H. N. Alkaysi

Chemical and microbiological investigations of metal ion interaction with norfloxacin

Abstract This report describes a spectrophotometric study on the interaction between norfloxacin (NFX) and metal ions (Al 3+ , Mg 2+ and Ca 2+ ). Two buffers of pH 3.6 and 8.8 were used. A shift in absorption maximum was observed and the stoichiometry of the complex was determined using the Job and molar methods. The ratios were NFX:AL 3+ , 2:1 and 3:1 for the NFX:Mg 2+ complex. The formation of a complex with Al 3+ enhanced the water solubility of the drug. Microbiological studies indicated decreased activity of norfloxacin in the presence of metal ions.

HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC ANALYSIS OF CAFFEINE CONCENTRATIONS IN PLASMA AND SALIVA

A rapid high performance liquid chromatographic (HPLC) method for the analysis of caffeine in plasma and saliva is described. Samples of saliva and plasma were purified using zinc sulphate solution as protein precipitant. The supernatant was injected directly onto the column. The mobile phase consisted of ammonium acetate buffer:acetonitrile:methanol (82:15:3, v/v).

HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC ANALYSIS OF RANITIDINE IN PLASMA AND URINE

A high‐performance liquid chromatographic method for the analysis of ranitidine in plasma and urine is described. Plasma samples were extracted with dichloromethane while urine samples were injected directly after dilution. The mobile phase consisted of: 0·05 m ammonium acetate buffer containing 0·01 m octane sulphonate, 5·3%; methanol, 31·6%; and acetonitrile, 63·1%. Detection was carried out at 330 nm. Metoclopramide was used as the internal standard. Peak height ratios were measured. Absolute recovery from plasma was 83–85%. Within and between day coefficients of variation ranged from 0·79 to 2·42% and 1·09–2·95% respectively. Plasma and urine samples from a healthy volunteer were analysed.

Quantitation of Orphenaorine Citrate and Acetaminophen In Tablet Formulation Using Thin Layer Chromatography Densitometry

Abstract A thin layer chromatographic method for the quantitative determination of orphenadrine citrate and acetaminophen in tablet formulations was developed. the method involves direct application of methanolic tablet suspensions on silica gel plates. the eluent used for the development consisted of toluene, ethyl acetate, propylene glycol and acetic acid. Linearity and reproducibility were evaluated. Recovery of active ingredients from dosage forms was calculated. the method is simple and does not require sample manipulation prior to analysis.

High Pressure Liquid Chromatographic Analysis of Orphenadrine Citrate and Acetaminophen in Pharmaceutical Dosage Forms

Abstract An ion pair reversed phase high pressure liquid chromatographic method for the analysis of orphenadrine citrate (I) and acetaminophen (II) was developed. The mobile phase consisted of 20mM sodium-1-octane sulfonate in 50mM phosphate buffer (pH=3.0), mixed with 22.5% organic solvents (50:50, acetonitrile: methanol). The method is simple, reliable and could be adapted for quality control purposes.

Terfenadine determination using different analytical methods

Abstract Different methods for terfenadine determination were investigated. Non-aqueous titration and TLC techinques were used to assay the starting material. TLC method was found to be more selective in differentiating between batches of different purity. The drug solution in a mixture of methanol, acetic acid and water exhibited two maxima at 238 and 260 nm. The pharmaceutical dosage forms were assayed by the formation of an ion pair complex with methyl orange, which was extracted in dichloromethane and showed a maximum at 425 nm. The colour obtained was stable and the complex obeyed the Beer Lambert law between 0.004–0.016 mg/ml. The optimum pH of the aqueous layer was from 3.5–6.0. This method was applied for tablets, capsules, suspension and content uniformity assays and was found to be simple and reproducible.

BIOEQUIVALENCY OF RANITIDINE TABLETS

The bioavailability of two brands of ranitidine tablets was studied in 10 healthy volunteers. Formulation factors were compared by performing disintegration, dissolution and content uniformity tests. Plasma concentrations of ranitidine were measured using a sensitive and precise high pressure liquid chromatographic (HPLC) procedure. Pharmacokinetic parameters were determined for both formulations and included: Cmax, AUCt, AUCx, tmax, t1/2 and the terminal rate of elimination (k). Statistical analysis revealed that differences between the brands were not significant. The two formulations can be considered to be bioequivalent.

Preparation, characterisation and transformation of terfenadine polymorphic forms

Polymorphic modifications of terfenadine as well as solvates from various solvents have been prepared and characterised by X-ray powder diffraction (XRPD), infrared (IR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis. Crystallization of terfenadine from n-alkanols, except methanol and ethanol, resulted in the stable polymorph 1 (m.p. 151°C) while the iso-alkanols yielded the corresponding solvates. Water content, temperature of incubation and duration were found to have significant effect on transformation.

High Pressure Liquid Chromatographic Analysis and Dissolution of Famotidine in Tablet Formulation

Abstract A reversed phase high pressure liquid chromatographic method was developed for the quantitation of famotidine in tablet formulation using a mobile phase consisting of 0.1M phosphate buffer (84%), acetonitrile (11%) and methanol (5%) at a pH of 6.5. The detection wavelength was set at 285 nm. The method is precise and adaptable for quality control purposes. The use of the analytical method hi studying tablet dissolution is described.

High Pressure Liquid Chromatographic Analysis and Dissolution of Sulphadiazine and Tetroxoprim in Tablet Dosage Form

Abstract A reversed phase high pressure liquid chromatographic method for the analysis of tetroxoprim (I) and sulphadiazine (II) was developed. The mobile phase consisted of 0.1M triethylammonium acetate (84%), acetonitrile (13%) and methanol (3%), with unadjusted pH. The detection wavelength was set at 280 nm. The method is simple, reliable and could be adapted for quality control purposes. The use of the analytical method in studying tablet dissolution is described.