Synthesis and characterization of carboxymethyl starch-g-polyacrylic acids and their properties as adsorbents for ammonia and phenol.

Cigarette smoke contains a lot of harmful chemicals which cause different diseases like cancer, heart disease, bronchitis and ulcer etc. Ammonia and phenol are among those chemicals which cause cancer, fibrosis, respiratory disorder and pneumonia. So, to remove ammonia and phenol from cigarette smoke, five different types of carboxymethyl starch-g-polyacrylic acids (CMS-g-PAAs) were synthesized by using different initiators, different mole ratio of acrylic acid to CMS anhydroglucose unit (AGU) and different amount of water. Three types of modified CMSs, CMS-g-PAA1, CMS-g-PAA3 and CMS-g-PAA4 were selected for further characterization and application for ammonia and phenol adsorption. The 1H NMR and FT-IR spectroscopy confirmed the successful grafting of PAA on CMS. Crystallinity of CMS and three modified CMSs was checked by their XRD analysis. The XRD analysis showed that CMS had crystalline nature which was lost after modification. The thermal properties of CMS and the modified samples were checked by TGA and DTG which also gave information about the successful grafting on PAA on CMS. Finally the modified CMSs were further used for the adsorption applications of ammonia and phenol from the gaseous stream. It was found that CMS-g-PAA4 showed the highest adsorption efficiency towards ammonia (0.352 mmol/g) and phenol (0.18 mmol/g).

Iodine-Starch test for assessment of hyperhidrosis in amputees, evaluation of different methods of application.

PURPOSE: Hyperhidrosis is a common problem for amputees. The iodine-starch test is frequently used to assess hyperhidrosis, but a method for its application has not been described for amputees. METHODS: We performed an unblinded comparison of the iodine-starch test using various methods to protect the prosthesis in 10 prosthetic limb users with hyperhidrosis. RESULTS: Plastic wrap produced a diffuse pattern of sweating in 70% of subjects. Forty percent had complaints about this method, and 50% experienced leakage of iodine stain onto prosthetic liners. The prosthetic sheath produced a focal or multifocal reaction in 100% of subjects after 10 min of ambulation. Eighty percent had minor leakage onto the liner, and complaints were noted in 10%. The proportion that experienced diffuse sweating was significantly higher in the plastic wrap condition (p = 0.016; difference in proportions = 70%; 95% confidence interval = 32-100%). The prosthetic sock was tested in four subjects and all had at least mild complaints; three had minor leakage onto the liner. Repeated complaints and lack of stain prevention led to discontinuation with this method. CONCLUSIONS: Of the three methods, the sheath produces a focal or multifocal reaction after 10 min of ambulation and tends to cause less subject complaints. It should be the preferred method to apply the iodine-starch test to amputees. Implications for rehabilitation Hyperhidrosis is a common problem in amputees which negatively affects quality of life. The iodine-starch test is commonly used to guide treatment decisions for hyperhidrosis, but a preferred method for applying it in amputees has not been described. This study describes different methods for applying the iodine-starch test. A prosthetic sheath covering should be the preferred method for the iodine-starch test in amputees.

A new apparatus for real-time assessment of the particle size distribution of disintegrating tablets.

The aim of this study is the introduction of a novel apparatus that is capable of continuously measuring the particle size reduction of disintegrating tablets and analysis of the obtained results. The apparatus is constructed such that no particles pass directly through the pumping system. Thereby, the overall energy input into the particle suspension is reduced, and continuous measurement is possible without rapid destruction of the generated particles. The detected particle sizes at the beginning and at the end of the measurement differ greatly, depending on the applied disintegrant. The median particle sizes at the end of the measurement vary between 621.5 and 178.0 µm for different disintegrants. It is demonstrated that the particle size reduction follows an exponential function and that the fit parameters can be used to describe the disintegration behavior. A strong correlation between the median particle size of crospovidone disintegrants and generated particle size of the tablets is observed. This could be due to a more homogeneous distribution of the disintegrant particles in the tablets. Similar trends are observed for sodium starch glycolate and croscarmellose sodium. The new apparatus provides an innovative method to describe disintegrant effectiveness and efficiency.

