The purpose of this work was to develop accurate, sensitive, specific and precise analytical methods for analysis of some drugs used for the treatment of some geriatric disorders, namely; Empagliflozin, Ivabradine Hydrochloride, Linagliptin, Nebivolol Hydrochloride, Trospium Chloride and Valsartan. The thesis consists of four parts: Part (I): General Introduction and Literature Review (Part I) includes pharmacological actions of the selected drugs, their chemical and physical properties and literature review over the published methods for their determinations alone or in mixtures, in pharmaceutical products or in biological fluids Part (II): Spectrophotometric determination of some drugs in mixtures This part is divided into three chapters: Chapter (I): Different spectrophotometric methods for simultaneous determination of Nebivolol HCl and Valsartan mixture by univariate methods In this chapter, five methods were used for simultaneous determination of Valsartan and Nebivolol Hydrochloride mixture such as: Ratio Difference method, Derivative Ratio method, Mean Centering of the ratio spectra, Bivariate spectrophotometric method and H-Point Standard Additions spectrophotometric method. These methods were successfully applied for determination of this mixture in pure form and in its pharmaceutical preparation. All results were compared with those of the reported method and no significant variation was detected. Chapter (II): Spectrophotometric methods for simultaneous determination of Nebivolol HCl and Valsartan mixture by multivariate methods Appropriate and effective two multivariate chemometric methods (PLS and PCR) were developed for simultaneous determination of NEB and VAL in their pure forms and in pharmaceutical preparations. All results were compared with those of the reported method and no significant variation was detected. Chapter (III): Different spectrophotometric methods for simultaneous determination of Empagliflozin and Linagliptin mixture In this chapter, four methods were applied for simultaneous determination of Linagliptin and Empagliflozin such as Ratio Difference method, Derivative Ratio method, Dual wavelength method and Mean Centering of the ratio spectra. These methods were effectively used for determination of this mixture in pure form and in its pharmaceutical formulation. All results were compared with those of the reported method and no significant difference was identified. Part (III): Chromatographic Methods This part is divided into three chapters Chapter (I): Thin layer chromatographic method for simultaneous determination of Nebivolol Hydrochloride and Valsartan mixture In this chapter, a simple TLC method was developed for simultaneous estimation of NEB and VAL. Chromatographic separation was achieved by using (Methanol: Chloroform: Toluene: Ammonia (3: 2: 9:0.2)) as a mobile phase and spots were scanned at 285 nm for densitometric determination. The obtained method can be successfully used for assessment of NEB and VAL in their bulk powders and in pharmaceutical dosage form. Statistical comparison between results acquired by the suggested method and those gained by the reported method presented no any significant alterations. Chapter (II): High Performance Liquid Chromatographic (HPLC) method for determination of Nebivolol Hydrochloride and Valsartan mixture in their pure forms, in pharmaceutical preparation and in human plasma In this chapter, a simple and sensitive HPLC method was developed for quantitative determination of NEB and VAL in their pure forms, in pharmaceutical preparation and in human plasma. Optimum separation was achieved on a Kinetex 2.6 C18 column 100A (4.6-mm × 100-mm), mobile phase consisting of Propanol and 0.5 M Potassium dihydrogen orthophosphate buffer, adjusted pH 7 by triethylamine and at flow rate 1 mL/min with UV detection at 220 nm. Statistical comparison between results obtained by the adopted method and that obtained by the reported method showed no significant variations. Chapter (III): Thin layer chromatographic method for simultaneous determination of Empagliflozin and Linagliptin mixture This chapter is concerned with production of a TLC method for simultaneous determination of EMPA and LINA mixture. Chromatographic separation was developed by using (Methanol: Chloroform: Acetic acid (6: 4: 0.2 by volume)) and spots were scanned at 225 nm for densitometric determination. The obtained method was successfully utilized for assessment of EMPA and LINA in their pure forms and in pharmaceutical dosage preparation. Statistical comparison between results acquired by the developed methods and those gained by the reported method illustrated no any significant variations. Part (IV): Conductometric methods This part is divided into two chapters Chapter (I) : Conductometric determination of Trospium chloride by Silver nitrate and Phosphomolybdic acid Two simple conductometric methods were developed for determination of Trospium chloride in pure form and in pharmaceutical preparation. The methods were based on utilizing two precipitating reagents; Silver nitrate (AgNO3) and Phosphomolybdic acid (PMA).The linearity range was 2.5-14.5 mg of pure Trospium chloride for Silver nitrate and 4.5-14.5 mg for PMA. Statistical comparison between results acquired by the developed methods and those gained by the reported method showed no any significant variations. Chapter (II): Conductometric determination of Ivabradine Hydrochloride by Silver nitrate, Phosphomolybdic acid and Ammonium Renickate. Three valid conductometric methods were developed for determination of Ivabradine Hydrochloride in its pure form and in pharmaceutical preparation. The methods were based on utilizing three precipitating reagents; Silver nitrate (AgNO3), Phosphomolybdic acid (PMA) and Ammonium renickate. The linearity range was (5 - 17.5) mg of pure Ivabradine Hydrochloride for Silver nitrate, PMA and Ammonium renickate. Statistical comparison between results acquired by the developed methods and those gained by the reported method illustrated no any significant variations.