Factorial approach for the optimization and development of stability indicating study of the contraceptive suspension for injection(Depo-Provera®)

The study involves use of factorial design for optimization of forced degradation conditions and development of stability indicating method for medroxyprogestrone acetate (MPA) or depo-provera as known in the market. MPA is an important contraceptive and anticancer drug especially for treatment of breast cancer and it is the first time to study the different conditions affecting its stability. MPA was subjected to different variables such as solvent type, pH and the time subjected to UV light. Factorial design has been used during forced degradation to determine significant factors responsible for degradation and to optimize degradation conditions reaching maximum degradation. Factors responsible for forced degradation were statistically evaluated using Bubble and Surface plots. Variables proved to be significant (p < 0.05) and the suggested model represented a perfect example for indicating the efficiency of factorial designs in optimizing the degradation conditions that give maximum percent of degradation. We investigated also the solubility and stability profiles of MPA in aqueous solutions. Stability study results showed a very low stability profile of MPA in all the aqueous solutions with rapid degradation rate more than other solvents. The current research may contribute to enrich the knowledge of the physicochemical properties of this drug for exploring its full anticancer potential in the future.

Modeling Aggregate Exposures to Glycol Ethers from Use of Commercial Floor Products

Computer modeling of aggregate exposure provides the capability to estimate the range of doses that can occur from product use and to understand the relative importance of different routes of exposure. This paper presents an assessment of aggregate occupational exposure to two glycol ethers used as solvents in floor maintenance products for industrial and institutional facilities, using a simulation tool named PROMISE. Three commercial floor-care products were assumed to be applied in sequence—a floor stripper, then a floor cleaner, and lastly a protective coating. The glycol ethers modeled were ethylene glycol butyl ether (EGBE) in the floor stripper and in the floor cleaner, and dipropylene glycol methyl ether (DPGME) in the coating. Modeling uncertainty was assessed through a comparison of the PROMISE inhalation exposure estimates with those from an independent model (MCCEM), and parameter uncertainty was investigated using PROMISE software’s Monte Carlo simulation capabilities. Modeling results indicated that inhalation is the dominant exposure route. The predicted average air concentration and inhalation dose from PROMISE agreed with the second model (MCCEM) within 10%. Monte Carlo simulation indicated that the upper end of the aggregate-dose distribution for the scenario was more than 50% higher than the value of the point estimate. The modeled 8-h TWA concentrations for EGBE and DPGME were lower than the corresponding permissible exposure limits American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLV) by at least a factor of 20, indicating that under the assumed conditions work-place exposures to glycol ethers are below levels of concern.

European solvent industry group generic exposure scenario risk and exposure tool

The European Solvents Industry Group (ESIG) Generic Exposure Scenario (GES) Risk and Exposure Tool (EGRET) was developed to facilitate the safety evaluation of consumer uses of solvents, as required by the European Union Registration, Evaluation and Authorization of Chemicals (REACH) Regulation. This exposure-based risk assessment tool provides estimates of both exposure and risk characterization ratios for consumer uses. It builds upon the consumer portion of the European Center for Ecotoxicology and Toxicology of Chemicals (ECETOC) Targeted Risk Assessment (TRA) tool by implementing refinements described in ECETOC TR107. Technical enhancements included the use of additional data to refine scenario defaults and the ability to include additional parameters in exposure calculations. Scenarios were also added to cover all frequently encountered consumer uses of solvents. The TRA tool structure was modified to automatically determine conditions necessary for safe use. EGRET reports results using specific standard phrases in a format consistent with REACH exposure scenario guidance, in order that the outputs can be readily assimilated within safety data sheets and similar information technology systems. Evaluation of tool predictions for a range of commonly encountered consumer uses of solvents found it provides reasonable yet still conservative exposure estimates.

