Influência das propriedades de granulados de lactose nas características físicas dos comprimidos

The compaction behavior of powdered solids used in tablets can be dominated by the physical-chemical properties of the excipients because, frequently, they are present in much larger amounts than the drug in tablet formulation. The aim of this study was to evaluate the influence of the size of lactose granules on the physical characteristics of tablets produced in punches of various diameters, since this relation has not been explored in the literature. Granules were produced in several sizes by wet granulation and compressed in punches of different diameters by applying different forces. Size distribution, apparent density and flow of granules were evaluated, as well as the physical characteristics of the tablets (weight, friability, hardness and disintegration time). The results indicate that in situations where excipient characteristics predominate due to low drug content, as in the 7 mm punch, the selection of granule size is important for the mechanical strength of tablet. On the other hand, with the 9, 11 and 13mm punches, it was possible to produce strong tablet from all sizes of granules.

Desenvolvimento de métodos analíticos qualitativos para a análise de darunavir comprimidos

Darunavir is a protease inhibitor used in the treatment of HIV infection. It is a pillar of the drug cocktail for patients diagnosed with the virus. Quality control in the pharmaceutical industry, to verify the content of active substance and study the physicochemical characteristics of the drug, is essential to ensure final product quality. Until now, standardized methods for the analysis of darunavir have not been available in official compendia. This justifies new research, to develop and validate analytical methods, as well as physicochemical and pharmaceutical analysis for this drug, both as a raw material and a finished product. Thus, in this study, (a) the average weight of darunavir tablets and (b) the melting point of the pure drug were determined, and the following analytical techniques were performed: (c) thin-layer chromatography, (d) ultraviolet spectroscopy, (e) infrared spectroscopy and (f) high performance liquid chromatography. By developing the above techniques, it is possible to make a qualitative assessment of the quality of darunavir tablets.

The role of crystalline anisotropy in mechanical property extractions through Berkovich indentation

This work uses crystal plasticity finite element simulations to elucidate the role of elastoplastic anisotropy in instrumented indentation P-h(s) curve measurements in face-centered Cubic (fcc) crystals. It is shown that although the experimental fluctuations in the loading stage of the P-h(s) curves can be attributed to anisotropy, the variability in the unloading stage of the experiments Is much greater than that resulting from anisotropy alone. Moreover, it is found that the conventional procedure used to evaluate the contact variables ruling the unloading P-h(s) curve introduces all uncertainty that approximates to the more fundamental influence of anisotropy. In view of these results, a robust procedure is proposed that uses contact area measurements in addition to the P-h(s) curves to extract homogenized J(2)-Plasticity-equivalent mechanical properties from single crystals.

On the mixing property for a class of states of relativistic quantum fields

Let omega be a factor state on the quasilocal algebra A of observables generated by a relativistic quantum field, which, in addition, satisfies certain regularity conditions [satisfied by ground states and the recently constructed thermal states of the P(phi)(2) theory]. We prove that there exist space- and time-translation invariant states, some of which are arbitrarily close to omega in the weak * topology, for which the time evolution is weakly asymptotically Abelian. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3372623]

The role of oxygen vacancy in the photoluminescence property at room temperature of the CaTiO(3)

In this paper, electron paramagnetic resonance, photoluminescence (PL) emission, and quantum mechanical calculations were used to observe and understand the structural order-disorder of CaTiO(3), paying special attention to the role of oxygen vacancy. The PL phenomenon at room temperature of CaTiO(3) is directly influenced by the presence of oxygen vacancies that yield structural order-disorder. These oxygen vacancies bonded at Ti and/or Ca induce new electronic states inside the band gap. Ordered and disordered CaTiO(3) was obtained by the polymeric precursor method. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3190524]

An alternative to the Pythagorean rule? Reevaluating Problem 1 of cuneiform tablet BM 34 568

The first problem of the Seleucid mathematical cuneiform tablet BM 34 568 calculates the diagonal of a rectangle from its sides without resorting to the Pythagorean rule. For this reason, it has been a source of discussion among specialists ever since its first publication. but so far no consensus in relation to its mathematical meaning has been attained. This paper presents two new interpretations of the scribe`s procedure. based on the assumption that he was able to reduce the problem to a standard Mesopotamian question about reciprocal numbers. These new interpretations are then linked to interpretations of the Old Babylonian tablet Plimpton 322 and to the presence of Pythagorean triples in the contexts of Old Babylonian and Hellenistic mathematics. (C) 2007 Elsevier Inc. All rights reserved.

Dissolution parameters for sodium diclofenac-containing hypromellose matrix tablet

Sodium diclofenac (SD) release from dosage forms has been studied under different conditions. However, no dissolution method that is discriminatory enough to reflect slight changes in formulation or manufacturing process, and which could be effectively correlated with the biological properties of the dosage form, has been reported. This study sought to develop three different formulae of SD-containing matrix tablets and to determine the effect of agitation speed in its dissolution profiles. F1, F2 and F3 formulations were developed using hypromellose (10, 20 and 30%, respectively for F1, F2 and F3) and other conventional excipients. Dissolution tests were carried out in phosphate buffer pH 6.8 at 37 degrees C using apparatus 11 at 50, 75 or 100 rpm. Dissolution efficiency (DE), T(50) and T(90) were determined and plotted as functions of the variables agitation speed and hypromellose concentration. Regarding DE, F2 showed more sensitivity to variations in agitation speed than F1 and F3. Increasing hypromellose concentration reduced DE values, independent of agitation speed. Analysis of T(50) and T(90) suggests that F1 is less sensitive to variations in agitation speed than F2 and F3. Most discriminatory dissolution conditions were observed at 50 rpm. Results suggest that the comparison of dissolution performance of SD matrix tablets should take into account polymer concentration and agitation conditions. (C) 2009 Published by Elsevier B.V.

Bioequivalence assay between orally disintegrating and conventional tablet formulations in healthy volunteers

The purpose of this study was to evaluate bioequivalence of two commercial 8 mg tablet formulations of ondansetrona available ill the Brazilian market. In this study, a simple, rapid, sensitive and selective liquid chromarography-tandem mass spectrometry method is described for the determination of ondansetron in human plasma samples. The method was validated over a concentration range of 2.5-60 ng/ml and used in a bioequivalence trial between orally disintegrating and conventional tablet ondansetron formulations, to assess its usefulness in this kind of Study. Vonau flash (R) (Biolab Sanus Farmaceutica, Brazil, as test formulations) and Zofran (R) (GlaxoSmithKline, Brazil, as reference formulation) were evaluated following a single 8 mg close to 23 healthy volunteers of both genders. The dose was administered after an overnight fast according to a two-way crossover design. Bioequivalence between the products was determinated by Calculating 90% confidence interval (90% CI) for the ratio of C(max), AUC(0-t) and AUC(0-(sic)) values for the test and reference products, using logarithmically transformed data. The 90% confidence interval for the ratio of C(max) (87.5-103.8%), AUC(0-t) (89.3-107.2%) and AUC(0--(sic)) (89.7-106.0%) values for the test and reference products is Within the 80-125% interval, proposed by FDA, EMEA and ANVISA. It was concluded that two ondansetron formulations are bioequivalent ill their rate and extent of absorption. (C) 2008 Elsevier B.V. All rights reserved.

Bioequivalence Evaluation of Two Different Tablet Formulations of Tinidazole in Healthy Volunteers

The bioequivalence of two different tablet formulations of tirtidazole (CAS 19387-91-8) was determined in healthy volunteers after a single dose in a randomized crossover study, with a 1-week washout period between the doses. Reference and test products were administered to 24 volunteers with 240 mL water after overnight fasting. Plasma concentrations of tinidazole were monitored by a high-performance liquid chromatographic method (HPLC) over a period of 72 h after the administration. The pharmacokinetic parameters AUC(0-t), AUC(0-infinity), C(max), T(max), T((1/2)el) and beta were determined from plasma concentration time profile of both formulations and found to be in good agreement with previously reported values. The calculated pharmacokinetic parameters were compared statistically to evaluate bioequivalence between the two brands. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals for the ratio of C(max) (93.9 - 102.6%), AUC(0-t), (94.9-101.1%) and AUC(0-infinity) (94.6-100.8%) values for the test and reference products were within the 80 - 125% interval, satisfying bioequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration Guidelines. These results indicate that the test and the reference products of tinidazole are bioequivalent and, thus, may be prescribed interchangeably.

How thick is thick? Multicenter study of the rheological and material property characteristics of mealtime fluids and videofluoroscopy fluids

Objective rheological assessment of fluids given to dysphagic patients at mealtime and during videofluoroscopy was carried out using a multicenter format. Thin, quarter-thick, half-thick and full-thick fluids were examined for the degree of correlation between mealtime fluids and their allegedly matched videofluoroscopy counterparts. The study was carried out to determine whether perceived subjective differences between mealtime fluids and videofluoroscopy fluids could be quantified using the rheological parameters of viscosity, density, and yield stress. The results showed poor correlation between mealtime fluids and videofluoroscopy fluids over all parameters. In general, the videofluoroscopy fluids were more viscous, more dense, and showed higher yield stress values than their mealtime counterparts. Given these results, it is reasonable to assume that the fluids used during videofluoroscopy do not provide an accurate indication of swallowing ability at mealtime. Therefore, it is suggested that clinicians use objective methods to theologically match videofluoroscopy fluids to mealtime fluids.

Property crime and income generation by heroin users

This paper provides a detailed analysis of patterns of income generation among 202 active heroin users in South West Sydney. We explore both sources of income and the relative contribution of different types of income generating activities, including drug sales and related activities, property crime, prostitution, legitimate income and avoided expenditures. Despite claims that heroin use leads inevitably to property crime, drug market activities accounted for a greater proportion of drug user income in this sample. Results indicate that law enforcement crackdowns that reduce opportunities for generating income from the drug market may increase property crime by heroin users.

Stability property of matchings is a natural solution concept in coalitional market games

Stability of matchings was proved to be a new cooperative equilibrium concept in Sotomayor (Dynamics and equilibrium: essays in honor to D. Gale, 1992). That paper introduces the innovation of treating as multi-dimensional the payoff of a player with a quota greater than one. This is done for the many-to-many matching model with additively separable utilities, for which the stability concept is defined. It is then proved, via linear programming, that the set of stable outcomes is nonempty and it may be strictly bigger than the set of dual solutions and strictly smaller than the core. The present paper defines a general concept of stability and shows that this concept is a natural solution concept, stronger than the core concept, for a much more general coalitional game than a matching game. Instead of mutual agreements inside partnerships, the players are allowed to make collective agreements inside coalitions of any size and to distribute his labor among them. A collective agreement determines the level of labor at which the coalition operates and the division, among its members, of the income generated by the coalition. An allocation specifies a set of collective agreements for each player.