الفهرس 
General IntroductionOnly 14 pages are availabe for public view
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Abstract
This thesis presents new optical sensors based on silver nanoparticles for determination of some non-chromophoric drugs either in bulk form or in their pharmaceutical dosage forms. The drugs selected for this study are: pregabalin, glucosamine, alendronate, and tobramycin. It consists of five parts: Part I This part describes a general introduction about nanoparticles and their unique optical properties. Then, it discusses the different approaches that can be employed for the development of silver nanoparticles-based optical sensors including spectrophotometric, scattering, spectrofluorimetric and chemiluminescence sensors. Part II This part deals with the development and validation of a colorimetric method for naked eye detection and quantitative determination of pregabalin based on nanoparticle aggregation with subsequent changes in the localized surface plasmon resonance band of silver nanoparticles. The method was linear over the concentration range of 100 – 500 μg mL−1. This work involves the following: • Optimization of the experimental conditions Silver nanoparticles were synthesized via reduction of silver nitrate by sodium borohydride using 10 mM citrate as a stabilizer. Pregabalin was prepared in 1.0 M acetate buffer (pH 3.8). Silver nanoparticles solution was diluted to 0.2 mM, then it was allowed to react with pregabalin for 6 minutes before recording the UV-visible spectra. • Application to pharmaceutical dosage form The proposed method was successfully applied for determination of pregabalin in its capsules with no interference from excipients. The mean % recovery ± SD was found to be 97.809 ± 1.396. Part III It presents a validated spectrophotometric method for naked eye detection and quantitation of glucosamine in bulk and in capsules. The method is based on using glucosamine as reducing agent during nanoparticle synthesis and measuring the intensity of the localized surface plasmon resonance band of silver nanoparticles which is proportional to glucosamine concentration in the range 1 – 9 μg mL−1. This study includes: • Optimization of the experimental conditions Silver nanoparticles were synthesized via reduction of 0.02 M silver nitrate by glucosamine using 0.1% polyvinylpyrrolidone as a stabilizer in the presence of 0.075 M ammonium hydroxide. The reaction mixture was heated at 90 °C for 5 minutes. • Application to glucosamine capsules The method was applied for determination of glucosamine in its commercially available capsules. The mean % recovery ± SD from glucosamine capsules was found to be 101.789 ± 1.068 with no interference from excipients. Part IV This part presents a new optical sensor based on the localized surface plasmon resonance and resonance light scattering of silver nanoparticles for naked eye detection and quantitation of alendronate in bulk and in pharmaceutical dosage forms over the concentration range 0.2 – 0.9 μg mL−1. This work involves: • Optimization of the experimental conditions Silver nanoparticles were synthesized by reducing silver nitrate with borohydride using citrate as a stabilizer. Alendronate was prepared in 10 mM citric acid and allowed to react with undiluted silver nanoparticle colloidal solution for 5 minutes before recording UV-visible and light scattering spectra. • Application to pharmaceutical dosage form The proposed methods were successfully applied for analysis of alendronate in its tablets with no interference from excipients. The mean % recovery ± SD was found to be 97.407 ± 1.759 for the spectrophotometric method and 98.256 ± 1.346 for the light scattering method. Part V It presents the use of silver nanoparticles as spectrophotometric and spectrofluorimetric probe for determination of tobramycin. The spectrophotometric method was based on nanoparticle aggregation while the spectrofluorimetric method was based on the ability of tobramycin to restore the fluorescence of fluorescein after it had been quenched by silver nanoparticles. This work involves: • Optimization of the experimental conditions Silver nanoparticles were synthesized by reducing 0.1 mM silver nitrate with borohydride without using a stabilizer. The freshly prepared nanoparticles colloidal solution was allowed to stand for 15 minutes, then it was mixed with fluorescein. Afterwards, tobramycin was added and allowed to react for 10 minutes before recording UV-visible and fluorescence spectra. • Application to pharmaceutical dosage form The proposed methods were successfully applied for determination of tobramycin in its ophthalmic solution with no interference from excipients. The mean % recovery ± SD was found to be 99.036 ± 1.737 for the spectrophotometric method and 101.192 ± 1.315 for the spectrofluorimetric method. For all the proposed methods described in the previous parts, the statistical analysis of the results including the derivation of the regression equations for the different calibration curves, accuracy, precision, limits of detection and quantitation and selectivity have been carried out. The thesis contains 48 tables, 43 figures, and 210 references in addition to the English summary and Arabic summary.