Measurement, standards, and data needs for CO2 capture materials: a critical review

The commercial deployment of cost-effective carbon capture technology is hindered partially by the lack of a proper suite of materials-related measurements, standards, and data, which would provide critical information for the systematic design, evaluation, and performance of CO2 separation materials. Based on a literature search and conversations with the carbon capture community, we review the current status of measurements, standards, and data for the three major carbon capture materials in use today: solvents, solid sorbents, and membranes. We highlight current measurement, standards and data activities aimed to advance the development and use of carbon capture materials and major research needs that are critical to meet if innovation in carbon capture materials is to be achieved. The review reveals that although adsorbents are considered to have great potential to reduce carbon capture cost, there is no consensus on the experimental parameters to be used for evaluating sorbent properties. Another important finding is the lack of in situ experimental tools for the structural characterization of solid porous materials during CO2 adsorption, and computational methods that would enable a materials-by-design approach for their development.

International Conference on Harmonisation; final recommendation for the revision of the permitted daily exposure for the solvent cumene according to the maintenance procedures for the guidance Q3C Impurities: Residual Solvents; availability. Notice

The Food and Drug Administration (FDA) is announcing the availability of a final recommendation for the revision of the permitted daily exposure (PDE) for the solvent cumene according to the maintenance procedures for the guidance for industry entitled ``Q3C Impurities: Residual Solvents.'' The recommendation was prepared under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH).

Extraction of antioxidants from spruce (Picea abies) bark using eco-friendly solvents

INTRODUCTION

Antioxidants are known to avert oxidation processes and they are found in trees and other plant materials. Tree bark is a major waste product from paper pulp industries; hence it is worthwhile to develop an extraction technique to extract the antioxidants.

OBJECTIVE

To develop a fast and environmentally sustainable extraction technique for the extraction of antioxidants from bark of spruce (Picea abies) and also to identify the extracted antioxidants that are abundant in spruce bark.

METHODOLOGY

A screening experiment that involved three different techniques was conducted to determine the best technique to extract antioxidants. The antioxidant capacity of the extracts was determined with DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. Pressurised fluid extraction (PFE) turned out to be the best technique and a response surface design was therefore utilised to optimise PFE. Furthermore, NMR and HPLC-DAD-MS/MS were applied to identify the extracted antioxidants.

RESULTS

PFE using water and ethanol as solvent at 160 and 180°C, respectively, gave extracts of the highest antioxidant capacity. Stilbene glucosides such as isorhapontin, piceid and astringin were identified in the extracts.

CONCLUSION

The study has shown that PFE is a fast and environmentally sustainable technique, using water and ethanol as solvent for the extraction of antioxidants from spruce bark.

Quantitative property-property relationships for computing occupational exposure limits and vapour hazard ratios of organic solvents

Vapour Hazard Ratio (VHR) is used in solvent substitution to select the best replacement option regarding overexposure potential of solvents. However, VHR calculations are limited by the availability of Occupational Exposure Limits (OELs). The overall objective of this study was to develop quantitative property-property relationship (QPPR) approaches for computing OELs, in view of supporting the derivation of VHRs for solvents without OELs. QPPRs were developed for estimating OELs using a database of 88 solvents which have health-based Time-Weighted Average (TWA) OELs published by the American Conference of Governmental Industrial Hygienists (ACGIH). Three surrogates of biotic lipid : air partition coefficients [n-octanol : air (K(oa)), olive oil : air (K(oila)) and fat : air (K(fa))] were selected for evaluating the descriptive/predictive relationship with OELs for solvents with local modes of action. For solvents with systemic modes of action, the prediction of OEL needs to consider quantitative differences in toxicokinetics (i.e. kinetic variability factor, KVF) and toxicological potency (i.e. effective internal concentration, EIC). The n-octanol : water (K(ow)), the oil : water (K(oilw)) and the fat : water (K(fw)) partition coefficients were selected for evaluating the relationship with EICs. For local modes of action, K(oa) is the most accurate predictor of OELs [OEL (ppm) = 10(((-0.45 x log K(oa)) + 3.65)); n = 21, r²= 0.71, PRESS/SSY = 0.36, F = 45.5 with p < 0.001] and the mean (±SD) (range) of the recommended to predicted OELs was 1.04 ± 0.61 (0.2-2.5). For systemic modes of action, KVFs and EICs vary in a range from 0.73 to 41.4 µmol L⁻¹ and 1.20-848 µmol L⁻¹, respectively. K(ow) is an accurate predictor of calculated EICs [EIC (µmol L⁻¹) = 10 (((-1.16 x log K(ow)) + 3.65)); n = 27, r²= 0.88, PRESS/SSY = 0.12, F = 181 with p < 0.001] and 50% of the predicted OEL values were within a factor of two of the recommended TWA OELs. Overall, 61% and 87% of the predicted VHRs were within a factor of two and five, respectively, of the calculated VHRs. The QPPR models developed in this study represent potentially useful tools for estimating provisional OELs for solvents lacking such guideline values. These provisional OELs are developed only to support initial estimations of VHR for dealing with the challenge of solvent substitution where relative values rather than absolute values of OEL and vapour pressure guide the hygienist in making pragmatic decisions for managing occupational health hazards.

