Figure 3 - uploaded by Samuel Asare-Nkansah
Content may be subject to copyright.
Representative Chromatograms of Paracetamol Caffeine and Candidate Surrogate Reference Standards. The Samples in 'a' and 'b' were Co-eluted from Respective Homogenous Stocks. 'c' was Obtained from a Solution of Phenacetin Only
Source publication
Purpose: Compounds chemically related to analyte as surrogate reference standards in quantitative HPLC and the impact of internal standard on such applications have been investigated. Method: A simple reversed-phase isocratic HPLC method with UV detection was developed and validated. The solutes were paracetamol (principal analyte), caffeine (inter...
Contexts in source publication
Context 1
... 2 demonstrated that variations in concentration of principal analyte (low, medium and high) did not produce significant change in surrogate constant for each of the candidate surrogate reference compounds. In Figure 3, the selectivity of the proposed method was evidenced by the representative chromatograms. It is clear from the chromatograms that the analytical conditions could separate and resolve reasonably the study samples. ...
Context 2
... various pure samples gave values between 3.5 and 4.0 (Table 4) demonstrating that, the respective concentrations of samples were within limits of linearity of their calibration curves. The representative chromatograms in Figure 3 also provide the extent of selectivity of the analytical procedure for the samples used in the study. All the samples were reasonably resolved with no overlapping bands. ...
Similar publications
Background
A novel rapid, accurate, and stability-indicating reversed-phase high performance liquid chromatographic (RP-HPLC) and first derivative spectrophotometric determination were explained for the assay of vortioxetine (VRT) in bulk and pharmaceutical formulations. For RP-HPLC method, optimal separation and determination of VRT were achieved...
Citations
... In an attempt to overcome the limitation of lack of regular access to CRS in drug analyses and to strengthen cost effective management of the quality of pharmaceuticals in Sub-Saharan Africa, we had in a preliminary study [5] examined the use of compounds chemically related to target analytes as surrogate reference standards in quantitative HPLC. In this context, a suitable surrogate reference standard should be physicochemically similar to the analyte of interest. ...
... The RP-HPLC procedure should simultaneously elute, identify and quantify both the target analyte and surrogate reference standard (pure compound of either analytical or pharmaceutical grade) without interference from either of them. By physicochemical similarity, we had reported that a surrogate reference standard should have similar solubility and detection properties as analyte of interest with a demonstration of linear response between concentration and a measurable physical property of the analyte of interest [5]. ...
... Nominal concentrations are usually prepared from the strength of product indicated on the label and the assay value is obtained by expressing as a percentage, the ratio of the actual to nominal concentrations of the medicinal sample being analysed. We have already reported the assay of brands of paracetamol tablets with surrogate reference standards [5]. ...
To improve the efficiency of medicines quality monitoring in developing countries by reducing the limitations of lack of regular access to chemical reference standards(CRS) and corresponding financial burden, a new approach of using readily available compounds, physico-chemically related to the active pharmaceutical ingredient (API) as surrogate reference standards in reverse-phase HPLC (RP-HPLC) assays has been reported. Isocratic RP-HPLC methods were designed and validated for 7 APIs, using their respective reference standards and compounds designated as candidate surrogate reference standards to determine 'surrogate constants' (S �) for each of the surrogate reference standards with respect to a particular API. 35 pharmaceutical products containing the different APIs from 23 manufacturing outfits (foreign & local) were assayed with the surrogate reference standards, putting the S � into a previously reported equation to determine the percentage content of the test samples. Assay results from the proposed method were compared statistically with standard methods of the British Pharmacopoeia (BP 2007) and the International Pharmacopoeia (IP 2011) where appropriate. All the pharmaceutical products were successfully assayed with surrogate reference standards and the assay results were statistically comparable with those of the BP 2007 and IP 2011. Eleven compounds (11) of either analytical or pharmaceutical grade were used as surrogate reference standards for the 7 APIs with each API having more than one compound as surrogate reference standard. Some compounds could serve as surrogate reference standards (ascorbic acid, benzoic acid, paracetamol, piroxicam and metronidazole) for other APIs as well.
