Determination of promethazine by its inhibition of the chemiluminescence of the luminol—hydrogen peroxide—chromium(III) system

Portable system of programmable syringe pump with potentiometer for determination of promethazine in pharmaceutical applications

A simple and fast-automated method was developed and validated for the assay of promethazine hydrochloride in pharmaceutical formulations, based on the oxidation of promethazine by cerium in an acidic medium. A portable system, consisting of a programmable syringe pump connected to a potentiometer, was constructed. The developed change in potential during promethazine oxidation was monitored. The related optimum working conditions, such as supporting electrolyte concentration, cerium(IV) concentration and flow rate were optimized. The proposed method was successfully applied to pharmaceutical samples as well as synthetic ones. The obtained results were realized by the official British pharmacopoeia (BP) method and comparable results were obtained. The obtained t-value indicates no significant differences between the results of the proposed and BP methods, with the advantages of the proposed method being simple, sensitive and cost effective.

Determination of phenothiazines in pharmaceutical formulations and human urine using capillary electrophoresis with chemiluminescence detection

A CE instrument coupled with chemiluminescence (CL) detection was designed for the determination of promethazine hydrochloride (PTH) and promazine hydrochloride (PMH) in real samples. An important enhancement of the CL emission of luminol with potassium ferricyanide was observed in the presence of these phenothiazines; so this system was selected for their detection after CE separation. Parameters affecting the electrophoretic separation were optimized in a univariate way, while those affecting CL detection were optimized by means of a multivariate approach based on the use of experimental designs. Chemometrics was also employed for the study of the robustness of the factors influencing the postcolumn CL detection. The method allows the separation of the phenothiazines in less than 4 min, achieving LODs of 80 ng/mL for PMH and 334 ng/mL for PTH, using sample injection by gravity. Electrokinetic injection was used to obtain lower LODs for the determination of the compounds in biological samples. The applicability of the CE-CL method was illustrated in the determination of PTH in pharmaceutical formulations and in the analysis of PMH in human urine, using a previous SPE procedure, achieving an LOD of 1 ng/mL and recoveries higher than 85%.

Determination of phenothiazine derivatives by high performance thin-layer chromatography combined with densitometry

A high performance thin-layer chromatography (HPTLC) method combined with densitometry for determination of phenothiazine derivatives is described. Quantitation was performed in reflectance mode by using a computer-controlled densitometer Desaga CD 60. Established calibration curve (r > 0.999), precision (RDS values: 0.95-2.53%), detection limits as well as recovery values (101.1-102.8%) were found to be satisfactory. The presented method is rapid, precise and sensitive, and may be alternative to traditionally used HPLC. The method has been successfully applied in the analysis of pharmaceutical formulations.

Resonance Rayleigh Scattering for the Determination of Chlorpromazine and Promethazine

Chlorpromazine (CPZ) and promethazine (PZ) can react with potassium ferrioxalate (PF) to form 3:1 ion-association complexes, which can result in a significant enhancement of resonance Rayleigh scattering (RRS) intensity. The maximum scattering peaks are located at 368 nm for CPZ-PF and 370 nm for PZ-PF. The RRS spectroscopic characteristics, the optimum conditions of reactions, and influencing factors have been studied for CPZ-PF and PZ-PF. There is a linear relationship between the RRS intensity and the drug concentration in the range of 0.02–8.00 μg mL–1 for CPZ and 0.04–9.00 μg mL–1 for PZ, and the detection limits (3σ) are 6.6 ng mL–1 for CPZ and 10.6 ng mL–1 for PZ. The proposed method has been applied to determine CPZ in urine and serum samples with satisfactory results. Moreover, the reaction mechanism and the reasons for intensity enhancement of RRS have been discussed.

Flow-chemiluminescence: a growing modality of pharmaceutical analysis

The present article deals with a review of the applications of the chemiluminescence to pharmaceutical analyses by using continuous-flow assemblies. A comprehensive study on the fundamentals of the chemiluminescence is also included.

Chemiluminescence determination of thioridazine hydrochloride by flow-injection analysis

Hydrogen peroxide, potassium permanganate, potassium dichromate, potassium hexacyanoferrate(III), cerium(IV) sulphate and sodium peroxidisulphate have been tested as potential reagents for chemiluminescence generation from the oxidation of phenothiazine derivatives. Only with potassium permanganate in acidic medium were satisfying results achieved. A total of 13 different phenothiazine derivatives produce luminescence of different intensities on oxidation. Thioridazine hydrochloride was chosen to develop a rapid and simple method for its determination in pharmaceutical formulations. The limit of detection is 1.2 x 10(-6) mol l(-1), and 110 samples per hour can be determined.

Chemiluminescence in drug assay

The phenomenon of chemiluminescence allows the development of simple analytical procedures using low cost instrumentation which can be easily controlled by computers. The sensitivity of the methods is excellent, and selectivity is improved by high-performance liquid chromatographic separation. A broad area of chemiluminometric applications is drug analysis, which is reviewed in this paper.