Investigation of fatty acid esters to replace isopropyl myristate in the sterility test for ophthalmic ointments

Several pharmacopoeias recommend the membrane filtration method for the sterility test of ophthalmic ointments. Isopropyl myristate, a fatty acid ester that exhibits high toxicity mainly against Gram-negative microorganisms, is indicated as a solvent for ointments. In this study, six fatty acid esters (diethyl adipate, diisopropyl adipate, ethyl laurate, ethyl myristate, methyl caprylate and isopropyl palmitate) were evaluated as solvents to replace isopropyl myristate in the sterility test for ophthalmic ointments. The logarithm of the partition coefficient (logP) of the fatty acid esters was calculated from the sum of the substituent hydrophobicity constants (pi) of the functional groups present in their molecules. The ability of the solvents to dissolve an ophthalmic ointment base was investigated. The D-value method was used to assess the antimicrobial activity of isopropyl palmitate, ethyl myristate, ethyl laurate and isopropyl myristate against Pseudomonas aeruginosa. Isopropyl palmitate was the least toxic solvent to this microorganism, since it had the highest D-value (171.1 min). No significant difference was observed between the D-values of ethyl myristate (89.4 min) and isopropyl myristate (92.5 min). Ethyl laurate exhibited the lowest D-value (27.2 min). Using gas chromatography coupled to mass spectrometry, other fatty acid esters were detected as the predominant impurities in the solvents, as well as acid contaminants in low or insignificant amounts.

Potential uses of petrochemical products can result in significant benzene exposures: MSDSs must list benzene as an ingredient

According to 29 CFR1910.1200 (Hazard Communication Standard [HCS]), a material safety data sheet (MSDS) must list a carcinogen as an ingredient if its concentration in a product is 0.1% or more by weight. However, according to the HCS, when the concentration of a carcinogen in a product is less than 0.1% (by weight) it may not be necessary to list it as an ingredient on the MSDS. The standard stipulates that if potential uses of the product can result in exposures to the carcinogen that exceed the Occupational Safety and Health Administration (OSHA) permissible exposure limit or the ACGIH threshold limit value (TLV), then it must be listed. This article focuses on the failure of MSDSs to report benzene as a listed ingredient in products that incorporate petroleum-derived ingredients such as toluene and hexane. In the United States, approximately 238,000 people are occupationally exposed to benzene each year. Only rarely is benzene listed as an ingredient on MSDSs even though it often comprises more than 0.1% of petroleum solvents and, when its concentrations in petroleum-derived products are much less than 0.1%, inhalation exposures to benzene can be much higher that its OSHA PEL of one part per million (ppm) by volume (v/v) andACGIH TLV of/one-half ppm (v/v). As a consequence of benzene's omission from MSDSs as a listed ingredient, employers are frequently unaware of their requirement to implement 29 CFR 1910.1028 (Benzene Standard) and of the need to address employee exposures to benzene in the workplace. This article demonstrates that benzene should be listed as an ingredient on MSDSs, even at concentrations in benzene-containing products that are between one and two orders of magnitude below OSHA's 0.1% threshold. An exposure assessment methodology is presented that is applicable to employees whose conditions of exposure are similar to those in the published study. These workers make up a similar exposure group. The information and methodology presented here are germane to preparation of accurate MSDSs for benzene-containing products, employers who must comply with 29 CFR 1910.1028, and retrospectively estimating exposures to benzene.

