A dissolution method with robust high performance liquid chromatographic （HPLC） analysis for im- mediate release tablet formulation was developed and validated to meet the requirement as per Inter- national Conferen...A dissolution method with robust high performance liquid chromatographic （HPLC） analysis for im- mediate release tablet formulation was developed and validated to meet the requirement as per Inter- national Conference on Harmonization （ICH） and United States Food and Drug Administration （USFDA） guidelines. The method involved the use of Agilent ZORBAX Eclipse XDB C18 column, and temperature was maintained at 30 ℃. After optimization, the mobile phase was selected as phosphate buffer （KH2PO4, 30 mM） ： ACN （60：40, v/v） with pH 3.0, and retention time Rt was found as 3.24, 4.16, and 2.55 min for paracetamol （PCM）, chlorpheniramine maleate （CPM） and phenylephrine hydrochloride （PH） respec- tively at 265 nm and at a flow rate of 1 mL/min. The relative standard deviation （%RSD） for 6 replicate measurements was found to be less than 2%. Furthermore net analyte signal standard addition method （NASSAM） with spectrophotometer was performed for standard and liquid oral suspension. On the basis of selectivity, sensitivity and accuracy analysis, it was confirmed that this novel method could be useful for simultaneous estimation of the given drug combinations. Two-way analysis of variance （ANOVA） was applied for evaluating the statistical difference between the assay results obtained via both NASSAM and RP-HPLC methods and ultimately no significant difference was found between both the methods. All the methods and results were acceptable and confirmed that the method was suitable for intended use.展开更多
A method to separate a harmonic signal from multiplicative and additive noises is proposed. The method is to square the signal x(t), which consists of a harmonic signal embedded in multiplicative and additive noises, ...A method to separate a harmonic signal from multiplicative and additive noises is proposed. The method is to square the signal x(t), which consists of a harmonic signal embedded in multiplicative and additive noises, to form another signal y(t) = x2(t)-E[x2(t)]. After y(t) having been gotten, the Fourier transform is imposed on it. Because the information of x(t) (especially about frequency) is included in y(t), the frequency of x(t) can be estimated from the power spectrum of y(t). According to the simulation, under the condition where frequencies divided by resolution dω are integer, the maximum relative error of estimated frequencies is less than 0.4% when the signal-to-noise ratio (SNR) is greater than -23 dB. If frequencies divided by resolution dω are not integer, the maximum relative error will be less than 2.9%. But it is still small in terms of engineering.展开更多
文摘A dissolution method with robust high performance liquid chromatographic （HPLC） analysis for im- mediate release tablet formulation was developed and validated to meet the requirement as per Inter- national Conference on Harmonization （ICH） and United States Food and Drug Administration （USFDA） guidelines. The method involved the use of Agilent ZORBAX Eclipse XDB C18 column, and temperature was maintained at 30 ℃. After optimization, the mobile phase was selected as phosphate buffer （KH2PO4, 30 mM） ： ACN （60：40, v/v） with pH 3.0, and retention time Rt was found as 3.24, 4.16, and 2.55 min for paracetamol （PCM）, chlorpheniramine maleate （CPM） and phenylephrine hydrochloride （PH） respec- tively at 265 nm and at a flow rate of 1 mL/min. The relative standard deviation （%RSD） for 6 replicate measurements was found to be less than 2%. Furthermore net analyte signal standard addition method （NASSAM） with spectrophotometer was performed for standard and liquid oral suspension. On the basis of selectivity, sensitivity and accuracy analysis, it was confirmed that this novel method could be useful for simultaneous estimation of the given drug combinations. Two-way analysis of variance （ANOVA） was applied for evaluating the statistical difference between the assay results obtained via both NASSAM and RP-HPLC methods and ultimately no significant difference was found between both the methods. All the methods and results were acceptable and confirmed that the method was suitable for intended use.
基金the National Natural Foundation of China(No.59635140).
文摘A method to separate a harmonic signal from multiplicative and additive noises is proposed. The method is to square the signal x(t), which consists of a harmonic signal embedded in multiplicative and additive noises, to form another signal y(t) = x2(t)-E[x2(t)]. After y(t) having been gotten, the Fourier transform is imposed on it. Because the information of x(t) (especially about frequency) is included in y(t), the frequency of x(t) can be estimated from the power spectrum of y(t). According to the simulation, under the condition where frequencies divided by resolution dω are integer, the maximum relative error of estimated frequencies is less than 0.4% when the signal-to-noise ratio (SNR) is greater than -23 dB. If frequencies divided by resolution dω are not integer, the maximum relative error will be less than 2.9%. But it is still small in terms of engineering.
