Samah Abo El Abass

Development and Validation of Spectrophotometric and Pre-column Derivatization HPLC Method for Determination of Famotidine in Pharmaceuticals by Reaction with Sodium Nitroprusside; Application to Combined Tablets

Spectrophotometric and HPLC methods for estimation of famotidine in pharmaceutical formulations through derivatization with sodium nitroprusside were developed. The spectrophotometric method is based on measuring the red color formed after the reaction with sodium nitroprusside at 498 nm. The formed product was further determined by HPLC method using C18 column, mobile phase composed of methanol and 0.05 M phosphate buffer (30:70, v/v) with apparent pH 4, The UV detection was at 498 nm. Both methods were linear covering concentrations of 20-500 μg/mL. The selectivity and the simplicity of the methods allow the successful estimation of famotidine in its pharmaceuticals and in its combined tablets with ibuprofen, domperidone, paracetamol and diclofenac without interferance.

Isocratic RP-HPLC method for separation and simultaneous determination of ternary mixture of omeprazole, tinidazole and doxycycline in their raw materials and combined capsules

A simple, sensitive and rapid isocratic HPLC method has been developed for simultaneous estimation of a ternary mixture of omeprazole, tinidazole and doxycycline in both their raw state and combined in capsules, to be used for treatment of Helicobacter pylori . The analysis was performed on a C18 column (250 mm × 4.6 mm i.d., 5 μm particle size) with a mobile phase consisting of methanol and 0.06 M sodium dihydrogen phosphate (65 : 35, v/v) adjusted to pH 4.5. The UV detector was operated at 260 nm and the effluents were pumped with a flow rate of 1.0 mL min−1 using floctafenine as internal standard. The run time under the optimum chromatographic conditions is less than 6 min. Linearity, accuracy and precision were found to be acceptable over the concentration range of 2–20 μg mL−1 for omeprazole, 5–60 μg mL−1 for tinidazole and 5–30 μg mL−1 for doxycycline. The sensitivity of the method allows the determination of the studied drugs with a limit of quantification of 1.2 μg mL−1, 1.96 μg mL−1 and 1.88 μg mL−1 for omeprazole, tinidazole and doxycycline respectively. The proposed method was fully validated according to ICH guidelines. The high sensitivity and the simplicity of the proposed method allow the successful determination of such a ternary mixture in a combined capsule with a percentage recovery of 99.61% ± 0.79 for omeprazole, 99.69% ± 0.65 for tinidazole and 99.62% ± 0.94 for doxycycline.

Development and Validation of HPLC Method for Simultaneous Estimation of Famotidine, Paracetamol and Diclofenac in their Raw Materials and Pharmaceutical Formulation

Abstract A simple, sensitive and rapid HPLC method has been developed for simultaneous estimation of a ternary mixture of famotidine, paracetamol and diclofenac in their raw materials and pharmaceutical formulations. The analysis was performed on C8 column (250 mm × 4.6 mm i.d., 5-μm particle size) with mobile phase consisted of methanol and 0.01 M sodium dihydrogen phosphate (80:20, v/v) with apparent pH 3.5. The UV detector was operated at 280 nm and the effluents were pumped with flow rate of 1.0 mL/min using felodipine as internal standard. The run time under the optimum chromatographic conditions is less than 6 min. Linearity, accuracy and precision were found to be acceptable over the concentration range of 5-100 μg/mL, 10-300 μg/mL and 5-100 μg/mL for famotidine, paracetamol and diclofenac respectively. The sensitivity of the method allows the determination of the studied drugs with limit of quantification of 3.22 μg/mL, 8.93 μg/mL and 4.16 μg/mL for famotidine, paracetamol and diclofenac respectively. The high sensitivity and the simplicity of the proposed method allow the successful determination of the studied drugs in their combined tablets as well as the determination of famotidine in its dosage forms and in its combined tablets with ibuprofen. Moreover, the proposed method was fully validated according to ICH guidelines.

Simple spectrofluorimetric methods for determination of two pharmaceutically active compounds; salmeterol and trimebutine in their raw materials and pharmaceutical dosage forms in nano concentrations and testing of content uniformity

Novel, sensitive, and cost-effective spectrofluorimetric methods with fast procedures were used for the determination of salmeterol and trimebutine in their pharmaceutical dosage forms. The first method was based on measuring the native fluorescence of salmeterol in an aqueous solution at 415 nm after excitation at 245 nm. The second method was established using sodium dodecyl sulphate, SDS, as an organized medium to enhance the fluorescence of trimebutine. The enhanced fluorescence of trimebutine was traced at λem of 363 nm and λex of 265 nm. The calibration curves were constructed by plotting intensity of fluorescence versus concentration over the range of 6.0–60.0 and 7.0–70.0 ng mL−1 for salmeterol and trimebutine, respectively. The methods were perfectly implemented for the analysis of salmeterol and trimebutine in their pharmaceutical dosage forms. Furthermore, testing of the uniformity of salmeterol aerosol content was properly achieved. Moreover, validation parameters were applied according to ICH guidelines.

Derivative spectrophotometric and micellar high performance liquid chromatographic methods for simultaneous determination of silymarin and dimethyl-4,4′-dimethoxy-5,6,5′,6′-dimethylene dioxybiphenyl-2,2′-dicarboxylate (DDB) in raw materials and capsules

First derivative ultraviolet spectrophotometric and micellar high performance liquid chromatographic assay methods were developed and validated for the simultaneous determination of silymarin and dimethyl-4,4′-dimethoxy-5,6,5′,6′-dimethylene dioxybiphenyl-2,2′-dicarboxylate (DDB) in the pure form and in combined capsules. The first derivative (D1) was performed by measuring the amplitudes at 279 and 255 nm for silymarin and DDB, respectively. The calibration graphs were linear in the range of 3–40 μg mL−1 for silymarin and 3–30 μg mL−1 for DDB. An isocratic reversed phase chromatographic assay method was also developed for the determination of both drugs, a C18 column (250 mm × 4.6 mm i.d., 5 μm particle size) was used with a mobile phase composed of 0.17 M sodium dodecyl sulphate, 12% butanol and 0.3% triethylamine, all prepared in 0.02 M phosphoric acid and adjusted to pH 3.5. The flow rate was 1 mL min−1. The effluents were monitored at 288 nm and floctafenine was used as the internal standard. Plots of the peak area ratios of each drug to floctafenine were found to be linear in the range of 1–15 μg mL−1 for silymarin and 1–12 μg mL−1 for DDB. The proposed methods were validated according to ICH guidelines. The methods were successfully applied in the estimation of silymarin and DDB in their combined capsules dosage form.