Assessment of disintegrant efficacy with fractal dimensions from real-time MRI.

An efficient disintegrant is capable of breaking up a tablet in the smallest possible particles in the shortest time. Until now, comparative data on the efficacy of different disintegrants is based on dissolution studies or the disintegration time. Extending these approaches, this study introduces a method, which defines the evolution of fractal dimensions of tablets as surrogate parameter for the available surface area. Fractal dimensions are a measure for the tortuosity of a line, in this case the upper surface of a disintegrating tablet. High-resolution real-time MRI was used to record videos of disintegrating tablets. The acquired video images were processed to depict the upper surface of the tablets and a box-counting algorithm was used to estimate the fractal dimensions. The influence of six different disintegrants, of different relative tablet density, and increasing disintegrant concentration was investigated to evaluate the performance of the novel method. Changing relative densities hardly affect the progression of fractal dimensions, whereas an increase in disintegrant concentration causes increasing fractal dimensions during disintegration, which are also reached quicker. Different disintegrants display only minor differences in the maximal fractal dimension, yet the kinetic in which the maximum is reached allows a differentiation and classification of disintegrants.

Functional assessment of four types of disintegrants and their effect on the spironolactone release properties.

Spironolactone is a drug derived from sterols that exhibits an incomplete oral absorption due to its low water solubility and slow dissolution rate. In this study, formulations of spironolactone with four disintegrants named as croscarmellose sodium, crospovidone, sodium starch glycolate and microcrystalline cellulose II (MCCII) were conducted. The effect of those disintegrants on the tensile strength, disintegration time and dissolution rate of spironolactone-based compacts was evaluated using a factorial design with three categorical factors (filler, lubricant, and disintegrant). The swelling values, water uptake and water sorption studies of these disintegrants all suggested that MCCII compacts disintegrate by a wicking mechanism similar to that of crospovidone, whereas a swelling mechanism was dominant for sodium starch glycolate and croscarmellose sodium. The disintegration time of MCCII and sodium starch glycolate remained unchanged with magnesium stearate. However, this lubricant delayed the disintegration time of crospovidone and croscarmellose sodium. MCCII presented the fastest disintegration time independent of the medium and lubricant employed. The water sorption ratio and swelling values determined sodium starch glycolate followed by croscarmellose sodium as the largest swelling materials, whereas crospovidone and MCCII where the least swelling disintegrants. The swelling property of sodium starch glycolate and croscarmellose sodium was strongly affected by the medium pH. The disintegration time of spironolactone compacts was faster when starch was used as a filler due to the formation of soft compacts. In this case, the type of filler employed rather than the disintegrant had a major effect on the disintegration and dissolution times of spironolactone.

Fast assessment of the surface distribution of API and excipients in tablets using NIR-hyperspectral imaging.

The inclusion of hyperspectral imaging systems in the manufacturing and development of pharmaceutical products is allowing a successful improvement in the quality control of solid dosage forms. The correct distribution not only of active pharmaceutical ingredient (API) but also of the rest of excipients is essential to assure the correct behavior of the tablet when ingested. This is especially relevant in tablets with low content of potent APIs, in which the prescribed intake dosage frequently corresponds to half-a-tablet. Therefore, the aim of this work is to study the surface distribution of the compounds in tablets with low API content. The proposed procedure includes the scanning of the tablet surface using near infrared hyperspectral spectroscopy in association with multivariate curve resolution (MCR) techniques to obtain selective pictures for each individual compound and to allow the fast assessment of their distribution in the measured surface. As an example, a set of commercial Lorazepam tablets (approximately 1% mass fraction of API, and four excipients) were analyzed. The results obtained show the capacity of the proposed methodology as an expedite approach to evaluate the uniformity of the contents between and within tablets. A method to estimate the homogeneity distribution of API in the two halves of the tablet is also proposed.

