Spectrophotometric and Spectrofluorimetric Studies on Azilsartan Medoxomil and Chlorthalidone to Be Utilized in Their Determination in Pharmaceuticals

The recently approved angiotensin II receptor blocker, azilsartan medoxomil (AZL), was determined spectrophotometrically and spectrofluorimetrically in its combination with chlorthalidone (CLT) in their combined dosage form. The UV-spectrophotometric technique depends on simultaneous measurement of the first derivative spectra for AZL and CLT at 286 and 257 nm, respectively, in methanol. The spectrofluorimetric technique depends on measurement of the fourth derivative of the synchronous spectra intensities of AZL in presence of CLT at 298 nm in methanol. The effects of different solvents on spectrophotometric and spectrofluorimetric responses were studied. For, the spectrofluorimetric study, the effect of pH and micelle-assisted fluorescence enhancement were also studied. Linearity, accuracy, and precision were found to be satisfactory over the concentration ranges of 8–50 μg mL-1 and 2–20 μg mL-1 for AZL and CLT, respectively, in the spectrophotometric method as well as 0.01–0.08 μg mL-1 for AZL in the spectrofluorimetric method. The methods were successfully applied for the determination of the studied drugs in their co-formulated tablets. The developed methods are inexpensive and simple for the quality control and routine analysis of the cited drugs in bulk and in pharmaceuticals

Vitamin D Deficiency in Egyptian Systemic Lupus Erythematosus Patients: How Prevalent and Does it Impact Disease Activity?

Background The emerging role of vitamin D in immunology and autoimmune disorders has been a worldwide interest in the last decade. Systemic lupus erythematosus (SLE) patients are particularly at a delicate position predisposing them to suffer from vitamin D deficiency due to the multiple risk factors accompanying the disease. Whether vitamin D deficiency is also involved as a risk factor for developing SLE and affecting its course is a considerable concern. Objectives The objective of this study was to estimate the prevalence of vitamin D deficiency in SLE patients and its relation to disease. MATERIALS AND METHODS: In our observational cross-sectional study, serum levels of vitamin D [25(OH)D] in 60 SLE patients and 30 age- and sex-matched healthy controls were assessed and estimated for deficiency and insufficiency at 10 and 30 ng/mL, respectively. Disease activity was evaluated by SLE disease activity index (SLEDAI), irreversible organ damage by Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI), and severity by Severity of Disease Index. Fatigue was measured by visual analog scale. Results Significantly lower levels of 25(OH)D were found in SLE patients (17.6 ± 6.9 ng/mL) in comparison to controls (79.0 ± 28.7 ng/mL), with a statistically high significant difference ( t = -11.2, P < 0.001). High prevalence of vitamin D insufficiency and deficiency was detected as 73.3% and 23.3%, respectively. Vitamin D had a highly significant negative correlation with SLEDAI ( r = -0.495, P < 0.001), SLICC ( r = -0.431, P < 0.05), and fatigue ( r = -0.436, P < 0.05). Conclusion Vitamin D deficiency and insufficiency were found to be prevalent in SLE patients in our study and related to disease activity and fatigue. If needed, routine screening and consequent repletion of vitamin D are recommended in SLE patients. Restoring adequate vitamin D levels in SLE patients should be more explored as a potential yet simple measure to their usual management to improve their condition