An-Najah Staff

Arum palaestinum Boiss, a wild edible plant in Palestine, is one of about 26
species of the arum genus which are flowering plants belonging to Araceae. The
plant is widely used in Traditional Arabic Palestinian Herbal Medicine
(TAPHM) in the treatment of several human diseases mainly cancer. This
investigation reports the separation and identification of phthalate compounds
such as dipropyl phthalate, diisobutyl phthalate and di-n-octyl phthalate for the
first time from the extract of Arum palaestinum, using HPLC and GCMS
techniques. In addition to these finding the amounts of phenolics, flavonoids and
phthalate contents were evaluated in the whole plant. Total phenolics were found
to be 3.9μg/mg pyrocatechol equivalent, and total flavonoids were found to be
270μg/mg as quercetin equivalent. One of the interesting results of this study also
was the evaluation of phthalates in different parts of the plant. Average values of
phthalates in the fresh plant parts were (36.3, 26.1, 5.6, 7.0μg/g) in leaves,
inflorescence, stem and inflorescence base respectively. In addition, the average
values of phthalates in different areas of Nablus region for whole plant were 48.3,
53.0, 50.9 μg/g. The findings of this study is discussed with relation to medicinal
and food uses of the plant in Palestinian communities.

The aim of this study is to assess the quality of Valzan^® tablet (160 mg, valsartan immediate release test formulation) by comparing its pharmacokinetic parameters with Diovan^® tablet (160 mg, valsartan reference formulation). Valzan^® tablets were prepared according to a dry granulation method (roll compaction). To assess the bioequivalence of Valzan^® tablets a randomized, two-way, crossover, bioequivalence study was performed in 24 healthy male volunteers. The selected volunteers were divided into two groups of 12 subjects. One group was treated with the reference formulation (Diovan^®) and the other one with the generic Valzan^®, with a cross-over after the drug washout period of 14 days. Blood samples were collected at fixed time intervals and valsartan concentrations were determined by a validated HPLC assay method. The pharmacokinetic parameters AUC_0–48, AUC_0–∞, C_max, T_max, K_e and T_1/2 were determined for both the tablets and were compared statistically to evaluate the bioequivalence between the two brands of valsartan, using the statistical model recommended by the FDA. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals (CI) fell within the acceptable range for bioequivalence. Based on this statistical evaluation it was concluded that the test tablets (Valzan^®) is well formulated, since it exhibits pharmacokinetic profile comparable to the reference brand Diovan^®.

This study was aimed to develop valsartan/ hydrochlorothiazide tablet formulation and to develop a stability indicating HPLC method for their analysis in raw materials and in its final dosage form according to the ICH guidelines. Film coating tablets containing valsartan and hydrochlorothiazide were developed. A gradient HPLC method was performed; the flow rate was 1.5 ml/min, injected volume 20μL, the mobile phases consist of two solvent: Solvent A (0.20 M ammonium acetate, adjusted to pH 5.6 with glacial acetic acid) and Solvent B (acetonitrile) and UV detection was carried out at 265nm. Valsartan and hydrochlorothiazide and their combined dosage form were exposed to thermal, oxidative, acid-base hydrolytic stress conditions, the stressed samples were analyzed. The method was validated with respect to linearity, precision, accuracy, system suitability, and robustness. The used method is specific for the estimation of valsartan and hydrochlorothiazide in presence of their degradation products and impurities. The method was linear over the range of 2.5–32μg/mL and 17.5-224μg/mL for valsartan and hydrochlorothiazide respectively. The mean recoveries were 100±2% for valsartan and hydrochlorothiazide respectively. The percentage of relative standard deviation (%RSD) was found to be less than critical value. Our developed analytical method is a stability indicating, economical and easy method which is useful in the quality control of valsartan and hydrochlorothiazide in tablet dosage forms.

Diminazene aceturate and Antipyrine combination therapy is widely used in veterinary medicine. A simple reverse HPLC method for the analysis of samples of a ready injectable formulation containing a mixture of active ingredients and inactive excipients has been developed. The HPLC analysis was carried out using a reversed phase (RP)-C18 (250 mm×4.0 mm, 5 μm) column. The isocratic mobile phase consisted of a mixture of acetonitrile, methanol, phosphate buffer and hexane sulfonate; the flow rate was 0.6 mL/min and ultraviolet detection was at 291 nm. This method was validated in accordance with FDA and ICH guidelines and showed good linearity, accuracy, precision, selectivity and the system suitability results were within the acceptance criteria. A stability-indicating study was also carried out and indicated that this method could be used for purity and degradation evaluation of these formulations.