Harvesting the noncirculating pool of polymorphonuclear leukocytes in rats by hetastarch exchange transfusion (HET): yield and functional assessment.

Isolation of polymorphonuclear leukocytes (PMN) provides an opportunity to study PMN activity in vitro and to label PMN for study of in vivo kinetics. However, simple phlebotomy (SP) of a small animal frequently yields too few PMN for in vitro handling, while PMN harvested from an induced-peritonitis may not accurately reflect PMN in a less stimulated state. We report a novel method of harvesting PMN from the circulation of rats, using hetastarch exchange transfusion (HET), which is both time and animal sparing. HET harvested 8-fold more PMN than SP. In vitro cell function was examined with assays of adherence, chemotaxis, bacterial killing, and superoxide generation. No significant (p less than 0.05) difference was found between PMN obtained by HET and pooled-PMN obtained by SP. In vivo function was examined following labeling with indium111-oxine. The kinetics pattern described suggested normal migratory activity when compared to previous reports. The data demonstrate that rats possess a relatively large, noncirculating pool of PMN which is readily accessible by HET.

Platelet inhibitors and hydroxyethyl starch: safe and cost-effective interventions in coronary artery surgery.

This study evaluated the cost-effectiveness and clinical safety of utilizing hetastarch in pump prime solutions and for colloid replacement postoperatively in conjunction with the platelet inhibitors, aspirin and Persantine (dipyridamole). Sixty-four adult patients undergoing a coronary artery bypass operation were divided into two groups. Group 1 (N = 32) received only Persantine (75 mg three times a day) on the day prior to operation. Group 2 (N = 32) received the same Persantine dose plus aspirin (325 mg). In both groups, aspirin and Persantine were continued postoperatively and hetastarch was used as the colloid of choice. All patients were evaluated for blood loss, coagulation profiles, cost of blood and colloid replacement, and clinical course. Group 2 patients demonstrated significantly greater blood loss (p less than 0.05) but the same postoperative coagulation profiles as Group 1. The transfusion requirement (3.6 units versus 1.3 units) and cost basis ($252 versus $91) for patient care were higher in Group 2. Hetastarch had no effect on blood loss and was not associated with any adverse clinical reactions. Annual institutional savings based on utilization of hetastarch were calculated at $33,500 to $40,500 per 500 patients. We conclude that preoperative administration of aspirin (325 mg) is associated with increased perioperative blood loss and higher patient costs, two variables not demonstrable with Persantine only. Use of hetastarch combined with postoperative platelet inhibition was clinically safe and was a cost-effective method of colloid replacement.

Cost savings from hetastarch use in place of albumin on a cardiothoracic surgery service.

The use of hetastarch in 38 cardiothoracic surgery patients was monitored prospectively to determine patient parameters that influence physicians' prescribing practices. Potential cost savings from substituting hetastarch for albumin were calculated and use of hetastarch, following introduction to the hospital, was monitored. Data were statistically analyzed, and no correlation was seen among operative procedure, type of admission (transfer or direct admission), or patient age. During the 2-month study period, $800 was saved on the cardiothoracic surgery unit by substituting hetastarch for 5% albumin. An additional $1,600 could have been saved if optimal amounts of hetastarch had been used. Substitution of hetastarch for 5% albumin on just one intensive care unit in this 283-bed hospital is projected to elicit annual cost savings of $14,000.

Hetastarch as a prime for cardiopulmonary bypass.

Hetastarch, a synthetic colloid osmotic plasma volume expander, was employed in a prime for cardiopulmonary bypass in 37 patients undergoing myocardial revascularization. Comparison of laboratory values to those of 42 patients undergoing myocardial revascularization using an albumin-containing prime showed lower postoperative platelet counts (p less than 0.02) with hetastarch. There were no differences in chest tube drainage, blood use, plasma hemoglobin, fibrinogen levels, of coagulation times. The hetastarch prime cost $119.50 per patient, whereas the albumin-containing prime cost $321.35 per patient.