Validated stability indicating liquid chromatographic determination of ebastine in pharmaceuticals after pre column derivatization: Application to tablets and content uniformity testing

An accurate, simple, sensitive and selective reversed phase liquid chromatographic method has been developed for the determination of ebastine in its pharmaceutical preparations. The proposed method depends on the complexation ability of the studied drug with Zn2+ ions. Reversed phase chromatography was conducted using an ODS C18 (150 × 4.6 mm id) stainless steel column at ambient temperature with UV-detection at 260 nm. A mobile phase containing 0.025%w/v Zn2+ in a mixture of (acetonitril/methanol; 1/4) and Britton Robinson buffer (65:35, v/v) adjusted to pH 4.2, has been used for the determination of ebastine at a flow rate of 1 ml/min. The calibration curve was rectilinear over the concentration range of 0.3 - 6.0 μg/ml with a detection limit (LOD) of 0.13 μg/ml, and quantification limit (LOQ) of 0.26 μg/ml. The proposed method was successfully applied for the analysis of ebastine in its dosage forms, the obtained results were favorably compared with those obtained by a comparison method. Furthermore, content uniformity testing of the studied pharmaceutical formulations was also conducted. The composition of the complex as well as its stability constant was also investigated. Moreover, the proposed method was found to be a stability indicating one and was utilized to investigate the kinetics of alkaline and ultraviolet induced degradation of the drug. The first-order rate constant and half life of the degradation products were calculated

Validated stability-indicating spectrofluorimetric methods for the determination of ebastine in pharmaceutical preparations

Two sensitive, selective, economic, and validated spectrofluorimetric methods were developed for the determination of ebastine (EBS) in pharmaceutical preparations depending on reaction with its tertiary amino group. Method I involves condensation of the drug with mixed anhydrides (citric and acetic anhydrides) producing a product with intense fluorescence, which was measured at 496 nm after excitation at 388 nm

The role of diffusion-weighted MRI: In assessment of response to radiotherapy for prostate cancer

Objective: The objective of our study was to investigate the changes of apparent diffusion coefficient (ADC) values in prostate cancers before and after radiotherapy at 1.5 T using a phased-array coil. Materials and methods: Twenty-five patients with biopsy-proven prostate cancer who received radiotherapy underwent diffusion-weighted imaging (DWI) at 1.5 T and were included in the study. Biopsies in all patients were performed before the initial MRI examination (range, 15–30 days before MRI; mean, 21.1 days). All 25 patients underwent DWI (b values = 0 and 1000 s/mm2) before and 1–3 months after the completion of radiotherapy. The changes in ADC values were measured for cancers and benign tissues before and after therapy. Additionally, the changes in serum prostate-specific antigen (PSA) levels were evaluated before and after therapy. Results: The mean ADC value after therapy (1.418 × 10−3 mm2/s) was increased compared with the mean ADC value before therapy (0.756 × 10−3 mm2/s) (p  0.5). The median PSA level after therapy (1.39 ng/mL) was decreased compared with the median PSA level before therapy (27.20 ng/mL). Conclusion: With the use of a 1.5-T MR scanner, our preliminary results suggest that ADC values may be useful as a non-invasive imaging biomarker for monitoring therapeutic response of prostate cancer to radiotherapy

Role of multiphasic multi-detector computed tomography (MDCT) in the diagnosis and staging of solid neoplastic renal masses