Diminazene aceturate and Antipyrine combination therapy is widely used in veterinary medicine. A simple reverse HPLC method for the analysis of samples of a ready injectable formulation containing a mixture of active ingredients and inactive excipients has been developed. The HPLC analysis was carried out using a reversed phase (RP)-C18 (250 mm×4.0 mm, 5 μm) column. The isocratic mobile phase consisted of a mixture of acetonitrile, methanol, phosphate buffer and hexane sulfonate; the flow rate was 0.6 mL/min and ultraviolet detection was at 291 nm. This method was validated in accordance with FDA and ICH guidelines and showed good linearity, accuracy, precision, selectivity and the system suitability results were within the acceptance criteria. A stability-indicating study was also carried out and indicated that this method could be used for purity and degradation evaluation of these formulations.

Differential-pulse adsorptive cathodic stripping voltammetric (DP-AdCSV) and high performance liquid chromatography (HPLC) techniques were developed for quantitative determination of Reactive Blue 19, Reactive Red 198 and Reactive Orange 107 textile dyes. The calibration curves using the DP-AdCSV method were found to be linear over the ranges 0.05-1.0 ppm, 0.10-1.10 ppm and 0.05-1.0 ppm, respectively. The HPLC method is based on using a mobile phase consisting of acetonitrile:water (60:40, v/v) containing 0.45 M N-Cetyl-N,N,N-trimethylammonium bromide (CTAB) and buffered to pH 7.92. Reverse phase RP C18 column was used with a flow rate of 0.6 ml/minute. The retention times for Reactive Blue 19, Reactive Red 198 and Reactive Orange 107 were found to be 5.4 min, 7.8 min and 2.3 min, respectively. The calibration curves were found to be linear over the ranges 0.1-5.0 ppm, 0.1-1.2 ppm and 0.05-1.5 ppm, respectively.

This study was aimed to develop valsartan/ hydrochlorothiazide tablet formulation and to develop a stability indicating HPLC method for their analysis in raw materials and in its final dosage form according to the ICH guidelines. Film coating tablets containing valsartan and hydrochlorothiazide were developed. A gradient HPLC method was performed; the flow rate was 1.5 ml/min, injected volume 20μL, the mobile phases consist of two solvent: Solvent A (0.20 M ammonium acetate, adjusted to pH 5.6 with glacial acetic acid) and Solvent B (acetonitrile) and UV detection was carried out at 265nm. Valsartan and hydrochlorothiazide and their combined dosage form were exposed to thermal, oxidative, acid-base hydrolytic stress conditions, the stressed samples were analyzed. The method was validated with respect to linearity, precision, accuracy, system suitability, and robustness. The used method is specific for the estimation of valsartan and hydrochlorothiazide in presence of their degradation products and impurities. The method was linear over the range of 2.5–32μg/mL and 17.5-224μg/mL for valsartan and hydrochlorothiazide respectively. The mean recoveries were 100±2% for valsartan and hydrochlorothiazide respectively. The percentage of relative standard deviation (%RSD) was found to be less than critical value. Our developed analytical method is a stability indicating, economical and easy method which is useful in the quality control of valsartan and hydrochlorothiazide in tablet dosage forms.

This study was undertaken to evaluate the significance of pharmacokinetic interaction between ciprofloxacin and licorice (Glycerhyza glabra). The study was designed as a comparative, randomized, two-period, two-treatment, two-sequence, single dose, crossover study in order to investigate the effect of licorice extract on ciprofloxacin in 12 rabbits (1.8-3.2kg). Rabbits were administered single oral doses of 40 mg/kg ciprofloxacin either with licorice extract or water. A simple and sensitive high performance liquid chromatography method for the detection and quantification of ciprofloxacin in rabbit plasma was developed specifically for this study. The resulting concentrations versus time curves were analyzed using non–compartmental pharmacokinetic analysis. Study results showed that licorice extract slightly reduced the rate and extent of ciprofloxacin absorption to around 80% [maximum plasma concentration (Cmax); from 1714 ng/ml to 1241 ng/ml, with a p-value of 0.25 and a 90% confidence interval (90% CI) 43.930–119.3 and the area under the plasma concentration time curve from zero to infinity (AUC∞); from 6964 ng.hr/ml to 5777 ng.hr/ml, with a p-value of 0.33 and a 90% CI 58.8–117.4 ng.hr/ml]. This interaction is speculated to be due to the interaction between the metals in the licorice extract and ciprofloxacin. In conclusion, the non-statistically significant pharmacokinetic interaction between ciprofloxacin and licorice that was observed in this study is not expected to have significant clinical consequences.