Method Development and Quantification for Some Non Pharmacopeial drugs

Abstract

Method of analysis for six different non pharmacopeial drugs was developed and the developed method was validated taken care of all criteria of validation process. The Methods were found to be highly sensitive, selective, rapid, precise, accurate and affordable which can be followed by pharmaceutical industries. For estimation of six drugs; Ticagrelor, Linagliptin, Rabeprazole, Sitagliptin, Paliperidone and Pregabalin reversed phase high performance liquid chromatography having auto-sampler and auto-injector coupled Photodiode Array (PDA) Detector was used. Analysis was performed at 250 nm, 294 nm, 280 nm, 267 nm, 280 nm and 210 nm which are the absorption maxima of Ticagrelor, Linagliptin, Rabeprazole, Sitagliptin, Paliperidone and Pregabalin, respectively. Identification of each of the drug was done with respect to certified reference standards (highest available purity) and quantitation using external calibration curves of the respective certified standards. Linearity of the drugs was calculated from calibration curve of five different concentration levels of reference standard samples of the six drugs. Excellent linearity of Ticagrelor, Linagliptin, rabeprazole, sitagliptin, paliperidone and pregabalin was observed with correlation coefficient (r ) 0.9997, 0.9993, 0.9990, 0.9997, 0.9995 and 0.9999, respectively. Sensitivity i.e. LOD & LOQ were calculated from S/N ratio 3:1 and 10:1, respectively. For estimation, 18 experiments were carried out at different solvent compositions, pH of buffers, flow rate and column oven temperatures. All the experimental data were analyzed by Minitab software and optimal experimental conditions for analysis in terms of solvent compositions, pH of the buffer, flow rate and column oven temperature were found for each of the drugs taking into account of retention times, peak purity and theoretical plates. Optimized conditions were used for recovery experiments and method validations. The validated method was used for quantitation active ingredients in the locally produced drugs in dosage form and innovator`s drugs. Placebo of the each of the drugs was made separately by mixing their respective excipients and placebos were spiked with reference standards of three different concentration levels and three replicate studies were made; average (%) Recovery, Standard Deviations, and percent Relative Standard Deviations (% RSD) were calculated from the nine experiments. LOD and LOQ were found to be 0.06 & 0.22, 0.1.05 & 3.15, 3.05 & 8.72, 1.17 & 3.61, 0.70 & 3.26 and 0.03 & 0.12 for ticagrelor, sitaglitin, pregabalin, linagliptin, rabeprazole and paliperidone, respectively which showed the method is highly sensitive. Average Recovery (%) and RSD (%) of Experimental results were 99.12 to 101.7 and 0.08-1.61 which are acceptable according to USP and USFDA and showed method is excellent and possesses high Accuracy. Intermediate precision of the six drugs at 3 difference concentration levels between two days were found to be 0.12-1.30 which also showed the method is highly precise. In-vitro comparison of the local non-pharmacopoeil drugs with innovator`s drugs were done to find out dissimilarity (f1) and similarity (f2). Out of two brands of ticagrelor (n=4), rabeprazole (n=5) and paliperidone (one brand is available) were found to be dissimilar. Rest of the drugs all brands were showed similar. Assay of the six drugs; one brand of ticagrelor shower lower value (~15%) than the innovator`s drugs. Having one exception all the drugs produced in Bangladesh are in International Standards which are effective for target treatments in local and overseas countries.