Issues Surrounding MDI Formulation Development with Non-CFC Propellants

Kontny, M.J.; Destefano, G.; Jäger, Peter; McNAMARA, D.P.; Turi, J.S.; Campen, L. Van

doi:10.1089/jam.1991.4.181

Cited by 22 publications

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“…This has led to the development of marketing activities for biodegradable packaging [14], products without phosphate or without C.F.C. [15], in short a whole range of products or industrial attitudes seeking to be designated as ecological.…”

Section: Introductionmentioning

confidence: 99%

Environmental communication in Moroccan enterprises: progress, transition and practice

Haouari¹,

Makan²,

Ghmari³

2018

Ann Environ Sci Toxicol

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This study consists essentially of a review of the available literature sources concerned about environmental communication aspect and its context in Moroccan enterprises. Firstly, the progress and effort made to anchor environmental communication and sustainable development principles are presented despite diffi culties encountered to meet this challenge. Moreover, emphasis was placed upon the transition from environmental communication as theoretical aspect concretely towards green economy. It turned out that the green economy construction, as this is a process to be carried out, will not happen without establishment of innovative partnerships with the private sector, local authorities and civil society. Finally, environmental communication practices in Moroccan SMEs have been enlightened and discussed. It was found that the commitment level of Moroccan companies to environmental communication and CSR was one of the most advanced in Africa, the Maghreb and the Arab world.

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Section: Introductionmentioning

confidence: 99%

Environmental communication in Moroccan enterprises: progress, transition and practice

Haouari¹,

Makan²,

Ghmari³

2018

Ann Environ Sci Toxicol

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“…20 years and there are still major challenges to be overcome in using HFAs as working fluids, especially in the pharmaceutical industry. These challenges can be to a large extent attributed to the unique solvation properties of HFAs. , Another major working fluid switch is happening now and is being largely driven by the EU regulations on fluorinated gases that were put forth in 2011. The mandate by the European regulatory agencies dictates that all new model vehicles should use refrigerants with GWP < 150 .…”

Section: Introductionmentioning

confidence: 99%

Understanding Solvation in the Low Global Warming Hydrofluoroolefin HFO-1234ze Propellant

Yang

Rocha

2014

J. Phys. Chem. B

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Hydrofluoroolefins (HFOs), with zero ozone-depleting effect and very low global warming potential, are considered to be the next-generation high-pressure working fluids. They have industrial relevance in areas including refrigeration and medical aerosols. One major challenge expected in the replacement of existing working fluids with HFOs is the solubility and solvation of additives in such hydrophobic and oleophobic low dielectric semifluorinated solvents. The study of the solvation of chemistries that represent those additives by HFOs is, therefore, of great relevance. In this work, we systematically investigate how the polarity and structure of fragments (the tail, t) that represent those additives affect their binding energy (Eb) with HFO-1234ze (1,1,1,3-tetrafluoropropene) (the solvent, s; Eb(st)). We also compare and contrast those results with those for the working fluids that are most widely used in the industry, the hydrofluoroalkanes (HFAs) HFA-134a and HFA-227. Three main chemistries were investigated: alkanes, ethers, and esters. It was found that HFO-1234ze interacts quite favorably with ethers and esters, as indicated by their Eb(st), while Eb(st) with alkanes was much lower. While ether and ester groups showed little difference in Eb(st), the much lower self-interaction energy between ether tail-tail fragments (Eb(tt)) is expected to result in improved solubility/solvation of those groups in HFO-1234ze when compared with the more polar ester groups. The ratio Eb(st)/Eb(tt) is defined as the enhancement factor (Eenh) and is expected to be a better predictor of solubility/solvation of the tail fragments. The branching of the tail groups upon the addition of pendant CH3 groups did not significantly affect the solvation by the propellant. At low branching density (one CH3 pendant group), it did not affect tail-tail self-interaction either. However, at high enough branching (two CH3 groups), steric hindrance caused a significant decrease in Eb(tt) and thus an increase in Eenh, suggesting that branching may be used as a strategy to enhance solvation in HFO propellants. Finally, the solvation behavior of HFO-1234ze was found to be similar to that of HFA-134a, thus suggesting similar considerations may apply for both propellants, when solvation properties are of a concern to the application.