[Reference values for indoor air: dearomatized hydrocarbon solvents (C(9)-C(14))]

To protect public health the German Joint Working Group on Indoor Guidelines of the Federal Environmental Protection Agency and the States' Departments of Health is issuing indoor air guideline values based on a fixed procedure published in 1996. Regarding dearomatized hydrocarbon solvents/white spirits (DAWS--CAS-No. 64742-47-8, 64742-48-9, 64742-88-7, 64741- 65-7) no human data are available. From animal studies, neurotoxicity, developmental toxicity and reproductive toxicity were identified as critical endpoints. For risk evaluation the Hass et al. (2001) study was used as the pivotal study. Based on effects at 4680 mg DAWS/m(3) for the endpoint developmental toxicity, the lowest adverse effect level for chronic exposure is assessed as 400 mg DAWS/m(3). By applying an interspecies factor of 10, an intraspecies factor of 10 and an additional factor 2 referring to the special physiology of children (higher breath rate compared to adults) a so-called health hazard value of 2 mg DAWS/m(3) indoor air and a so-called health prevention value of 0.2 mg DAWS/m(3) are obtained.

An evaluation of preoperative skin antiseptics

An underpinning tenet of evidence-based practice is that all routine practices should be open to scrutiny. Questioning practice should not be limited to new, experimental procedures, but should also include examination of 'tried and trusted' techniques. Taking this perspective, the author recently contributed to a systematic review evaluating the use of antiseptics preoperatively.

Quantitative Raman Reaction Monitoring Using the Solvent as Internal Standard

Despite its potential, the use of Raman spectroscopy for real-time quantitative reaction monitoring is still rather limited. The problems of fluorescence, laser instability, low intensities, and the inner filter effect often outscore the advantages as narrow bands, the use of glass fibers, and low scattering of water and glass. In this paper, we present real-time quantitative monitoring of the catalyzed Heck reaction by using the solvent as internal standard. In this way, all multiplicative distortions, e.g., laser intensity variations or absorbance of the laser light, can be corrected for. We also show that a limited amount of fluorescence does not hamper the analysis. Finally, we present a new method to correct for the inner filter effect, i.e., the absorbance of Raman scattered light by the reaction medium. Simultaneous absorption measurements of the reaction mixture enable accurate correction of Raman signals for the inner filter effect. Thus, for reaction monitoring applications, a Raman spectrometer should be equipped with an absorbance measurement device.

Metal Elution and Content of Fused Slags Produced from Incinerated Ash

In recent years, trials to reuse fused slags, obtained through the further treatment of incinerated ash produced in the process of the disposal of garbage or sewer sludge, such as for building materials including bricks, have drawn attention. To establish the safety of using such substances, elution tests for metals and metal contents were investigated in this study. As the result of examining 13 slags, which were made by different methods, little elution of toxic metals was found in the elution tests when water was used as a solvent. However when acid was used, there was a tendency for the elution of many kinds of metals to become greater. On other hand, the results of content measurements showed that arsenic and selenium, which were not seen to be eluted from any of the slags tested, were detected; and that aluminum and manganese existed in the slags in high concentrations.

International Conference on Harmonisation; final recommendations on the revision of the permitted daily exposures for two solvents, n-methylpyrrolidone and tetrahydrofuran, according to the maintenance procedures for the guidance Q3C Impurities: Residual Solvents; Availability. Notice

The Food and Drug Administration (FDA) is announcing final recommendations to revise the permitted daily exposures (PDEs) for two solvents, n-methylpyrrolidone (NMP) and tetrahydrofuran (THF), according to the maintenance procedures for the guidance for industry entitled "Q3C Impurities: Residual Solvents." The final recommendations were reached under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH).

