SOLID-STATE STABILITY AND SOLUBILITY DETERMINATION OF CRYSTALLINE FORMS OF MOXIFLOXACIN HYDROCHLORIDE

Objective: This study aims to evaluate possible crystalline changes that can occur with MOX under the influence of temperature and relative humidity (RH) as well as to determine the relative solubility of the observed crystalline forms.Methods: Thermoanalytical methods with the support of non-thermal analysis such as X-ray powder diffraction and infrared spectroscopy were used for testing structural changes of Moxifloxacin hydrochloride (MOX) stored under four different conditions. Additionally, relative solubilities of the observed crystalline forms were determined by the shake-flask method.Results: After storage for 1 mo at 0 % relative humidity (RH) and 40 % RH, MOX remained with crystal structure unchanged and shown to have a good physical stability at these conditions. However, when the drug was stocked for 1 mo at 90 % RH and 75 %, a hydrated crystalline form was identified in both conditions. In the solubility assay, it was observed that the hydrated form is less soluble that initial MOX.Conclusion: Pharmacotechnical wet processes are not be recommended for the pharmaceutical production of this drug because solvent granulation and drying conditions from processing provides a favorable environment for the transition of crystalline forms. According to DSC, TG, PXRD, HPLC and FT-IR results, they showed good correlation with each other and ensure reliable interpretation of solid form stability studies. Moreover, these findings suggest that stability studies of a polymorphism associated with the evaluation of relative solubility are essential for a stable formulation development and to choose between dry or wet granulation processes.Â

Determinação não destrutiva do nitrogênio total em plantas por espectroscopia de reflectância difusa no infravermelho próximo

Diffuse reflectance near-infrared (DR-NIR) spectroscopy associated with partial least squares (PLS) multivariate calibration is proposed for a direct, non-destructive, determination of total nitrogen in wheat leaves. The procedure was developed for an Analytical Instrumental Analysis course, carried out at the Institute of Chemistry of the State University of Campinas. The DR-NIR results are in good agreement with those obtained by the Kjeldhal standard procedure, with a relative error of less than ± 3% and the method may be used for teaching purposes as well as for routine analysis

Química Analítica de Processos

Process Analytical Chemistry (PAC) is an important and growing area in analytical chemistry, that has received little attention in academic centers devoted to the gathering of knowledge and to optimization of chemical processes. PAC is an area devoted to optimization and knowledge acquisition of chemical processes, to reducing costs and wastes and to making an important contribution to sustainable development. The main aim of this review is to present to the Brazilian community the development and state of the art of PAC, discussing concepts, analytical techniques currently employed in the industry and some applications

Development and Validation of a Chromatography Method Using Tandem UV/Charged Aerosol Detector for Simultaneous Determination of Amlodipine Besylate and Olmesartan Medoxomil: Application to Drug-Excipient Compatibility Study

A study was carried out to investigate compatibility of amlodipine besylate and olmesartan medoxomil with a variety of pharmaceutical excipients. Both drugs are antihypertensive agents that can be administered alone, in monotherapy, or in pharmaceutical association. The studies were performed using binary and ternary mixtures, and samples were stored for 3 and 6 months at 40°C under 75% relative humidity and dry conditions. For this study, a method based on high-performance liquid chromatography (HPLC) was developed and validated for the simultaneous determination of amlodipine besylate and olmesartan medoxomil in samples from pharmaceutical preformulation studies using diode array detector (DAD) and charged aerosol detector (CAD). The runtime per sample was 10 min with retention time of 7.926 min and 4.408 min for amlodipine and olmesartan, respectively. The validation was performed according to ICH guidelines. The calibration curve presents linear dynamic range from 12 to 250 μg mL−1 for amlodipine and from 25 to 500 μg mL−1 for olmesartan with coefficient of determination (R2 ≥ 0.9908) while repeatability and reproducibility (expressed as relative standard deviation) were lower than 1.0%. The excipients such as corn starch, croscarmellose sodium, magnesium stearate, polyvinyl alcohol, talc, polyvinylpyrrolidone, lactose monohydrate, and polyethylene glycol showed potential incompatibilities after accelerated stability testing

Non-destructive determination of total nitrogen in plants by diffuse reflectance near infrared spectroscopy

Diffuse reflectance near-infrared (DR-NIR) spectroscopy associated with partial least squares (PLS) multivariate calibration is proposed for a direct, non-destructive, determination of total nitrogen in wheat leaves. The procedure was developed for an Analytical Instrumental Analysis course, carried out at the Institute of Chemistry of the State University of Campinas. The DR-NIR results are in good agreement with those obtained by the Kjeldhal standard procedure, with a relative error of less than ± 3% and the method may be used for teaching purposes as well as for routine analysis.700703Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES