LC-DAD Determination of Fleroxacin in Bulk and Pharmaceutical Dosage Forms

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Propolis Standardized Extract (EPP-AF (R)), an Innovative Chemically and Biologically Reproducible Pharmaceutical Compound for Treating Wounds

The aim of this study was to develop a formulation, containing the propolis standardized extract (EPP-AF (R)), which can assist in the healing of skin lesions. To achieve this objective the antimicrobial activity and chemical composition of the propolis extract was determined. The final product was subjected to in vitro and in vivo pre-clinical evaluation. The broth macrodi-lution method was used to determine the antimicrobial activity of the extracts and formulations against the microorganisms most commonly found in burns, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus and Staphylococcus epidermidis. Wistar rats with puncture wounded skin were used to evaluate the wound healing properties of propolis. The results of chemical and biological characterization demonstrated the batch-to-batch reproducibility of the standardized extract which is an unprecedented result. The antimicrobial and wound healing activity of the pharmaceutical studied showed the best results when samples contain 3.6% propolis, suggesting that this is the most promising composition.

Situacao atual da quimioterapia contra a tuberculose

Actions to overcome a disease are dependant, essentially, on what is known about it. Procedures followed in the past were sometimes bizarre, but justified because of how little was known about the disease. The tuberculosis prechemotherapeutic age was somber due to the high levels of fatalities and morbidity. With the arrival of the chemotherapeutic treatment its prognosis has changed. Tuberculosis declined in the 50's and stabilized in the 80's. Nevertheless, it is back increasing alarming its numbers more than ever; probably because of some factors, among them, the public health system lack of attention and the government's policies, increasing in the migration to and from the endemic areas, development of drug multi-resistant cepa and also to the HIV infection. An universal antimycobacteria chemotherapy treatment is not accepted, maybe because of the number of drugs that are available. Modern chemotherapy, however, has an attack and a maintenance phases with the aim to eliminate the bacillus of fast and slow multiplication, respectively. The treatment period is long, when compared with other infectious diseases, that leads to the lack of compliance. In spite of the available resources in the fight against tuberculosis they seem insufficient to restrain the disease. This has forced the search for new chemotherapy alternatives to avoid strong come back of tuberculosis to the point of being called the 'white plague' well into the 21'st century.

Non-aqueous Titration of Gatifloxacin in Pharmaceutical Formulations using Perchloric Acid

An inexpensive, simple, precise and rapid method for the determination of fluoroquinolone gatifloxacin in tablets is described. The procedure is based on the use of volumetric dosage in a non-aqueous medium in glacial acetic acid with 0.1 M perchloric acid. The method validation yielded good results and included the precision, recovery and accuracy. It was also found that the excipients in the commercial tablet preparation did not interfere with the assay.

Spectrophotometric determination of methyldopa in pharmaceutical formulations

A new, simple, precise, rapid and low-cost spectrophotometric method for methyldopa determination in pharmaceutical preparations is described. This method is based on the complexation reaction of methyldopa with molybdate. Absorbance of the resulting yellow coloured product is measured at 410 nm. Beer's Law is obeyed in a concentration range of 50 - 200 μg ml -1 methyldopa with an excellent correlation coefficient (r = 0.9999). No interference was observed from common excipients in formulations. The results show a simple, accurate, fast and readily applied method to the determination of methyldopa in pharmaceutical products. The analytical results obtained for these products by the proposed method are in agreement with those of the Brazilian Pharmacopoeia procedure at 95% confidence level.

Validation of UV spectrophotometric method for determination of lomefloxacin in pharmaceutical dosage form

A simple and reproducible method was developed for the assay of lomefloxacin in tablets. The excipients in the commercial tablet preparation did not interfere with the assay. Beer's law is obeyed in the range 2.0-9.0 μg.mL-1 at λmax 280 nm. The molar absorptivity was calculated. Six triplicate analyses of solutions containing six different concentrations of the examined drug were carried out and gave a mean correlation coefficient 0.9997. The proposed method was applied to the determination of the examined drug in coated tablet and the results demonstrated that the method is equally accurate, precise and reproducible as the official methods.

Magnetic images of pharmaceutical dosage forms in the human gastrointestinal tract

Oral administration with solid dosage forms is a common route in the drug therapy widely used. The drug release by the disintegration process occurs in several gastrointestinal tract (GIT) regions. AC Biosusceptometry (ACB) was originally proposal to characterize the disintegration process of tablets in vitro and in the human stomach, through changes in magnetic signals. The aim of this work was to employ a multisensor ACB system to monitoring magnetic tablets and capsules in the human GIT and to obtain the magnetic images of the disintegration process. The ACB showed accuracy to quantify the gastric residence time, the intestinal transit time and the magnetic images allowed to visualize the disintegration of magnetic formulations in the GIT. The ACB is a non-invasive, radiation free technique, completely safe and harmless to the volunteers and had demonstrated potential to evaluate pharmaceutical dosage forms in the human gastrointestinal tract. © 2005 IEEE.

Determination of methyldopa in pharmaceutical formulations by combined spot test-diffuse reflectance spectroscopy

This paper describes a very simple and rapid quantitative reflectance spot test procedure for the determination of methyldopa in pharmaceutical formulations. This method is based on the complexation reaction of methyldopa with molybdate ions yielding a yellow stable complex on filter paper. Reflectance measurements were carried out at 410 nm. Under optimal conditions, the calibration graphs obtained for methyldopa by plotting the optical density of the reflectance signal (A R) vs. the log of the concentration were linear from 6.30 × 10 -3 to 1.89 × 10 -2 mol L -1, with a correlation coefficient of 0.998. The detection limit was 2.74 × 10 -3 mol L -1 (R.S.D. = 1.02%) for methyldopa. The common excipients used as additives in pharmaceuticals do not interfere in the proposed method. The method was applied to determine metyldopa in commercial pharmaceutical formulations. The results obtained by the proposed method compare favorably with those obtained by an official procedure at 95% confidence level. ©2006 Sociedade Brasileira de Química.

Thermoanalytical study of praziquantel-loaded PLGA nanoparticles

Polymeric nanoparticles have received great attention as potential controlled drug delivery systems. Biodegradable polymers has been extensively used in the development of these drug carriers, and the polyesters such as polylactic acid, polyglycolic acid and their copolymers as poly-lactide-co- glycolide are the most used, considering its biocompatibility and biodegradability. Thermal analysis techniques have been used for pharmaceutical substances for more than 30 years and are routine methods for screening drug-excipient interactions. The aim of this work is to use thermal analysis to characterize PLGA nanoparticles containing a hydrophobic drug, praziquantel. The results show that the drug is in an amorphous state or in disordered crystalline phase of molecular dispersion in the PLGA polymeric matrix and that the microencapsulation process did not interfere with the chemical structure of the polymer, mantaining the structural drug integrity.

A new insight about pharmaceutical dosage forms for benzathine penicillin G

In this work, a micellar system of benzathine penicillin G (BPG) in sodium deoxycholate (NaDC) was developed and evaluated physicochemically. The solubility profile of the drug in water and buffer solutions at various pH was determined, as well as its n-octanol/water partition coefficient. The Critical Micellar Concentration of NaDC and its ability to incorporate BPG were also assessed. The study was carried out at low and high ionic strength which was adjusted by the addition of sodium chloride. The results demonstrated the ability of the micellar system to incorporate BPG, as well as to increase its apparent solubility in water. The enhancement of the solubility of BPG by the presence of NaDC micelles could be analyzed quantitatively within the framework of the pseudo-phase model. Concentration analysis showed that the micellar system could attain up to 90% incorporation of BPG. The incorporated drug is expected to exhibit improved stability, since the antibiotic enclosed in the hydrophobic core of micelles is rather shielded from the aqueous external environment.