Solvent-free sonochemical preparation of ionic liquids

[reaction: see text] An ultrasound-assisted preparation of a series of ambient-temperature ionic liquids, 1-alkyl-3-methylimidazolium (AMIM) halides, which proceeds via efficient reaction of 1-methyl imidazole with alkyl halides/terminal dihalides under solvent-free conditions, is described.

Solute-solvent interactions in micellar electrokinetic chromatography. 6. Optimization of the selectivity of lithium dodecyl sulfate-lithium perfluorooctanesulfonate mixed micellar buffers

The optimization of the composition of mixed surfactants used as micellar electrokinetic chromatography (MEKC) pseudostationary phases is proposed as an effective method for the separation of complex mixtures of analytes. The solvation parameter model is used to select two surfactants (lithium dodecyl sulfate, LDS, and lithium perfluorooctanesulfonate, LPFOS) with contrasting solvation properties. Combination of these two surfactants allows variations of the solvation properties of MEKC pseudostationary phase along a wide range. Thus, the convenient variation of the proportion of both surfactants allows an effective control of the selectivity in such systems. An algorithm that predicts the overall resolution of a given mixture of compounds is described and applied to optimize the composition of the mixed surfactant for the separation of the mixture. The algorithm is based on the calculation of peak purities on simulated chromatograms as a function of the composition of the mixed LDS/LPFOS micellar buffer from data at several micellar buffer compositions. Successful separations were achieved for mixtures containing up to 20 compounds, in less than 12 min.

Assuring quality and performance of sustained and controlled release parenterals: workshop report

This is a summary report of the American Association of Pharmaceutical Scientists, the Food and Drug Administration and the United States Pharmacopoeia co-sponsored workshop on "Assuring Quality and Performance of Sustained and Controlled Release Parenterals." Experts from the pharmaceutical industry, the regulatory authorities and academia participated in this workshop to review, discuss and debate formulation, processing and manufacture of sustained and controlled release parenterals and identify critical process parameters and their control. Areas were identified where research is needed in order to understand the performance of these drug delivery systems and to assist in the development of appropriate testing procedures. Recommendations were made for future workshops, meetings and working groups in this area.

Extraction solvent selection in environmental analysis

A method for the prediction of a suitable solvent for the extraction of pesticides is outlined. The procedure is based on the Hildebrand solubility parameter, delta(t). The solubility parameter is broken down into three individual components, which are calculated by the addition of group contributions. To demonstrate the applicability of the approach pressurized fluid extraction was used to extract 4,4'-DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] and its metabolites, 4,4'-DDD [1,1-dichloro-2,2-bis(p-chlorophenyl)ethane] and 4,4'-DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene], from an historically contaminated soil from the United States and pentachlorophenol from a certified reference material (CRM524) using various solvents. Visual representation of the individual parameters predicted the ideal extraction solvent to be DCM for 4,4'-DDT and its metabolites and a mixture of acetonitrile and dichloromethane (1:1, v/v) for PCP. These findings were confirmed by the experimental results.

Standard state and thermodynamic self-consistency

It is pointed out that even though the standard state for solutions is a fictitious state, it nonetheless should be thermodynamically self-consistent. Using a volumetric constraint, it is shown that the biochemical standard state concentration of 1M is too high for macromolecules like proteins and nucleic acids that it violates volumetric self-consistency. Also, at 1 M standard state, the mole fraction of these macromolecular solutes is not the commonly held value of 1/55.5, but rather a meaningless negative number. Thus, the ideal mixing entropy (also called cratic entropy) cannot be meaningfully calculated for macromolecules at such a standard state. The relevance of this conclusion to the interpretation of standard bimolecular binding entropy is discussed.

An in-use evaluation of an alcohol-based pre-surgical hand disinfectant

OBJECTIVE

To determine whether alcohol hand disinfection is an effective alternative to traditional agents for the pre-surgical scrub.

DESIGN

A prospective clinical trial of a 70% isopropanol pre-surgical hand disinfectant.

SETTING

The operating room suites at two hospital sites in British Columbia.