Objectives: The aim of this study was to assess the role of multi-detector computed tomography (MDCT) in diagnosis and preoperative staging of solid renal masses. Patients and methods: During two years duration we prospectively evaluated 56 patients with solid renal lesions previously detected by US. All patients underwent multiphasic CT scanning for the kidneys and urinary tract following a preset scanning protocol that included unenhanced, corticomedullary phase (CMP), nephrograhic phase (NP) and excretory phase (EP) scanning. The images obtained in the excretory delayed phase were reconstructed in different planes to obtain 2D and 3D reformatted images providing volume rendering VR and maximum intensity projection (MIP) CTU images. Curved reformatting was sometimes used for the ureter. The numbers of lesions detected in all three phases were determined. Results of CT scan were compared with histopathology or constellation of clinical and imaging patient data. Results: A total of 61 masses were detected in 56 cases, 51 cases had unilateral masses (91%), 5 cases had bilateral masses (9%). The different pathologies encountered in the study were RCC 39 masses (64%), Wilm’s tumor 3 masses (4.9%), transitional cell carcinoma 3 masses (4.9%), angiomyolipoma 7 masses (11.5%), lymphoma 6 masses (9.8%), metastasis one mass (1.6%), angiomyolipoma associated with RCC two masses (3.3%). Lymph nodal metastasis, renal vein, IVC thrombosis and distant metastatic spread in different pathologies were assessed. The attenuation HU values calculated in the early CMP for all cases of RCC had a mean value of 80.5 HU (STD 45.7) while the mean values in NP and EP were 70.6 HU (STD 25.4) and 51.3 HU (STD 19.2) respectively. A pattern of enhancement was detected in all cases of RCC in the form of rapid wash out of contrast and decrease of attenuation (HU) by time throughout different phases. Significant difference between HU in CMP and EP in cases of RCC (P value = 0.0002) and difference between HU in NP and EP in cases of RCC (P value < 0.00001) were found. Conclusion: Multiphase multislice computed tomography combined with CT angiography and CT urography have a major role in solid renal neoplastic masses’ diagnosis, characterization and differentiating benign and malignant tumors

Diagnostic accuracy of the different pulse sequences of multi-parametric prostate MRI in the diagnosis of prostate cancer in the peripheral and transitional zones

Abstract Background One of the most prevalent malignancies among males is prostate carcinoma (PCa). For the diagnosis of PCa, multiparametric magnetic resonance imaging (mpMRI) constitutes by far the most accurate imaging technique. The PI-RADS v2.1 indications for dynamic contrast enhanced (DCE) sequence include identifying PI-RADS score 3 lesions, as clinically significant prostate carcinoma, aiding evaluation of examinations having poor quality of T2 as well as diffusion weighted imaging (DWI), and helping readers having relatively reduced expertise. Most articles don't provide outcomes pertaining to these indications, which weakens their conclusions. All MRI scans, even those with low quality T2 or DWI, were included in our study. Additionally, special emphasis on assessing peripheral zone lesions was made. Our objective was to assess the diagnostic accuracy of the various mpMRI pulse sequences, including the T2 sequence, diffusion and apparent diffusion coefficient (ADC) sequences, both T2 and diffusion sequences (biparametric (bp) MRI), DCE sequence, and the entire examination (mpMRI), in the diagnosis of PCa in the peripheral as well as the transitional zone using PI-RADS version 2.1 scoring system, once when malignant lesions are considered as those having PI-RADS scores 4 and 5 and once when PI-RADS categories 3, 4 and 5 were regarded as malignant. Results In the assessment of peripheral zone lesions, when PI-RADS categories 3, 4, and 5 were considered malignant, both bpMRI and mpMRI showed similar sensitivity (94.29%) and diagnostic accuracy (77.78%) while when considering scores 4 and 5 malignant, mpMRI demonstrated increased diagnostic accuracy and sensitivity but lower specificity (sensitivity was 82.86%/60%, specificity was 80%/100%, and diagnostic accuracy was 82.22%/68.89% for mpMRI/bpMRI test comparaison). Both bpMRI and mpMRI had similar sensitivity (95.83%) and diagnostic accuracy (71.05%) when PI-RADS categories 3, 4, and 5 were regarded as malignant; however, mpMRI demonstrated better diagnostic accuracy and sensitivity considering scores 4 and 5 malignant (sensitivity was 77.08% for mpMRI compared to 60.42% for bpMRI and diagnostic accuracy was 82.89% for mpMRI compared to 75% for bpMRI). Conclusions Both bpMRI and mpMRI demonstrated similar diagnostic accuracy when PI-RADS categories 3, 4, and 5 were taken into account as malignant while mpMRI had higher diagnostic accuracy considering categories 4 and 5 malignant