Fábio S. Murakami

Physicochemical study of CaCO3 from egg shells

O carbonato de calcio e um excipiente farmaceutico amplamente utilizado como diluente em formas farmaceuticas solidas. Tambem e utilizado para auxiliar na dissolucao de comprimidos dispersiveis, como base para preparacoes dentais e medicinais, e como aditivos em suplementos alimentares. A casca de ovo e rica em sais minerais, principalmente o carbonato de calcio que corresponde a 94% da casca. As industrias de ovos produzem grande quantidade de casca e seu destino final e um desafio em termos ambientais. Este trabalho teve como objetivo avaliar as propriedades fisico-quimicas do carbonato de calcio obtido a partir da casca de ovo. Os resultados demonstraram que o carbonato de calcio obtido pode ser uma alternativa como excipiente farmaceutico.

Development and Validation of a RP‐HPLC Method to Quantify Omeprazole in Delayed Release Tablets

Abstract An analytical method using a sensitive high performance liquid chromatographic technique was developed to quantify omeprazole in delayed release tablets. The analysis was carried out using a RP‐C18 column with UV‐Vis detection at 280 nm. The mobile phase was diluted with phosphate buffer (pH 7.4) and acetonitrile (70:30 v/v) at a flow‐rate of 1.5 mL·min−1. The parameters used in the validation process were: linearity, range, quantification limit, accuracy, specificity, and precision. The retention time of omeprazole was about 5 min with symmetrical peaks. The linearity in the range of 10.0–30.0 µg/mL presented a correlation coefficient of 0.9995. The excipients in the formulation did not interfere with the analysis and the recovery was quantitative. Results were satisfactory and the method proved to be adequate for quality control of omeprazole delayed release tablets.

Physico-chemical solid-state characterization of omeprazole sodium: thermal, spectroscopic and crystallinity studies.

The physical characterization of active pharmaceutical substances is crucial to the successful development of the final drug product. The different solid forms and variations in the degree of crystallinity can lead to significantly different physical and chemical properties, including color, morphology, stability, dissolution and bioavailability. In the case of omeprazole sodium (OMS), its chemical structures contain a specific number of water molecules (hydrate). The behavior of pharmaceutical hydrates has become the object of increasing attention over the past decade, primarily due to the potential impact of hydrates on the development process and dosage form performance. The present study was designed to characterize and evaluate the crystallinity of omeprazole sodium, dehydrated omeprazole sodium (DOMS) and omeprazole free base (OM) using a variety of techniques including thermal analysis (thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC)), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, scanning electron microscopy (SEM) and X-ray powder diffraction (XRPD). Furthermore, an NMR spectroscopy study was also carried out to clarify the conformation and crystal structure.

Comparative behavior studies of cinnamic acid using isothermal and nonisothermal kinetic methods

In this work, a thermal behavior study of cinnamic acid was made using isothermal and nonisothermal kinetics methods. Thermogravimetric curves were obtained to determine the kinetic parameters of its decomposition process. Cinnamic acid was melted at TPeak = 135.5°C and the decomposition started at 160°C. The obtained activation energy was 71.13 kJ/mol and 65.77 kJ/mol for isothermal and nonisothermal methods, respectively. The decomposition kinetics for both methods occurs at a constant rate, is of zero order, and is independent of the concentration of the reactants.

In Vitro Dissolution Profile of Dapagliflozin: Development, Method Validation, and Analysis of Commercial Tablets

Dapagliflozin was the first of its class (inhibitors of sodium-glucose cotransporter) to be approved in Europe, USA, and Brazil. As the drug was recently approved, there is the need for research on analytical methods, including dissolution studies for the quality evaluation and assurance of tablets. The dissolution methodology was developed with apparatus II (paddle) in 900 mL of medium (simulated gastric fluid, pH 1.2), temperature set at 37 ± 0.5°C, and stirring speed of 50 rpm. For the quantification, a spectrophotometric (λ = 224 nm) method was developed and validated. In validation studies, the method proved to be specific and linear in the range from 0.5 to 15 μg·mL−1 (r2 = 0.998). The precision showed results with RSD values lower than 2%. The recovery of 80.72, 98.47, and 119.41% proved the accuracy of the method. Through a systematic approach by applying Factorial 23, the robustness of the method was confirmed (p > 0.05). The studies of commercial tablets containing 5 or 10 mg demonstrated that they could be considered similar through f1, f2, and dissolution efficiency analyses. Also, the developed method can be used for the quality evaluation of dapagliflozin tablets and can be considered as a scientific basis for future official pharmacopoeial methods.

Development and validation of a dissolution test for primaquine/polyethylene oxide matrix tablets

A simple, precise, specific, repeatable and discriminating dissolution test for primaquine (PQ) matrix tablets was developed and validated according to ICH and FDA guidelines. Two UV assaying methods were validated for determination of PQ released in 0.1 M hydrochloric acid and water media. Both methods were linear (R2>0.999), precise (R.S.D.<1.87%) and accurate (97.65-99.97%). Dissolution efficiency (69-88%) and equivalence of formulations ( f2) was assessed in different media and apparatuses (basket/100 rpm and paddle/50 rpm) tested. Discriminating condition was 900 mL aqueous medium, basket at 100 rpm and sampling times at 1, 4 and 8 h. Repeatability (R.S.D.<2.71%) and intermediate precision (R.S.D.<2.06%) of dissolution method were satisfactory.