Glass Mortar Research Articles

Stability of Extemporaneously Prepared Rufinamide Oral Suspensions

Rufinamide is an oral antiepileptic drug indicated for adjunctive therapy in treating generalized seizures associated with Lennox-Gastaut syndrome. Currently, rufinamide is available as 200-mg and 400-mg tablets. A liquid dosage form does not exist at the present time. Lack of a suspension formulation may present an administration problem for many children and adults who are unable to swallow tablets. The availability of a liquid dosage form will provide an easy and accurate way to measure and administer the medication. To determine the stability of both sugar-containing and sugar-free rufinamide suspensions over a 90-day period. A suspension of rufinamide 40 mg/mL was prepared by grinding twelve 400-mg tablets of rufinamide tablets in a glass mortar. Sixty milliliters of Ora-Plus and 60 mL of either Ora-Sweet or Ora-Sweet SF (sugar free) were mixed and added to the powder to make a final volume of 120 mL. Three identical samples of each formulation were prepared and placed in 60-mL amber plastic bottles and were stored at room temperature. A 1-mL sample was withdrawn from each of the 6 bottles with a micropipette immediately after preparation and at 7, 14, 28, 56, and 90 days. After further dilution to an expected concentration of 0.4 mg/mL, the samples were assayed using high-performance liquid chromatography. Stability was defined as the retention of at least 90% of the initial concentration. At least 90% of the initial rufinamide concentration remained throughout the 90-day study period in both preparations. There were no detectable changes in color, odor, taste, and pH and no visible microbial growth. Extemporaneously compounded suspensions of rufinamide 40 mg/mL in a 1:1 mixture of Ora-Plus and Ora-Sweet or Ora-Sweet SF were stable for at least 90 days when stored in 59-mL amber polypropylene plastic bottles at room temperature.

Stability of extemporaneously prepared moxifloxacin oral suspensions

The stability of extemporaneously prepared moxifloxacin oral suspensions was studied. An oral suspension of moxifloxacin 20 mg/mL was prepared by thoroughly grinding three 400-mg tablets of moxifloxacin in a glass mortar. Thirty milliliters of Ora-Plus and 30 mL of either Ora-Sweet or Ora-Sweet SF were mixed and added to the powder to make a final volume of 60 mL. Three identical samples of each formulation were prepared and placed in 2-oz amber plastic bottles with child-resistant caps and were stored at room temperature (23-25 degrees C). A 1-mL sample was withdrawn from each of the six bottles with a micropipette immediately after preparation and at 7, 14, 28, 60, and 90 days. After further dilution to an expected concentration of 8 microg/ mL with sample diluent, the samples were assayed in duplicate by stability-indicating high-performance liquid chromatography. Stability was defined as the retention of at least 90% of the initial concentration. At least 99% of the initial moxifloxacin remained throughout the 90-day study period in both preparations. There were no detectable changes in color, odor, taste, and pH and no visible microbial growth in any sample. Extemporaneously compounded suspensions of moxifloxacin 20 mg/mL in a 1:1 mixture of Ora-Plus and Ora-Sweet or Ora-Sweet SF were stable for at least 90 days when stored in 2-oz amber plastic bottles at room temperature.

Stability of extemporaneously prepared sodium phenylbutyrate oral suspensions

In an effort to minimize barriers to compliance and adherence and to improve the accuracy of dosage measurement, sugar-containing and sugar-free sodium phenylbutyrate suspensions were formulated, and the stability of these products over a 90-day period was determined. An oral suspension of sodium phenylbutyrate 200 mg/mL was prepared by thoroughly grinding 12 g of Sodium Phenylbutyrate Powder, USP, in a glass mortar. Thirty milliliters of Ora-Plus and 30 mL of either Ora-Sweet or Ora-Sweet SF were mixed and added to the powder to make a final volume of 60 mL. Three identical samples of each formulation were prepared and placed in 2-oz amber plastic bottles with child-resistant caps and were stored at room temperature. A 500-microL sample was withdrawn from each of the six bottles with a micropipette immediately after preparation and at 7, 14, 28, 60, and 90 days. After further dilution to an expected concentration of 100 microg/mL with the mobile phase, the samples were assayed by high-performance liquid chromatography. Stability was defined as the retention of at least 90% of the initial concentration. At least 95% of the initial sodium phenylbutyrate concentration remained throughout the 90-day study period in both preparations. There were no detectable changes in color, odor, taste, and pH and no visible microbial growth in any sample. Extemporaneously compounded suspensions of sodium phenylbutyrate, 200 mg/mL, in a 1:1 mixture of Ora-Plus and Ora-Sweet or Ora-Sweet SF were stable for at least 90 days when stored in 2-oz amber plastic bottles at room temperature.

