Potentiometric Response of Modified Carbon Paste Electrode Based on Mixed Ion‐Exchangers

A new chemically modified carbon paste electrode based on a mixture of two ion‐exchangers namely chlorpheniramine‐silicotungstate (CPM‐ST) and chlorpheniramine‐tetraphenylborate (CPM‐TPB) as ion‐exchange site for determination of chlorpheniramine maleate (CPM) was described. The best performance was exhibited by the electrode having the paste containing 3.0 wt% ion‐exchangers (CPM‐ST&CPM‐TPB), 48.5 wt% graphite, 47.5 wt% DOPh and 1.0 wt% NaTPB. The proposed chemically modified carbon paste electrode exhibited a Nernstian response for CPM over a wide concentration range of 1.2×10^?6 to 1.0×10^?2 M with a detection limit of 5.1×10^?7 M between pH 4.5 and 7.7 with fast response ≤10 s. The sensor showed good selectivity for CPM with respect to a large number of inorganic cations, organic cations, sugars, amino acids and some common drug excipients. The modified electrode was applied to potentiometric determination of CPM in its pharmaceutical preparations and biological fluids (serum and urine) with average recoveries of 97.5–102% and relative standard deviations of 0.32–1.97%.     

Simultaneous Quantitative Determination of Codeine Phosphate,Chlorpheniramine Maleate Phenylephrine Hydrochloride and Acetaminophen in Pharmaceutical Dosage Forms Using Thin Layer Chromatography Densitometry

Abstract

A simple and specific method for the analysis of codeine phosphate, chlorpheniramine maleate, phenylephrine hydrochloride and acetaminophen in pharmaceutical dosage forms was developed. The procedure consists of direct application of diluted liquid dosage forms and the solutions of solid dosage forms on silica gel plates. The mobile phase for development consisted of n-butanol-methanol-toluene-water and acetic acid. The separated components were measured quantitatively by densitometry. Linearity, reproducibility and percentage recovery of active ingredients from dosage forms were calculated.     

The Use of First-Order UV Spectroscopy to Determine Binary Mixtures of Pharmaceuticals (A) PHEH and CBOM and (B) DPHH and NPZH

Abstract

Procedures were developed for the simultaneous determination of pharmaceuticals in two-component commercial formulations by first-order derivative UV spectrophotometry. Phenylephrine hydro chloride and carbinoxamine maleate in capsules and diphenhydramine hydrochloride and naphazolixehydro hydrocloride in nasal gelly were succesfully assayed. A simple sensitive method in the usual range for the binary preparations has been developed. Average recoveries of the four compounds in the formulations under study were 100.04 ± 1.28% 101.50 ± 2.27 %, 101.59 % 1.24 % and 100.49 ± 2.59 %.     

Synthesis and Characterization of a Cobalt Complex with Maleate and Pyridine

A new polymeric cobalt complex [Co(u-male)(py)(H2O)]n (male=maleate; py =pyridine) 1 was prepared by cobalt chloride hexahydrate with disodium maleate and pyridine in an alcohol-aqueous solution. Single-crystal X-ray analysis has revealed that 1 crystallizes in the orthorhombic system, space group Pnma with a=18.001(1), b=7.6001(6), c=7.4731(6) A, V=1022.4(1)A3, Z=4, C9H9CoNO5, Mr=270.10, Dc= 1.755 g/cm3, F(000)=548, μ(MoKa)=1.683 mm-1, S =1.002, the final R=0.0280 and wR=0.0746 for 883 observed reflections with I ＞ 2σ(I). The structure analysis shows an approximate octahedral coordination environment of metal center. The Co(Ⅱ) ions are bridged by maleic anions in a rare tetradentate coordination fashion with a syn-anti coplanar conformation of the carboxyl group, forming a two-dimensional corrugated 2-D structure which is further attached into a three-dimensional framework via non-classical C-H…O interactions between adjacent layers.