METHODS

Cases were selected to evaluate both short and longer procedures. The hand disinfectant was compared to agents in current use as surgical scrubs (4% chlorhexidine and 7.5% povidone-iodine). Surgical technique and glove use were not modified. Pre- and postoperative fingertip impression and "glove-juice" cultures were used to determine microbial burden, and hands were evaluated for skin integrity.

RESULTS

There was no statistical difference between the microbial hand counts following use of the alcohol-based product or the current agents, for cases less than 2 hours' duration. Comparison of longer surgical cases revealed significantly better pre- and postoperative culture results with the alcohol hand rinse, but analysis of matched pairs showed no significant difference in microbial counts. The alcohol hand rinse was equivalent to the operative scrub in terms of skin integrity and user acceptability.

CONCLUSION

An alcohol hand rinse was equivalently effective in reducing microbial hand counts as the traditional pre-surgical scrub, both immediately after hand disinfection and at the end of the surgical procedure.

Clinical effectiveness of low-temperature sterilization technologies

The elimination of chlorofluorocarbons by the Clean Air Act has led to the development of alternative technologies for low-temperature sterilization in the healthcare setting, including 100% ethylene oxide, ethylene oxide with other stabilizing gases, immersion in peracetic acid, and gas plasmas. The ideal sterilant does not exist, and infection control professionals should understand the advantages and disadvantages of these processes. However, when combined with adherence to standard cleaning protocols, the available data suggest that the currently available Food and Drug Administration-cleared low-temperature sterilization technologies can inactivate a clinically relevant inoculum of highly resistant organisms.

Identification of bacteria in water for pharmaceutical use

Different systems for the obtention of water used in Biopharmaceutical Industry were characterized from the bacteriological point of view. Determination of aerobic mesophilic microorganisms was performed; as well as the isolation of contaminant microorganisms for what the techniques of membrane filtration was used. For the identification of the more representative species there were made conventional biochemical tests and quick systems: API. The results show that water serving as tap water for purification systems fulfill with the microbiological requirements to this kind of water. All the isolated microorganisms were gram-negative bacteria characteristics of this environment: Pseudomonas putida, Xanthomonas maltophilia, Aeromonas salmonicida ssp. salmonicida, Flavimonas coryzihabitans and Acinetobacter iwoffi. The ultrafiltration and distillation tested systems fulfill with the established microbiological limits, except for deionization and distilled water storing systems. The isolation showed that approximately the 76.9% were of Gram-negative bacteria, the 14.6% of Gram-positive cocci and the 8.5% Gram-positive sporulated bacilli. The most representative genus of purified water were: Pseudomonas, with the higher percent of incidence, Staphylococcus, Bacillus, Flavobacterium, Sphingomonas, Aeromonas and Agrobacterium.

Evaluation of the L5178Y mouse lymphoma cell mutagenesis assay: quality-control guidelines and response categories

A data-based approach to formulating quality-control criteria for the mouse lymphoma cell forward mutation assay is described. Quality-control guidelines for solvent controls, positive controls, and compound-treated cultures were developed based on analysis of over 800 experiments. Frequency distributions of experimental parameters of control cultures, such as mutant frequencies, cloning efficiencies, and suspension growths, were examined. Cloning efficiency and relative total growth affected the variability only when the test chemical was highly toxic. This information was used to generate the quality-control criteria, which were applied to an experiment before it was evaluated for a response. The response categories for classifying the effect of test chemicals on the assay system are defined in terms of (1) the statistically significant differences in average mutant frequency between solvent control cultures and cultures exposed to a chemical and (2) the trend of the dose-related responses.

Improvements in the thin-layer chromatography of natural products. I. Thin-layer chromatography of the aflatoxins

During the period which has elapsed since the aflatoxins were first isolated, one of the main problems has been the separation of the individual aflatoxins in pure form from aflatoxin-containing extracts. This separation has been best effected by thin-layer chromatography, and in this paper we describe how some of the difficulties may be overcome by using an appropriate combination of solvent system and silica gel preparation. For the examination of aflatoxin-containing extracts from the mycelia of Aspergillus flavus moulds, an initial freeze-drying step has been found to improve appreciably the quality of the chromatograms obtained.