Experimental study of the mechanical behavior of continuous glass and carbon yarn-reinforced mortars

This work aims to evaluate the possibilities of cementitious materials reinforcement by continuous alkaline resistant AR glass or carbon yarns. Bond flexural tests and flexural tests on 7 × 7 × 28-cm specimens were performed at various ages of the mortar and with various layouts and, volume fractions of yarn. The flexural tests showed the capacity of yarn to improve the strength and ductility of the mortar. A definition of the effectiveness of a yarn as reinforcement is given as proportional to the ratio of the post-cracking maximal load on the product of the strength of yarn and the volume fraction of yarns. The effectiveness of a yarn seems to depend on its structure: the one of the carbon yarn, made up of micrometric filaments, is lower than the one of the glass yarn, made up of millimetric strands. Losses of strength and ductility were observed between 28 days and a year for the glass yarn-reinforced mortars. For the carbon yarn-reinforced mortars, post-cracking strength increases with time.

Expression and Function of Proteins during Development of the Basal Region in Rice Seedlings

A differential display of proteins with a two-dimensional polyacrylamide gel electrophoresis approach was used to analyze protein expression changes during development of the basal region in rice seedlings (Oryza sativa L. cv. Nipponbare). The proteins were detected as 700 Coomassie Brilliant Blue-stained spots with pI values from around 3.5 to 9.0. A proteome reference map was established for the basal region of two-week-old seedlings. The basal region proteome map was used to analyze quantitative variations in the tissue during development from 2-, 4-, 6-, 8-, and 10-week-old seedlings. During development, 31 proteins were up-regulated, and 30 proteins were down-regulated compared with the 2-week-old basal region proteome map. The main functions of these proteins were primary metabolism and protein synthesis or maintenance. Calreticulin precursor, enolase, and voltage-dependent anion channel were identified among the up- and down-regulated proteins. The twin spots of calreticulin precursor and enolase with different pI values are possibly due to post-translational modifications such as phosphorylation. In addition, seven proteins showed developmental stage-specific expression. All of the developmentally regulated proteins of the basal region were clustered by the S-system, a differential equation that fit to time course of cluster and analyzed for cluster relationships. Proteins with unknown functions were tentatively assigned to functional groups based on cluster relationships. Basal region development proteome data will be valuable for resolving questions in functional genomics. In addition, cluster analysis of the basal region proteome during development will be useful for the assessment of functional proteins.

Evaluation of the 17-kDa Prenyl-binding Protein as a Regulatory Protein for Phototransduction in Retinal Photoreceptors

The mammalian rod photoreceptor phosphodiesterase (PDE6) holoenzyme is isolated in both a membrane-associated and a soluble form. Membrane binding is a consequence of prenylation of PDE6 catalytic subunits, whereas soluble PDE6 is purified with a 17-kDa prenyl-binding protein (PDEdelta) tightly bound. This protein, here termed PrBP/delta, has been hypothesized to reduce activation of PDE6 by transducin, thereby desensitizing the photoresponse. To test the potential role of PrBP/delta in regulating phototransduction, we examined the abundance, localization, and potential binding partners of PrBP/delta in retina and in purified rod outer segment (ROS) suspensions whose physiological and biochemical properties are well characterized. The amphibian homologue of PrBP/delta was cloned and sequenced and found to have 82% amino acid sequence identity with mammalian PrBP/delta. In contrast to bovine ROS, all of the PDE6 in purified frog ROS is membrane-associated. However, addition of recombinant frog PrBP/delta can solubilize PDE6 and prevent its activation by transducin. PrBP/delta also binds other prenylated photoreceptor proteins in vitro, including opsin kinase (GRK1/GRK7) and rab8. Quantitative immunoblot analysis of the PrBP/delta content of purified ROS reveals insufficient amounts of PrBP/delta (<0.1 PrBP/delta per PDE6) to serve as a subunit of PDE6 in either mammalian or amphibian photoreceptors. The immunolocalization of PrBP/delta in frog and bovine retina shows greatest PrBP/delta immunolabeling outside the photoreceptor cell layer. Within photoreceptors, only the inner segments of frog double cones are strongly labeled, whereas bovine photoreceptors reveal more PrBP/delta labeling near the junction of the inner and outer segments (connecting cilium) of photoreceptors. Together, these results rule out PrBP/delta as a PDE6 subunit and implicate PrBP/delta in the transport and membrane targeting of prenylated proteins (including PDE6) from their site of synthesis in the inner segment to their final destination in the outer segment of rods and cones.

Optimization and preliminary characterization of venom isolated from 3 medically important jellyfish: the box (Chironex fleckeri), Irukandji (Carukia barnesi), and blubber (Catostylus mosaicus) jellyfish

To optimize venom extraction and to undertake preliminary biochemical studies of venom from the box jellyfish (Chironex fleckeri), the Irukandji jellyfish (Carukia barnesi), and the blubber jellyfish (Catostylus mosaicus). Lyophilized crude venoms from box jellyfish tentacles and whole Irukandji jellyfish were prepared in water by homogenization, sonication, and rapid freeze thawing. A second technique, consisting of grinding samples with a glass mortar and pestle and using phosphate-buffered saline, was used to prepare crude venom from isolated nematocysts of the box jellyfish, the bells of Irukandji jellyfish, and the oral lobes of blubber jellyfish. Venoms were compared by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot test. Toxicity of some venoms was determined by intravenous median lethal dose assay in mice. Different venom extraction techniques produced significantly different crude venoms for both box and Irukandji jellyfish. Irukandji and blubber venom SDS-PAGE protein profiles were established for the first time. Analysis of Western blot tests revealed that box jellyfish antivenin reacted specifically with the venom of each jellyfish. Toxicity was found in Irukandji jellyfish venom derived by use of the mortar-and-pestle method, but not in the lyophilized venom. Glass mortar-and-pestle grinding and use of an appropriate buffer was found to be a simple and suitable method for the preparation of venom from each jellyfish species studied. This study contributes to biochemical investigations of jellyfish venoms, particularly the venom of the Irukandji jellyfish, for which there are, to our knowledge, no published studies. It also highlights the importance of optimizing venom extraction as the first step toward understanding the complex biological effects of jellyfish venoms.

Stability of rifabutin in two extemporaneously compounded oral liquids.

The stability of rifabutin 20 mg/mL in two oral liquids was studied. Powder from 100 150-mg rifabutin capsules was placed in a glass mortar. Cherry syrup (pH 2.9) or a 1:1 mixture of Ora-Sweet and Ora-Plus (Paddock Laboratories) was added to produce 750 mL of each formulation, which was then stored in 2-oz plastic prescription bottles. Three bottles of each formulation were stored at 4, 25, 30, and 40 degrees C. At 0, 1, 2, 4, 8, and 12 weeks, the bottles were collected and allowed to remain at room temperature for one hour; samples of about 1 mL were collected from each bottle, weighed, and assayed for rifabutin content by high-performance liquid chromatography. The rifabutin liquids prepared with cherry syrup and stored at 4, 25, and 30 degrees C lost a mean of < 8% of the initial drug concentration during the 12-week study; at 40 degrees C, the liquids lost > 10% of the initial drug concentration by 12 weeks. There was a mean loss of < 5% of the initial rifabutin concentration in all the liquids prepared with Ora-Sweet and Ora-Plus. The liquid prepared with cherry syrup, upon standing, showed a tendency for some of the ingredients to float. The suspension prepared with Ora-Sweet and Ora-Plus had a tendency to retain bubbles after it was shaken, but the ingredients did not settle upon standing. Rifabutin 20 mg/mL in two extemporaneously compounded oral liquids prepared from capsules and sweetened vehicles was stable for at least 12 weeks at 4, 25, 30, and 40 degrees C with the exception of rifabutin in cherry syrup, which was stable for only 8 weeks at 40 degrees C.

Preliminary Characterization of Bioreactivity of Novel Carbonaceous Pitches Extracted in N-Methylpyrrolidone