A simplified reflectometric method for the rapid determination of dipyrone in pharmaceutical formulations

This paper describes a simple, portable and environmentally friendly method for the rapid determination of dipyrone in pharmaceuticals by using diffuse reflectance spectroscopy. The proposed method is based on the reflectance measurements of the orange compound produced from the spot test reaction between dipyrone and p-dimethylaminocinnamaldehyde (p-DAC), in acid medium, using a filter paper as solid support. Experimental design methodologies were used to optimize the measurement conditions. All reflectance measurements were carried out at 510 nm and the linear range was from 1.42 × 10-4-2.85 × 10-3 mol L-1, with a correlation coefficient of 0.999. The limit of detection (LOD) and the limit of quantification (LOQ) were 1.20 × 10-5 mol L-1 and 4.00 × 10-5 mol L-1, respectively. The intraday precision and interday precision were studied for 10 replicate analyses of 7.90 × 10-4 mol L-1 dipyrone solution. The coefficients of variation were 1.1 and 0.9%, respectively. The proposed method was applied successfully to the determination of dipyrone in commercial brands of pharmaceuticals. No interferences were observed from the common excipients in formulations. The results obtained by the proposed method were favorably compared with those given by the Brazilian Pharmacopoeia procedure at 95% confidence level. ©2007 Sociedade Brasileira de Química.

A proposed behavioral tool to assess sustained auditory attention

Sustained attention and vigilance are processeses that characterize attention, and are essential for the development of certain abilities Aim: a prospective study to propose a simple, easy and quick behavioral tool to support the assessment of sustained auditory attention. Material and methods: volunteer children aged between 6 and 11 years (139 female and 141 male) were selected. The test was named Sustained Auditory Attention Ability Test, and is based on the Continuous Performance Test. It consist of a binaural and diotic presentation of a list of 100 monosyllabic words in which a target monosyllable is included 20 times. This list was presented six times with no breaks. The test was carried out in a soundproofed room, using a CD player attached to a two-channel audiometer at 50 dBSL during 9 minutes. The test resulted in a total score and a vigilance decrement. Results: There was no statistically significant difference between genders, but a significant difference was found between ages. Conclusion: The proposed test had no discomfort for the participants, and was shown to be extremely promising to assess the sustained auditory attention ability in children. © Revista Brasileira de Otorrinolaringologia. All Rights reserved.

Determination of atenolol in pharmaceutical formulations by diffuse reflectance spectroscopy

A simple analytical method for quantification of atenolol in pharmaceutical formulations by diffuse reflectance spectroscopy is described. The method is based on the reaction, on the filter paper surface, between the drug and p-chloranil producing a colored compound. The best reaction conditions were obtained with 20 μL of atenolol solution and 20 μL of p-chloranil. All reflectance measurements were carried out at 550 nm and the linear range was from 1.13×10-2 to 7.88×10-2 mol L-1 (r = 0.9992). The limit of detection was 2.80 × 10-3 mol L-1. The proposed method was successfully applied to analysis of different commercial brands of pharmaceutical formulations and the results obtained by the proposed method were in good agreement with those obtained using the British Pharmacopoeia method.

Non-conventional applications of computerized tomography: Analysis of solid dosage forms produced by pharmaceutical industry

X-ray computed tomography (CT) refers to the cross-sectional imaging of an object measuring the transmitted radiation at different directions. In this work, we describe a non-conventional application of computerized tomography: visualization and improvements in the understanding of some internal structural features of solid dosage forms. A micro-CT X-ray scanner, with a minimum resolution of 30 μm was used to characterize some pharmaceutical tablets, granules, controlled-release osmotic tablet and liquid-filled soft-gelatin capsules. The analysis presented in this work are essentially qualitative, but quantitative parameters, such as porosity, density distribution, tablets dimensions, etc. could also be obtained using the related CT techniques. © 2010 American Institute of Physics.