In this dissertation, the possibilities of using capillary electrophoresis as a separation technique for the analysis of pharmaceutically active compounds are explored. Capillary electrophoresis (CE) is an analytical separation technique used to study a wide range of analytes, and it may be employed in pharmaceutical analysis. The primary reasons for employing CE over alternative liquid-based separation techniques are fast analysis time, excellent resolution, low solvent waste, and minimal sample sizes. Depending on the features of the analytes and the sample matrix, multiple modes of CE can be utilized, with capillary zone electrophoresis (CZE) being the most common. The main principle of CZE is the separation of analytes owing to variations in mobility, which is determined by the analytes' charge and size and electroosmotic flow (EOF). The research presented in this thesis aims to investigate the applicability of CE and develop CE methods for rapid and precise analysis of pharmaceutical applications. Paper I presents the development and validation of a simple CZE method for the precise determination of the first-line drug used for the treatment of multiple sclerosis, the therapeutic peptide glatiramer acetate (GA), enabling the rapid control of GA-based pharmaceuticals. In addition, the CZE methodology should separate glatiramer and amino acids L-lysine, L-alanine, L-glutamic acid, and L-tyrosine from which GA is synthesized. This separation is essential for obtaining information about the total concentration of GA and potential amino acid impurities in the final GA product. Paper II presents the development and validation of a CE method for the chiral separation of three H1-antihistamine drugs, chlorcyclizine, norchlorcyclizine, and neobenodine, using sulfated -cyclodextrin (S--CD) as the chiral selector. These compounds are studied as old drugs for new uses, such as for the treatment of Ebola, hepatitis C, Zika virus, malaria, and SARS-CoV-2. The study explores various factors influencing the separation efficiency, including cyclodextrin concentration, organic modifier content, voltage, and buffer pH. The investigation extensively explores the impact of methanol on enantiomeric resolutions. Notably, the presence of this additive has been identified as crucial for enhancing separation efficiency and achieving good enantiomeric resolution. The study sheds light on the importance of these factors in developing an effective CE method for the chiral separation of H1-antihistamine drugs.In this dissertation, the possibilities of using capillary electrophoresis as a separation technique for the analysis of pharmaceutically active compounds are explored. Capillary electrophoresis (CE) is an analytical separation technique used to study a wide range of analytes, and it may be employed in pharmaceutical analysis. The primary reasons for employing CE over alternative liquid-based separation techniques are fast analysis time, excellent resolution, low solvent waste, and minimal sample sizes. Depending on the features of the analytes and the sample matrix, multiple modes of CE can be utilized, with capillary zone electrophoresis (CZE) being the most common. The main principle of CZE is the separation of analytes owing to variations in mobility, which is determined by the analytes' charge and size and electroosmotic flow (EOF). The research presented in this thesis aims to investigate the applicability of CE and develop CE methods for rapid and precise analysis of pharmaceutical applications. Paper I presents the development and validation of a simple CZE method for the precise determination of the first-line drug used for the treatment of multiple sclerosis, the therapeutic peptide glatiramer acetate (GA), enabling the rapid control of GA-based pharmaceuticals. In addition, the CZE methodology should separate glatiramer and amino acids L-lysine, L-alanine, L-glutamic acid, and L-tyrosine from which GA is synthesized. This separation is essential for obtaining information about the total concentration of GA and potential amino acid impurities in the final GA product. Paper II presents the development and validation of a CE method for the chiral separation of three H1-antihistamine drugs, chlorcyclizine, norchlorcyclizine, and neobenodine, using sulfated -cyclodextrin (S--CD) as the chiral selector. These compounds are studied as old drugs for new uses, such as for the treatment of Ebola, hepatitis C, Zika virus, malaria, and SARS-CoV-2. The study explores various factors influencing the separation efficiency, including cyclodextrin concentration, organic modifier content, voltage, and buffer pH. The investigation extensively explores the impact of methanol on enantiomeric resolutions. Notably, the presence of this additive has been identified as crucial for enhancing separation efficiency and achieving good enantiomeric resolution. The study sheds light on the importance of these factors in developing an effective CE method for the chiral separation of H1-antihistamine drugs.