Spectrum subtraction as a complementary method for six resolution techniques resolving overlapping spectra; application to multicomponent veterinary formulation with greenness and whiteness assessment.

Mathematical filtration is an efficient tool to resolve the overlapping spectra of binary mixtures in zero or first order form. Herein, a comparative study was conducted between six economic, accurate and precise spectrophotometric methods for determination of Triclabendazole (TCB) and Levamisole HCl (LVM). Each component was resolved with minimum mathematical steps in its zero-order absorption spectrum by ratio subtraction, constant multiplication, and the recent factorized response method; coupled with spectrum subtraction. In addition, the mixture was resolved in its first derivative form by derivative subtraction, D1 constant multiplication, and the recent D1 factorized response method; coupled with spectrum subtraction. Results obtained were also compared to those obtained from constant value, concentration value, and derivative ratio methods. The linearity range was found to be either 1.0-10.0 µg/mL or 2.0-20.0 µg/mL for TCB, and 2.0-14.0 µg/mL for LVM with LOD of 0.08 µg/mL and 0.19 µg/mL, respectively. Validation of the proposed methods was performed according to VICH guidelines. Results obtained from the statistical data showed no significant difference regarding accuracy and precision compared to the reported methods. The developed spectrophotometric methods followed the principles of green analytical chemistry, in which the green assessment was done through four tools, called, National Environmental Methods Index (NEMI), Analytical Eco-Scale (AES), Green Analytical Procedure Index (GAPI) and Analytical greenness metric (AGREE). Also, a white assessment was performed using RGB model. The proposed methods could offer an economic alternative for the routine analysis of bulk materials and combined veterinary dosage form.

Novel eco-friendly spectrophotometric approaches for resolution of fixed dose formulation of phenylbutazone with minor component of dexamethasone: Greenness assessment by AGREE tool.

Spectrophotometric resolution of severely overlapped binary mixtures with minor component is challenging. Herein, coupling of mathematical manipulation steps with sample enrichment was conducted on the binary mixture spectrum of Phenylbutazone (PBZ) and Dexamethasone sodium phosphate (DEX) to resolve, for the first time each component separately. Simultaneous determination of both components in a mixture ratio of 1:0.002 was achieved in their zero or first order spectra by the recent factorized response method along with ratio subtraction and constant multiplication methods; all coupled with spectrum subtraction. In addition, a novel second derivative concentration value and second derivative constant value methods were developed for PBZ determination. The concentration of the minor component DEX was obtained, without preliminary separation steps by derivative ratio after sample enrichment by either spectrum addition or standard addition. Spectrum addition approach showed superior characteristics compared to standard addition technique. All proposed methods were placed through a comparative study. Linear correlation was found to be 1.5-18.0 µg/mL for PBZ, and 4.0-45.0 µg/mL for DEX. The proposed methods were validated in accordance with ICH guidelines. The greenness assessment of the proposed spectrophotometric methods was evaluated by AGREE software. Results obtained from the statistical data were evaluated by comparing to one another as well as the official USP methods. These methods offer a cost and time effective platform to analyze bulk materials and combined veterinary formulation.

Mathematical Modeling for HPLC Separation and Quantification of an Anti hypertensive Combination by Response Surface Methodology.

BACKGROUND: Determination of a multi-component mixture by HPLC requires many preliminary runs for method development which is both time-consuming and expensive due to the usage of large solvent volumes. OBJECTIVE: In the present study, the main objective was to reduce the preliminary runs that are required for optimizing the method conditions and also shorten the run time of analysis to be suitable for quality control laboratories where there are a large number of samples to be analyzed. METHODS: That was achieved using a two-factor, three-level response surface experiment which is a multivariate design that predicts the significant factors for optimizing the studied responses. RESULTS: The response surface design suggests that both acetonitrile ratio and flow rate are significant factors for full resolution of the studied mixture: atenolol, amiloride, and hydrochlorothiazide. The studied mixture was fully separated and determined in less than 5 min with perfect resolution. CONCLUSION: Experimental design is a very beneficial tool for optimization of the method conditions in HPLC, especially if the studied mixture ingredients have overlapping peaks. For atenolol, amiloride, and hydrochlorothiazide, acetonitrile and flow rate were found to be the significant factors that affected the resolution of the studied mixture. HIGHLIGHTS: Response surface design is a powerful tool that could be used for predicting the significant factors for separation in HPLC. Optimization of the method conditions was done using a limited number of preliminary runs. The studied ternary mixture was fully separated in less than 5 min with the aid of experimental design.