Application of HPTLC, spectrofluorimetry and differential pulse voltammetry for determination of the antifungal drug posaconazole in suspension dosage form.

This work presents the development, validation and application of three simple and direct analytical methods for determination of posaconazole (PSZ) in its pure form and in suspension dosage form. Method I is based on high performance thin layer chromatography (HPTLC) where effective separation of PSZ and the internal standard (itraconazole) was achieved using Merck HPTLC plates (20×10cm aluminium plates with 250µm layer thickness precoated with silicagel 60 F254) and a mobile phase composed of acetone and chloroform (1:2, by volume), followed by densitometric measurement of the drugs' spots at 262nm. Method II involves measurement of the native fluorescence of PSZ in 0.1M H2SO4 at excitation and emission wavelengths of 260 and 365nm, respectively. Method III depends on the voltammetric analysis of PSZ. A well-defined cathodic wave was obtained for PSZ in Britton-Robinson buffer pH 6.5 using the differential-pulse mode at the hanging mercury drop electrode (HMDE). The developed methods were validated according to the International Conference on Harmonization (ICH) guidelines regarding linearity, ranges, accuracy, precision, robustness and limits of detection and quantification. The proposed methods showed good linearity over the concentration ranges 5-50, 0.05-0.3, 0.005-0.05µg/mL PSZ for methods I, II, and III respectively. Intra and inter-day precision were verified by the RSD% values which were less than 2%. The proposed methods were successfully applied for the quantification of PSZ in suspension dosage form with no observable interferences. Assay methods were favorably compared with those obtained by previously reported HPLC method.

Alteration of redox status by commonly used antimalarial drugs in the north-western region of Nigeria.

This study was designed to investigate the alteration of redox status by commonly used antimalarials in Nigeria. Drugs used were artemisinin, artesunate, chloroquine, coartem and quinine at the final concentrations of 0.5-8.0 mg/mL. Blood samples were collected from malarial patients and apparently healthy humans for comparison. Reduced glutathione, catalase, superoxide dismutase (SOD) activities, protein content and lipid peroxidation were determined. All drugs significantly ( p < 0.05) increases the protein level relative to control in normal blood, whereas in the infected, a significant ( p < 0.05) reduction was observed. In normal blood, the antimalarials dose dependently decreased ( p < 0.05) SOD and catalase activities with significant ( p < 0.05) increase in the infected. The level of glutathione in normal blood significantly ( p < 0.05) increases as compared with control, whereas in the infected, similar observation was made except that the levels were less, relative to control sample. Malondialdehyde level significantly ( p < 0.05) increases with increase in drugs concentration even though less than the level in the control with few exceptions. These effects were dose dependent and more pronounced in non-malarial conditions. Commonly used antimalarials might alter the redox status in both healthy and non-healthy subjects thereby inducing oxidative stress.

Clinical course and pathologic features of conjunctival non-Hodgkin's lymphoma. A report of six cases.

Six patients with conjunctival non-Hodgkin's lymphoma (NHL) were evaluated. In all six cases the conjunctiva was the primary site of clinical presentation; four cases involved low-grade malignancy and two, intermediate-grade malignancy, according to the International Working Formulation. The disease developed within a short period of time to stage IV. The poor response to therapy revealed a worse prognosis than would be expected according to the histopathologic classification. Four of the six patients died of NHL, three of them within 15 months. Comparison of these 6 cases with a group of 15 patients with orbital NHL revealed a much better prognosis in the latter patients. In spite of the fact that 4 of the 15 orbital cases showed NHL of high-grade malignancy, only 2 of them died of the lymphoma. Therefore, conjunctival NHL requires a fast and adequate diagnostic and therapeutic approach.

The permeability of the corneal epithelium of Graves' ophthalmopathy as determined by fluorophotometry.

The function of the corneal epithelium was evaluated in 30 patients with Graves' ophthalmopathy in whom no signs of corneal disease were observed. This function was evaluated by determining the permeability values of the corneal epithelium for fluorescein using fluorophotometry. The permeability values of the patients were compared with those of 46 healthy individuals. A significant increase in the permeability values was seen in 11 (37%) patients and in two (4%) controls (p less than 0.05). The difference in the mean permeability values between patients en controls was statistically significant (0.053 nm/sec. +/- 0.043 SD and 0.038 nm/sec. +/- 0.017 SD, respectively, p less than 0.05). No relation was found between the permeability values of the corneal epithelium and the NOSPECS classification or the duration of the disease. There was a tendency for increased permeability values in patients having an exophthalmos larger than 20 mm. (correl. coeff. = + 0.3, p less than 0.05).

Secretory IgA and lysozyme in tears of patients with Graves' ophthalmopathy.

Using an enzyme linked immuno-assay (ELISA) and spectrophotometry, we determined levels of secretory IgA and lysozyme in tears of 69 patients with Graves' ophthalmopathy and 28 controls. The quantitative determination of secretory IgA and lysozyme in tears provided an impression of the functioning of the lacrimal gland in the two groups. An IgA/lysozyme ratio was calculated in both patients and controls as a parameter for the activity of the secretory IgA-producing plasma cells in the lacrimal gland. An increase in the IgA/lysozyme ratio was observed in 23 patients (33%) and one control (3%). Half of the patients who had suffered from the disease for more than 5 years showed a raised IgA/lysozyme ratio. No correlation was found between the IgA/lysozyme ratio and the NOSPECS classification. Our findings suggest that the lacrimal gland is involved in the orbital condition produced by Graves' ophthalmopathy. In most cases the involvement occurs in patients with a long history of the disease.

Analysis of tear proteins in Graves' ophthalmopathy by high performance liquid chromatography.

Using high performance liquid chromatography, we analyzed tears from 50 patients with Graves' ophthalmopathy and 20 controls. With this technique, tear constituents are separated according to size; a normal tear protein profile consists of five peaks. An increase in one or more peaks was observed in 14 patients (28%) and in none of the controls. No decreased values were observed. No relation was observed between abnormalities of tear composition and the clinical NO SPECS classification. There was a tendency for increased tear protein peaks in those patients with long-standing disease. Most patients with an increase in one or more tear protein levels had normal thyroid function after treatment for hyperthyroidism. Our findings suggested that the inflammatory process in the orbit occurring in Graves' ophthalmopathy also had an effect on the lacrimal gland, which was reflected in the composition of the tears.