on ropinirole hydrochloride permeation from the transdermal formulation.

The use of canola oil as an environmentally friendly flotation collector in sulphide mineral processing

The efficiency of mineral flotation relies on the ability to selectively recover different value minerals into their respective concentrates at optimum grades and recoveries based on the differing hydrophobicities. Many of the common hydrophobizing reagents (collectors) currently used in flotation have significant occupational and environmental implications, and hence there is a quest for environmentally benign chemical additives that give similar or better performance than the more toxic conventional reagents. In this paper, we provide substantial experimental evidence that the use of edible, fatty acid-based oils (canola and palm) can foster the flotation recovery of chalcopyrite and molybdenite minerals more selectively against pyrite than the conventional collectors, sodium isopropyl, potassium amyl xanthates and diesel oil.Single and mixed chalcopyrite/pyrite minerals and plant sulphide ores’ flotation studies using canola and palm oils, in contrast with conventional collectors, are reported herein. The results indicate greater efficacy of the canola and palm oils in comparison with the conventional collectors for chalcopyrite and molybdenite recoveries and product upgrades. This is believed to be due to the edible oils’ specific interactions with iron oxides sites preferentially formed in situ on the surfaces of the chalcopyrite or molybdenite in the pulp rather than on the pyrite surfaces, causing limited recovery of the pyrite. Complementary contact angle results confirmed that more canola oil is adsorbed onto chalcopyrite surfaces than onto pyrite surfaces. For the mineral mixtures tested, the edible oil’s degree of unsaturation had a noticeable effect on its performance as a collector. A higher pyrite recovery and slightly lower chalcopyrite grade was obtained with palm oil than with canola oil. These findings suggest that the use of canola oil has a potential to add to the existing array of flotation collectors and would represent a combined opportunity for both the mining and agricultural sectors, with concomitant health, environmental and economic benefits.

식품보존에 이용된 식물의 천연보존료 함유량 연구

To examine the levels of preservatives that occur naturally in food, wild plants used as commercial teas, rice cakes, or spices were studied according to the method of the Korean Food Code and analyzed with a gas chromatograph and HPLC. The levels of the natural preservatives (sodium dehydroacetate, sorbic acid, benzoic acid, methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, isopropyl p-hydroxybenzoate, propyl p-hydroxybenzoate, isobutyl p-hydroxybenzoate, butyl p-hydroxybenzoate, and propionic acid) in 21 cases were investigated against 15 kinds of wild plants. Six of 15 kinds of wild plants, such as pine needles, bamboo leaf, kudzu leaf, ramie leaf, mugwort, and nut pine leaf, were confirmed to have had sorbic acid, benzoic acid, and propionic acid. 8.201-21.839 mg/kg of benzoic acid was detected in the bamboo leaf, ramie leaf, pine needles, mugwort, kudzu leaf, and nut pine leaf. The sorbic acid contents of the bamboo leaf and the kudzu leaf were 5.630-24.995 mg/kg, respectively. The propionic acid content of the ramie leaf was 61.324-62.726 mg/kg. Nine kinds of wild plants, such as the Korean berchimia leaf, taro leaf, sasa borealis, lotus leaf, kuansh, chrysanthemum zawadskii, oak tree leaf, Chinese pepper leaf, and persimmon leaf, were not detected at the levels of the natural preservatives.

The effect of permeation enhancers on the viscosity and the release profile of transdermal hydroxypropyl methylcellulose gel formulations containing diltiazem HCl

Background and Method: The objective of this study was to characterize the release of Diltiazem HCl (DTM HCl) from hydroxypropyl methylcellulose gels containing the following permeation enhancers at a 0.5% (w/w): sodium lauryl sulfate, dimethyl sulfoxide (DMSO), polysorbate 80, propylene glycol, N-methylpyrrolidone (NMP), fatty acids (oleic acid, caprylic acid, and myristic acid), and isopropyl myristate (IPM). The enhancers' effects on the gel's viscosity were also investigated. Results: The novel findings of this study were the following: (i) polysorbate 80 was used for the first time as an enhancer with a hydrophilic compound in a hydrophilic carrier and it rendered the highest permeation flux (57.1 ± 0.9 μg/cm2/h) compared with the rest of the enhancers, (ii) myristic acid (a 14-carbon-chain fatty acid) rendered the highest permeation flux (18.4 ± 0.49 μg/cm2/h) among all fatty acids because of a decrease in the gel's viscosity, (iii) NMP (46.5 ± 0.7 μg/cm2/h) and IPM (15.3 ± 0.41 μg/cm2/h) increased the permeation flux from the second day onward. Both enhancers increased the gel's viscosity, (iv) sodium lauryl sulfate decreased the viscosity of the gel and the drug's permeation flux (8.1 ± 0.21 μg/cm2/h) because of its binding with the drug, (v) propylene glycol decreased the permeation flux (10.2 ± 0.32 μg/cm2/h) by increasing the gel viscosity, and (vi) DMSO increased the permeation flux (13.8 ± 0.4 μg/cm2/h) without altering the viscosity. Conclusion: These findings indicate that to formulate DTM HCl into a hydroxypropyl methylcellulose gel the enhancers of choice should be polysorbate 80, myristic acid, DMSO, NMP, and IPM or combinations thereof.

