Formulation development and optimization of taste masked generic fast dissolving zinc sulphate tablets

Zinc sulphate tablets are indicated for the management of diarrhoea in children regardless of the cause. In Tanzania, there is only one pharmaceutical industry manufacturing zinc sulphate tablets and only 44% of children in need of zincsulphate tablets get access to them. Fast-disintegrating tablets of zinc sulphate were prepared by direct-compression method after incorporating the superdisintegrant polyvinyl pyrollidine cross-linked. Different types of experiments and evaluation parameters for tablets were assessed. Design expert software version 7 was used to optimize the formulation. Tablets containing polyvinyl pyrollidine cross-linked showed excellent disintegration time, friability and hardness compared to formulations containing other superdisintegrants. Tablets with 30mg/60mg sodium saccharin/strawberry had a palatable taste. Assay was within 95% to 105%, disintegration time was less than 60 seconds, and hardness was between 3.0 kg/cm2 to 4.0 kg/cm2, which comply with official US Pharmacopeia requirements. Therefore, a taste masked generic formulation of 20 mg zinc sulphate fast dissolving tablets with accurate dose and palatable taste was successfully developed and optimized.Keywords: Zinc sulphate monohydrate, Fast disintegrating tablets, Disintegration tim

Development and validation of an HPTLC densitometric method for assay of griseofulvin in tablets

A new HPTLC densitometric method for the assay of griseofulvin tablets was developed and validated according to ICH guidelines and USP specifications. The method was developed using a mobile phase prepared with an environmentally friendly solvent system, diethyl ether: toluene (4:1) on pre-coated TLC silica gel 60F254 glass plates with a saturation time of 25 min. Development time of 10 min was required for a migration distance of 70 mm. The best detection wavelength was 299 nm. The Rf value was 0.22 and there were no interferences from the excipients or solvents. With regard to repeatability and intermediate precision, the RSD values were 1.43 and 1.58, respectively. Linearity testing gave the polynomial R2 values, calculated on three consecutive days, of 0.9910, 0.9801 and 0.9840, respectively. The accuracy values tested at 80 %, 100 % and 120 % concentrations were between 98.11-102.66 %. The developed HPTLC densitometric method for the assay of griseofulvin tablets is simple, selective, accurate, reproducible, high throughput, cost-effective and environmentally friendly.Keywords: High Performance Thin Layer Chromatography (HPTLC), griseofulvin, densitometry, validatio

Stability indicating liquid chromatographic method for determination of lamivudine and tenofovir disoproxil fumarate in fixed dose combination formulations

This study describes the development and validation of a stability indicating high performance liquid chromatographic method for the analysis of lamivudine and tenofovir disoproxil fumarate and their degradants. The method uses a Reprosil®-pur basic C18 column (250 mm × 4.6 mm, 5 μm) maintained at 30°C, methanol and a mixture of buffers (2.3 g/L ammonium dihydrogen phosphate and 1.32 g/L of diammonium hydrogen phosphate, pH 3.9) for gradient elution at a flow rate of 1.0 mL/min, and UV detection at 270 nm. Good separation of lamivudine and tenofovir disoproxil fumarate and their potential impurities was achieved. The stability indicating ability of the developed method was validated by subjecting both active ingredients to hydrolytic and oxidative stress conditions and separating the degradation products from their respective intact drugs. The calibration curve was linear over the 80-120 μg/mL concentration range for both active ingredients with r2> 0.99. A recovery rate of 99.8 % for lamivudine and 99.3 % for tenofovir disoproxil fumarate confirmed the accuracy of the method for the simultaneous determination of both drugs in the fixed-dose combination.Keywords: Stability indicating liquid chromatography, lamivudine, tenofovir, validatio