The optimization and validation of sequential injection analysis and sequential injection chromatography methods for some pharmaceuticals

The family of flow injection (FI) techniques includes three generations, flow injection analysis (FIA), sequential injection analysis (SIA), and bead injection analysis (BIA). In addition, new versions of SIA, micro-sequential injection-lab-on-valve (μSIA-LOV), and sequential injection chromatography (SIC), have recently been developed. The current study reports the development of four methods for the assay of some pharmaceuticals utilizing flow injection techniques. The methods were validated based on guidelines recommended by the international union of pure and applied chemistry and were then applied to real pharmaceutical samples. The first method was applied for diclofenac assay in various pharmaceutical formulations including tablets, injections and gel. The method was validated and applied to pharmaceutical formulations (tablets, injection and gel). It is recommended to critically optimize effective and interacting conditions using other such optimization tools as response surface and simplex, rather than factorial design that used at initial optimization stage. In the second method a developing oxidation reaction for chlorpromazine by permanganate in acidic media was adopted. Then the method was validated and realized by a British pharmacopoeia methods. It had advantage of high rapidity and was also reagent saving and environmental safety. In the third method, lisinopril (LSP) and hydrochlorothiazide (HCZ) were successfully separated and quantified in tablet formulation using reversed-phase sequential injection liquid chromatography (SIC) coupled with a miniaturized fiber optic spectrometer. The proposed method enjoys outstanding features with respect to analysis time, reagent consumption and safety for the environment. In the fourth method, SIC was exploited for the separation and quantification of sildenafil in tablet formulation. The unique benefits of this method are inexpensive instrumentation, high rapidity, and reagent saving and thus better safety for the environment. The proposed SIA and SIC methods were found to be accurate and reproducible, with respect to sample frequency, reagent saving, safety in handling, automation, selectivity and precision, when the result were statistically compared with the results obtained by official BP standard methods and other non-official standard methods.