New method for synthesis of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropylthiocarbamates by oxidation of ammonium salt of xhantogenic acid

A synthesis of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates by oxidation of ammonium salt of ethyl and isopropylxanthogenic acid in a presence of sodium hypochlorite and hydrogen peroxide were performed. Ammonium salt of ethyl and isopropylxanthogenic acid was obtained by the reaction of alkylammonium sulfate and sodium ethyl and isopropyl xanthate. Studies on a dependence of N-ethyl-O-isopropylthiocarbamate yield and purity with respect to reaction parameters (reaction time, molar ratio of oxidant and ethylamonium salt of isopropylxanthogenic acid) were performed. Optimal reaction conditions for synthesis of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates were established. Synthesized compounds have been fully characterized by FTIR, 1H NMR and MS data, while purity has been determined by GC method. A plausible pathway for the N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates synthesis, in the presence of the oxidative agents sodium hypochlorite and hydrogen peroxide, was proposed. The presented synthetic methods has been developed at laboratory and applied at semi-industrial level. The developed optimal method provides a powerful and versatile method for the preparation of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates. This new optimized method offer several benefits, namely, simple operation, mild reaction conditions, bypass of hazardous organic solvents, moderately toxic and inexpensive reagents, and also short reaction times and high product yields.

Basic Analysis on Severe Accidents for Chemical PCB Detoxification Plant Using the UV/Catalyst Method.

Implementation of polychlorinated biphenyls detoxification is being accelerated globally. We have developed an environmentally sound chemical polychlorinated biphenyls detoxification plant (codenamed: HMI), using the Ultraviolet ray (UV)/Catalyst Method. Safety analysis greatly facilitates communication on the subject of risk between the entity wishing to construct and operate the plant and the local residents. In the UVlCatalyst Method, PCB is mixed with sodium hydroxide (NaOH) and isopropyl alcohol (IPA: solvent) to realize PCB concentration in IPA of 1 wt% and subsequently PCB is dechlorinated by two independent process steps. The first step is the UV irradiating process (UV process), and the second step is the catalyst reaction process. As a result, biphenyl, NaOH, acetone, and water are generated after PCB is dechlorinated. A distilling column is designed in order to separate IPA from the solution, and IPA can be recycled many times as a solvent of PCB. IPA and acetone may form an inflammable mixture after leakage. Concerning HM1, first, hazardous events which produce severe accidents were identified by Failure Mode and Effect Analysis (FMEA); and secondly, leak of isopropyl alcohol (IPA), that causes fire/explosion, is defined as the most serious event. Based on this result, numerical safety analyses were carried out and the following findings were obtained. Thermal runaway experiment of residual liquid in the bottom of a distilling column: It was confirmed experimentally that no possibility of thermal runaway exists. Stress analysis of the distilling column after fire/explosion: The strength of the distilling column was proved. Impact evaluation concerning the surrounding facilities and residents after fire/explosion: It was confirmed that impact would be slight. Impact evaluation concerning exposure of residents to PCB: Exposure of residents to PCB would be negligibly small. In conclusion, the standardized methodologies for both safety evaluations and procedures concerning PCB plants were proposed and their validity verified.

CHEMICAL COMMINUTION OF COAL

Chemical comminution is an effective means for size reduction and beneficiation of coal. Sodium hydroxide and isopropyl alcohol (IPA) show synergism in chemical comminution of Illinois No. 6 bituminous coal. This system is effective at low alkali concentrations with low consumption of NaOH. Much of the NaOH consumed is for neutralization of acidity of the coal. The IPA serves only as a reaction medium and could be recovered nearly quantitatively for recycling. The system lends itself to application in preparation of coal-water mixtures and coal-alcohol slurry fuels.

The toxicity of various mining flotation reagents to rainbow trout ( Salmo gairdneri)

Preliminary testing of eight collectors (xanthates) and four frothers in 96-h static and 28-day flow-through bioassays using rainbow trout as the test organism show a great disparity in the toxicity of the chemicals administered in these two ways. For the short-term tests, the relative toxicity of the compounds is expressed as an lc 50 or as a range of concentration in mg l −1 in which the lc 50 is expected to fall. Of the collectors tested in this way sodium ethyl and potassium amyl xanthate were the most toxic, with lc 50's in the range of 30–50 mg l −1. Among the frothers, xylenol (cresylic acid) was found to be the most toxic ( 5.6 mg l −1 > lc 50 > 3.2 mg l −1 ) while polypropylene glycol was least toxic ( lc 50 > 1000 mg l −1 ). The long-term tests using potassium ethyl, sodium isopropyl, sodium ethyl, and potassium amyl xanthate indicated that in the flow-through system, the toxicity of the chemicals was in the order of 100 fold greater compared with the static bioassay results.

Exchange Reactions of Iodine Compounds

JULIUSBURGER, Topley and Weiss1 found by the artificial radioactive indicator method that an exchange takes place between sodium iodide (c. 0.5M) and methyl iodide (c. 2M) in alcoholic solution at room temperature ; the exchange is complete in a minute or two. Under similar conditions, allyl iodide exchanges with sodium iodide, but ethyl, propyl, isopropyl and methylene iodides do not ; nor does iodoform exchange in acetone solution. Further, Gluckauf and Fay's2 successful concentration of active iodine from methyl iodide after neutron bombardment shows that no appreciable exchange occurs between iodine and methyl iodide in the absence of a solvent.