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“…However, the pharmaceutical companies have had to replace the ozone-depleting CFCs by hydrofluoroalkanes (HFAs) propellants because of the phasing out of the former. 1,2) Since HFAs differ from CFCs in their density, polarity and vapor pressure, formulation studies are needed to develop MDI containing HFAs. [3][4][5] Surfactants act as dispersing agents and also ensure suspension stabilization, control of crystal growth and lubrication of the metered valve in the suspension MDI formulations.…”

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confidence: 99%

Effect of Lecithin Coating on the Pulmonary Absorption of Furosemide in Rats

Saso

Seki

Fukuchi

et al. 2006

Biological & Pharmaceutical Bulletin

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Metered dose inhalers (MDI) containing chlorofluorocarbons (CFCs) have been used for the delivery of therapeutic agents to the respiratory tract to treat asthma and related diseases. However, the pharmaceutical companies have had to replace the ozone-depleting CFCs by hydrofluoroalkanes (HFAs) propellants because of the phasing out of the former.1,2) Since HFAs differ from CFCs in their density, polarity and vapor pressure, formulation studies are needed to Surfactants act as dispersing agents and also ensure suspension stabilization, control of crystal growth and lubrication of the metered valve in the suspension MDI formulations. [6][7][8] However, most of the surfactants, such as oleic acid, lecithin, and sorbitan trioleate, are insoluble in HFAs. 9) Since surfactants stabilize the suspension and lubricate the metered valve, processes such as coating active drug particles with lecithin are used for formulations of MDI.10,11) The lecithin-coated particles exhibit low cohesivity and act as a lubricant to avoid clogging the inhaler valve. 12)In our previous study, lecithin-coated furosemide was prepared and used for formulation of an MDI with HFA 227. 13)The dosing reproducibility of the MDI containing lecithincoated furosemide was better than that of one containing uncoated furosemide, suggesting that lecithin-coating is useful for formulations of MDI. 13,14) Since lecithin enhances the mucosal absorption of some drugs, the lecithin coating could help improve the bioavailability after dosing using the MDI. 15,16) In the present study, the effect of the lecithin coating on the pulmonary absorption of furosemide after application by an MDI containing HFA 227 was evaluated in rats. In addition, the permeation-enhancing effect of lecithin was investigated using Calu-3 cell monolayers. [17][18][19][20] MATERIALS AND METHODSMaterials HFA 227 (CF 3 CHFCF 3 ; molecular weight, 170.03; boiling point (°C), Ϫ16.8, specific gravity (kg/l, 20°C), 1.412) was provided by Solvay (Hannover, Germany). Lecithin (soybean, LIPOID S 100) was kindly supplied by Lipoid GmbH (Germany). Furosemide (JP-XIV) was obtained commercially and used as uncoated furosemide or to prepare lecithin-coated furosemide. All other chemicals were of reagent grade and used as received.Preparation of Lecithin-Coated Furosemide The lecithin-coated furosemide was prepared as described previously.13) Briefly, the lecithin (0.40 g) dispersed in 80 ml distilled water was kept at room temperature for 1 d and then furosemide (20 g) was dispersed in it by sonicating for 1 min (SU-18TH, Shibata Science, Tokyo, Japan). The resulting suspension was freeze-dried to obtain lecithin-coated furosemide. The content of furosemide in the lecithin-coated furosemide (98.0%) agreed with that calculated from the amounts of furosemide and lecithin used for the preparation.13) The lecithin coating did not affect the appearance under SEM examination, but the results of X-ray photoelectron spectroscopy analysis, demonstrating the presence of phosphorus from lecithin on the surfac...

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Issues Surrounding MDI Formulation Development with Non-CFC Propellants

Cited by 22 publications

References 0 publications

Environmental communication in Moroccan enterprises: progress, transition and practice

Environmental communication in Moroccan enterprises: progress, transition and practice

Understanding Solvation in the Low Global Warming Hydrofluoroolefin HFO-1234ze Propellant

Effect of Lecithin Coating on the Pulmonary Absorption of Furosemide in Rats

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