Novel pitches produced by N-methylpyrrolidone (NMP) extraction of coal were evaluated for their biological reactivity in the following bioassays : Salmonella reversion or mutation assay, V79 cell micronucleus assay, medaka larval survival assay, and cytochrome P4501A1 induction, as reflected by ethoxyresorufin O-deethylase activity. The potential health hazards of the NMP-derived extracts were evaluated using a wide spectrum of organisms and assays to determine if fundamental toxicity transcended various species and biological endpoints. The bioassays were also used to characterize partially the chemical nature of biologically reactive compounds in the extracts. The samples tested were unprocessed coal, NMP extracted coal, and NMP-extracted coal following hydrogenation in tetralin at 350, 400, or 450 °C ; conventional Ravenswood coal tar pitch and Koppers coal tar pitch were also evaluated for comparison with the pitches produced by NMP extraction. These samples were pulverized with a glass mortar and pestle and extracted in dimethyl sulfoxide, and the dimethyl sulfoxide extracts were evaluated by bioassay. Elemental analysis was performed on samples, and selected samples were analyzed by gel permeation chromatography and Fourier-transform infrared spectroscopy. Unprocessed and NMP-extracted coal exhibited little, if any, biological reactivity in any of the bioassays. Material hydrogenated at 350 °C was weakly reactive, 400 °C material was moderately reactive in all assays, and 450 °C material was highly reactive in all bioassays, indicating a correlation between biological reactivity and temperature of hydrogenation. In most assays the NMP extracts derived from 450 °C hydrogenated coal exhibited biological reactivity comparable to that of Ravenswood coal tar pitch. Hydrogenation was associated with reduction of number average molecular weight and increased aromaticity of materials. Toxicity of samples correlated well with their ability to induce ethoxyresorufin O-deethylase activity, suggesting polyaromatic hydrocarbons contributed significantly to the biologically reactive chemicals in the extracts. Furthermore, Salmonella reversion assays using tester strains with normal, elevated, or deficient levels of O-acetyltransferase or nitroreductase indicated the mutagenic compounds in NMP extracts of coal hydrogenated at 450 °C were primarily attributed to aromatic amines and that lower amounts of these mutagens were present in samples hydrogenated at or below 400 °C. These findings suggest that NMP-based processing of coal hydrogenated at high temperatures is likely to produce hazardous materials, whereas processing based on hydrogenation at lower temperatures greatly reduces the production of hazardous materials. These findings must be considered in the design of safe pilot or commercial plants.

The beneficial effect of pozzolanas in suppressing the alkali-silica reaction

An investigation has been made of the effect of replacement of part of the ordinary Portland cement (OPC) in an OPC/silica glass (SG) mortar by pulverized fuel ash (PFA), precipitated silica (PS) and ground granulated blastfurnace slag (ggbs). The expansion of the mortar due to alkali-silica reaction is reduced, and it is found in all cases that alkali dilution due to the replacement can play only a minor role in the reduction of expansion. It is hypothesized that a major mechanism of this reduction is an increase in the effective SiO2/Na2O ratio to values in excess of the pessimum value; it is found that the greater is the deviation of this ratio from the pessimum value, the less is the expansion, the order of effectiveness of the replacements being PS &gt; PFA &gt; ggbs. The replacements are more effective in reducing the expansion due to alkali-silica reaction than they are in reducing the loss in bending strength of mortar bars. Observations by transmission electron microscopy of the microstructure of PFA/OPC/SG mortars show that the glass particle surfaces develop a layer of CSH reaction product of lower thickness than that of equivalent mortars without replacement, and that the PFA particles also develop a surface layer of CSH reaction product, but of different morphology to that of glass particle reaction product layers.

Substrate Specificity of Enzymes from Papaya Callus Cultures

Summary Optimal protease activity in extracts of callus cultures of papaya is obtained by triturating lyophilized callus powder with phosphate buffer at pH 6.0 in a glass mortar; addition of reducing agents to the extraction medium does not increase or stabilize enzyme activity. Casein, casein yellow, azocasein and azoalbumin are good substrates for the proteases; little or no acitivity could be measured with hemoglobin, azocoll, hide powder azure and benzoyl-DL-arginine-p-nitroanilide (BAPA) as substrate.

Influence of nitrogen oxides on hydrogen values in the microdetermination of carbon and hydrogen, with an external absorbent

By using an external absorbent for removal of nitrogen oxides it is possible to obtain correct hydrogen values if the whole anhydrone filling of the water-absorption tube is heated at 80–90°C during the combustion. Heating is simply done by providing a normal carbon-hydrogen combustion apparatus with a special glass mortar. The effect of the temperature of the anhydrone filling has been studied as well as the effect of the type of compound.

