Simultaneous determination of vitamin B6 and magnesium using capillary electrophoresis coupled with contactless conductivity detection: Method development, validation, and application to pharmaceutical and nutraceutical samples.

Vitamins and minerals are usually incorporated in pharmaceutical and nutraceutical products, but a simple, rapid, and inexpensive analytical method for their simultaneous determination is still lacking. In this study, we developed a quantification method for pyridoxine (vitamin B6) and magnesium (Mg) by using purpose-made capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D) instrument. Main analytical conditions include: fused silica capillary (total length 55 cm, effective length 40 cm, inner diameter 50 µm); background electrolyte consisted of 10 mM L-arginine/acetic acid (pH 5) with 20% acetonitrile; separation voltage + 20 kV; hydrodynamic injection (siphoning at 20 cm in 25 s). Detection limits of vitamin B6 and Mg were 1 and 0.1 mg/L, respectively. Good linearity (R2 > 0.999) was observed for vitamin B6 and Mg calibration curves over concentration ranges of 3-100 and 0.3-200 mg/L, respectively. The method was applied to analyze vitamin B6 and Mg in several pharmaceutical and nutraceutical samples. The analytical results obtained by our method were in good agreement with reference methods (i.e., HPLC for vitamin B6 and ICP-OES for Mg). High-efficient and low-cost CE-C4D method can accordingly serve as a promising tool for concurrent analysis of inorganic and organic species in pharmaceutical and nutraceutical analysis.

Distribution of Malassezia Species from Scales of Patient with Pityriasis Versicolor by Culture in Vietnam.

BACKGROUND: The detection of pathogenic fungus is an important step and key to assessing the sensitivity of the antifungal drugs, and therefore choosing an effective treatment method. AIM: To identify Malassezia species from scales of a patient with pityriasis versicolor. METHODS: Three hundred patients with pityriasis versicolor who were positive with direct examination, were isolated by culture. RESULTS: Identification of Malassezia species by culture: the growth rate was 90.3%; the detection rate was 97.0%, including 11 species: M. globosa (42.4%), M. dermatitis (17.3%), M. furfur (14.4%). M. globosa was the most prevalent species in the 20-29 group 36.5%, in hyphae and yeast cells (42.2%). CONCLUSION: M. globosa is the main cause of pityriasis versicolor in Vietnam.

Clinical Aspects and Treatment of Pityriasis Lichenoides Et Varioliformis Acuta: A Retrospective Vietnamese Study.

BACKGROUND: Pityriasis lichenoides et varioliformis acuta (PLEVA) is an uncommon condition which presents acutely with papulo-vesicles that may develop necrotic, ulcerative, or hemorrhagic changes. AIM: We studied clinical, and treatment characteristics of PLEVA hospitalised patients at our hospital from September 2009 to December 2014. METHODS: The records of 15 PLEVA patients were retrospectively reviewed. RESULTS: The median age of onset was 21.8 ± 18.81 (from 1 to 68), male to female ratio was 2/1. The common area of onset was trunk (60.0%) and extremities (33.3%). Clinical features were purpuric papules (100%), hemorrhagic crusted papules (46.7%), pustular purpuric papules (40%), and necrotic ulcerating lesions (13.3%). CONCLUSION: All patients were received systemic antibiotics (macrolides: 53.3%, others: 46.7%), 2 patients were added immunosuppressive drugs. A 1-year-old patient died, others had a good response.

Efficacy of Azole Antifungal in Treatment of Pityriasis Versicolor.

AIM: Compare itraconazole alone, fluconazole combined with ketoconazole and ketoconazole in the treatment of patients with pityriasis versicolor. MATERIAL AND METHODS: A group of 240 pityriasis versicolor patients (confirmed with KOH and culture) were classified into 3 groups: Fluconazole 300 mg a week and 2% ketoconazole foam twice a week for 2 weeks (Category I), Itraconazole 200 mg daily for one week (category II); Ketoconazole 2% foam daily for 2 weeks (Category 3). Clinical (colour of macule, scale, pruritus) and mycological assessment were done after 4 weeks of therapy. RESULTS: After 4 weeks of treatment, clinical cure was observed in 62.4% (Category I), 36.3% (Category II) and 37.5% (Category III). CONCLUSION: It was reported in our study that the most effective regimen for PV patients is fluconazole 300 mg per week combined with ketoconazole 2% twice a week for 2 weeks.