THE fact that this text-book by Appleyard and Lyons has made its fourth appearance in ten years is sufficient evidence of its popularity. This new edition differs from its predecessors only by a slightly expanded chapter on qualitative organic analysis.Practical Pharmaceutical ChemistryBy F. N. Appleyard Dr. C. G. Lyons. Fourth edition. Pp. vii + 174. (London: Sir Isaac Pitman and Sons, Ltd., 1939.) 6s. 6d. net.

Practical In Pharmaceutical Chemistry

The objective of the current study was to develop a validated, specific stability-indicating reversed-phase liquid chromatographic (LC) method for the quantitative determination of escitalopram oxalate and clonazepam and their related substances in bulk drugs and pharmaceutical dosage forms in the presence of degradation products. Forced degradation studies were performed on the pure drugs of escitalopram oxalate and clonazepam, as per the stress conditions prescribed by the International Conference on Harmonization (ICH) using acid, base, oxidation, thermal stress and photolytic degradation to show the stability-indicating power of the method. Significant degradation was observed during acid and alkaline hydrolysis and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from forced degradation studies. Good resolution between the peaks corresponded to the active pharmaceutical ingredients, escitalopram oxalate and clonazepam, and degradation products from the analyte were achieved on an ODS Hypersil C18 column (250 3 4.6 mm) using a mobile phase consisting of a mixture of acetonitrile‐50 mM phosphate buffer 1 10 mM triethylamine (70:30, v/v). The detection was conducted at 268 nm. The limit of detection and the limit of quantitation for escitalopram oxalate and clonazepam were established. The stress test solutions were assayed against the qualified working standards of escitalopram oxalate and clonazepam, which indicated that the developed LC method was stability-indicating. Validation of the developed LC method was conducted as per ICH requirements. The developed LC method was found to be suitable to check the quality of bulk samples of escitalopram oxalate and clonazepam.

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Stability-Indicating RP-HPLC Method for the Simultaneous Determination of Escitalopram Oxalate and Clonazepam

A hetero-Fenton catalyst comprising of Fe3O4 nanoparticles loaded on zeolite (FeZ) has been synthesized using a facile co-precipitation method. The catalyst was characterized using various characterization methods and then, subsequently, was used to degrade ofloxacin (OFL, 20 mg·L−1), an antibiotic, via a heterogeneous Fenton process in the presence of an oxidizing agent. The effects of different parameters such as Fe3O4 loading on zeolite, catalyst loading, initial solution pH, initial OFL concentration, different oxidants, H2O2 dosage, reaction temperature, and inorganic salts were studied to determine the performance of the FeZ catalyst towards Fenton degradation of OFL under different conditions. Experimental results revealed that as much as 88% OFL and 51.2% total organic carbon (TOC) could be removed in 120 min using the FeZ catalyst. Moreover, the FeZ composite catalyst showed good stability for Fenton degradation of OFL even after five cycles, indicating that the FeZ catalyst could be a good candidate for wastewater remediation.

Fe3O4-Zeolite Hybrid Material as Hetero-Fenton Catalyst for Enhanced Degradation of Aqueous Ofloxacin Solution

A fast, specific, accurate and precise reverse phase high performance liquid chromatographic method was developed for the simultaneous determination of butenafine hydrochloride and betamethasone in cream formulation. The determination was carried out on licrocart licrosphere RP-select B (250Χ4.6 mm, 5 I…) column in isocratic mode, the mobile phase consisting of 50 mM ammonium acetate buffer and acetonitrile in the ratio of 60:40, adjusted to pH 4.5 ± 0.1 with glacial acetic acid. The flow rate was 2.0 ml/min and eluent was monitored at 254 nm. The retention times of butenafine hydrochloride and betamethasone were 4.70 min and 7.76 min, respectively, and the resolution factor was greater than 4.0. Linearity of butenafine hydrochloride and betamethasone were in the range of 100-300 μg/ml and 5-15 μg/ml, respectively. The proposed method is also found to be precise and robust for the simultaneous determination of butenafine hydrochloride and betamethasone in cream formulation.

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Simultaneous HPLC determination of butenafine hydrochloride and betamethasone in a cream formulation.

Escitalopram oxalate is a potent inhibitor of serotonin (5-HT) uptake that exhibit antidepressant activity. In spite of oxalate form it is sparingly soluble in water. The efficacy and bioavailability of Escitalopram oxalate is limited by its poor aqueous solubility and dissolution rate. The effect of hydrotropic (niacinamide) on the solubility of escitalopram oxalate was investigated. The saturation solubility indicate that enhancement in solubility was more than eight folds in 2M niacinamide compared to distilled water. Tablets of escitalopram oxalate with and without niacinamide were prepared and dissolution study was performed. Dissolution studies indicate that dissolution rate was remarkably increased with tablet containing niacinamide compared to tablets without niacinamide.

Solubility enhancement of escitalopram oxalate using hydrotrope

A reverse phase high performance liquid chromatography method was developed for simultaneous estimation of nitazoxanide and ofloxacin in tablet formulation. The separation and quantification was achieved by Hiq Sil C18 V Size 4.6 mm O *250 mm column in isocratic mode, with mobile phase consisting of acetonitrile-methanol-0.4 M citric acid, (60:30:10, v/v/v). Citric acid used to stabilize nitazoxanide and ofloxacin in mobile phase. The mobile phase was pumped at a rate of 0.6 ml/min and the detection was carried out at 304 nm. The retention time of ofloxacin and nitazoxanide was found to be 3.122 and 5.902 min, respectively. The method was validated for linearity, accuracy, and precision. Linearity for ofloxacin and nitazoxanide were in the range 2-36 mg/ml and 5-90 mg/ml, respectively. The developed method was found to be accurate, precise and selective for simultaneous estimation of ofloxacin and nitazoxanide in tablets.

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V.R. Choudhary

Papers

RP-HPLC method for simultaneous estimation of nitazoxanide and ofloxacin in tablets

Zero Order Spectrophotometric Method for Estimation of Escitalopram Oxalate in Tablet Formulations