PLANT GROWTH SUBSTANCES AND THE ACTIVITY OF CELL‐FREE RESPIRATORY ENZYMES

THE HERBICIDAL activity of plant growth substances has been investigated extensively in recent years, but the metabolic basis of herbicidal action remains obscure. The results reported here concern the influence of growth substances on certain respiratory enzymes from bean plants. Parallel studies also have been made in our laboratory on a monocotyledonous plant (Miller and Burris, 1951) to establish whether or not differences exist in their responses that may help to explain the differences in sensitivity to herbicides of diand monocotyledonous plants. An effect upon respiratory enzymes following herbicidal treatment has been suggested by a number of workers. One of the secondary effects of plant growth substances has been described as a depletion of the carbohydrate reserve, which may cause the death of the plant. This response would seem to indicate some change in the respiratory enzymes concerned with carbohydrate metabolism in the plant. Mitchell et al. (1949) have reviewed briefly the literature concerned with the relationship of growth substances and respiratory metabolism of plants. METHODS AND MATERIALS.-Sensation No. 2 yellow wax bean seeds were planted in 10-in. clay pots in pit sand, about twelve seeds per pot. They were supplied at weekly intervals with Hoagland and Arnon's (1938) nutrient solution No. 1 and were watered as necessary with tap water. Threeto 4-week-old plants were used in these experiments. Enzyme preparations having a relatively low rate of respiration without added substrate were made from bean leaves in the following manner: about 20 g. fresh weight of trifoliate leaves from which the petioles had been removed were ground with white silica sand in a glass mortar, and the sap was expressed through a double layer of cheesecloth. The pH of the expressed crude sap was usually 6.2-6.5. The pulp then was reground with 10 ml. of 0.1 M phosphate buffer, pH 8.0, and the liquid again expressed. The sap was adjusted to pH 8.0 with 1 N NaOH and centrifuged for 15 min. at about 560 X G; a better separation of chloroplasts and other cellular debris was obtained by centrifuging the sap at pH 8.0 rather than at pH 6.2-6.5. For certain experiments the centrifuged sediment was worked up with about 10 ml. of 0.1 M phosphate buffer, pif 8.0. These preparations

Action of Mercurial Antiseptics on Muscle Oxydase

While studying the effects of various chemicals and toxins on the activity of freshly prepared muscle oxydase, the authors made some interesting findings regarding the behavior of certain inorganic and organic mercurial antiseptics. A modification of the Thunberg method of determining the decolorization of a standard solution of methylthionine chloride, or methylene blue, in specially constructed glass vacuum tubes was employed. After considerable experimentation the following procedure was found to give the most satisfactory and surprisingly uniform results. Leg and abdominal muscles were carefully dissected from adult white rats, which had been killed by arteriotomy (or cutting of the vessels of the throat), and minced with sharp scissors in a glass mortar. To several grams of this muscle was added an equal number of cubic centimeters of physiological saline. The whole mass was then ground up with clean sand in a porcelain mortar for half an hour and then strained through fine linen. In this way a uniform suspension of minute particles of muscle tissue in muscle juice and saline was obtained. One cubic centimeter of such freshly prepared muscle suspension was introduced with a pipette into a Thunberg tube. Two cubic centimeters of methylene blue solution were then added to the muscle suspension in the tube. This indicator solution was made of 8 parts of methylene blue, 1:2,000, and 6 parts of 0.1 molar solution of acid potassium phosphate. With a Cenco-Hyvac vacuum pump the air was exhausted from the tube, which was then placed in a water bath at 38°C.; and the time required to completely decolorize the solution was carefully measured. The vacuum in the Thunberg tubes was perfectly maintained by carefully greasing the stopcock with a specially prepared lubricant containing a little gutta-percha.

On the magnetic attraction of oxides of iron

Mr. Lane having observed that hardened iron is not so readily attracted by the magnet as soft iron, was proceeding to make some experiments on the subject, when he was led, by Mr. Hatchett’s paper on Magnetical Pyrites, &amp;c., to examine what magnetical properties iron possessed when free from inflammable matter. For this purpose he procured some of the precipitate sold at Apothecaries’ Hall under the name of Ferrum precipitatum , and which is prepared by adding purified kali to a solution of sulphate of iron. This precipitate, the author says, has no magnetic particles; nor, when exposed to a clear red heat, does it acquire any, except when smoke or flame have access to it. The solar heat, when concentrated to the degree at which glass melts, does not render this oxide magnetic, provided it be protected by glass from the dust floating in the air; if not so protected, many of the particles become magnetic. Mr. Lane then rubbed various portions of the oxide, in a glass mortar, with different combustible substances, namely, coal, sulphur, charcoal, camphor, ether, alcohol, &amp;c., but found the oxide was not thereby rendered magnetic, without the assistance of a degree of heat equal to that of melting lead; with that degree, however, it became magnetic. Hydrogen, when aided by a red heat, had the same effect. Charcoal and cinders, well burnt, were found to require a longer continuance of the heat, to have their full effect on the oxide, than dry wood, coal, or sulphur. A single grain of camphor, dissolved in an adequate portion of alcohol, was found sufficient, when assisted by a red heat, to render all the particles of 100 grains of the oxide magnetic. But such substances as are easily sublimed, will, by a continued application even of a low heat, quit the oxide, leaving it, as at first, unmagnetic. Hence we may understand why Prussian blue, sulphurets, and ores of iron, containing inflammable matter, become magnetic by the agency of heat, and revert to their unmagnetic state if the heat is continued long enough to drive off the inflammable matter.