Simultaneous determination of intact lomefloxacin and ciprofloxacin in the presence of their acid degradation products

A reversed phase HPLC method was developed for the determination of lomefloxacin and its degradation product. In addition, two other methods have been developed for the determination of lomefloxacin hydrochloride [LF.HCl] and ciprofloxacin hydrochloride [CF.HCl] in presence of their acid induced degradation products. For the reversed phase HPLC method [determination of LF.HCl], the mobile phase used was a mixture of water: acetonitrile: triethylamine [80:20:0.6, v/v/v] adjusted to pH 3.0 with o-phosphoric acid. The flow rate was 1.5 ml/min. and the detection was carried out at 328 nm. The linearity range was found to be 0.5-6 micro g / 20 micro l for LF.HCl. The limits of detection and quantification [LOD and LOQ] were 0.22 micro g / 20 micro l and 0.74 micro g / 20 microl respectively. The second method was densitometric method for the determination of both LF.HCl and CF.HCl, the developing system used was a mixture of methanol and ammonia buffer [80:20, v/v]. Detection was carried out at 288 nm and 279 nm. for intact LF.HCl and CF.HCl respectively. The linearity ranges were found to be 1-6 micro g / 10 microl and 0.25-2.5 micro g / 10 microl for intact LF.HCl and CF.HCl respectively. LOD and LOQ were 0.1, 0.34 micro g/10 microl and 0.05, 0.18 micro g /10 microl for both drugs, respectively. The third method was derivative spectrophotometric method for the determination of [LF.HCl] and [CF.HCL]. The linearity ranges were found to be 2-8 micro g/ml and 5-12 micro g/ml for LF.HCl and CF.HCl respectively. LOD and LOQ were 0.39 micro g, 1.29 micro g/ml and 1.03, 3.45 micro g/ml for LF.HCl and CF.HCl respectively. Separation and identification of the acid degradation products of lomefloxacin hydrochloride and ciprofloxacin hydrochloride were carried out. The three described methods proved to be sensitive, precise and applicable to both dosage forms and laboratory prepared mixtures of the intact drugs and their acid degradation products

Determination of nortriptyline hydrochloride and fluphena-zine hydrochloride in motival tablets

Accurate and sensitive methods were proposed for the determination of nortriptyline hydrochloride and fluphenazine hydrochloride in mixture. The first method based on first derivative spectrophotometric procedure. Nortriptyline hydrochloride was determined by zero crossing measurements at 255.5 nm. The ordinate value at 262.5 nm was used to calculate the amount of fluphenazine hydrochloride in mixture. An alternative evaluation of both drugs in mixture involved the use of sodium 1,2-naphthoquine-4-sulfonate as a colorimetric reagent for the selective determination of nortriptyline hydrochloride and a fluorimetric method for the determination of fluphenazine hydrochloride alone. The presented methods were successfully applied on laboratory made mixtures and motival tablets. The described methods were compared with official methods for the determination of both drug [1,2]

Determination of some benzodiazepines using N-bromosuccinimide: part I-litrimetric methods

Diazepam, lormetazepam, chlorodemethyldiazepam and lorazepam representing 1,4-benzodiazepines are quantified using N- bromosuccinimide after being hydrolyzed in aqueous hydrochloric or sulfuric acids. The stoichiometry of the reaction is ascertained in each medium. Clobazam, a 1,5-benzodiazepine, is estimated by reaction of the intact drug in 1: 9 DMF/4 M HCl with N-bromosuccinimide. The methods presented are successfully applied for the determination of the aforementioned drugs in their pharmaceutical formulations

Determination of some benzodiazepines using N-bromosuccinimide: part II: spectrophotometric methods

A spectrophotometric determination of diazepam and lormetazepam based on measuring the absorbance of the corresponding benzophenones N- bromosuccinimide reaction products is presented. The method is capable of determining hydrolyzed diazepam or lormetazepam when present in mixture with the intact drug. The methods presented are successfully applied for the determination of the aforementioned drugs in their pharmaceutical formulations

Spectrofluorometric determination of loramet tablets

A sensitive and selective spectrofluorometric assay for lormetazepam in tablets is proposed. The method is based upon the acid hydrolysis of the drug in concern prior to cyclization of the produced benzophenone to a fluorescent acridanone derivative. The assay offers more selectivity than the spectrophotometric method