Calixarene based portable sensor for the direct assay of indiscriminate ephedrine content of weight loss herbal preparations.

A novel potentiometric sensor was developed and optimized for the quantitative analysis of ephedrine in non-prescribed herbal supplements used as adjunctive therapy for weight loss. An initial optimization study aimed to reach the optimum membrane composition, sensor assembly, and experimental conditions. The study evaluated the effect of several factors on the sensor performance including different ion-exchangers, plasticizers, ionophores, membrane thicknesses, soaking solution concentrations, soaking time intervals, and pH.

Micellar liquid chromatographic determination of metformin hydrochloride using fluorimetric detection after pre-column derivatization: application to pharmacokinetic parameters in immediate and sustained release formulations.

An accurate and selective method using micellar liquid chromatography was developed to determine metformin hydrochloride both in its pharmaceutical dosage forms and human plasma. Separation was conducted using a Zorbax SB-Phenyl (250 × 4.6 mm id) stainless steel column at ambient temperature after pre-column derivatization with 9,10-phenanthraquinone.

Orthogonal projection to latent structures combined with artificial neural networks in non-destructive analysis of ebastine powder.

A new method orthogonal projection to latent structures (O-PLS) combined with artificial neural networks is investigated for non-destructive determination of ebastine powder via near-infrared (NIR) spectroscopy. The modern NIR spectroscopy is efficient, simple and non-destructive technique, which has been used in chemical analysis in diverse fields. Being a preprocessing method, O-PLS provides a way to remove systematic variation from an input data set X not correlated to the response set Y, and does not disturb the correlation between X and Y.

Validation of a micellar liquid chromatographic method for determination of caffeine and non-steroidal anti-inflammatories.

An accurate, simple, sensitive and selective micellar liquid chromatographic method has been developed for the simultaneous determination of caffeine (CAF) and two non-steroidal anti-inflammatory drugs, namely ibuprofen (IBU) and ketoprofen (KET). The chemometric approach was applied to the optimization of separation of the studied drugs. To optimize their separation, the effect of six experimental parameters on retention was investigated by means of multivariate analysis.

Validated spectroflurimetric determination of some H1 receptor antagonist drugs in pharmaceutical preparations through charge transfer complexation.

A validated simple, rapid, and selective spectrofluorimetric method was developed for the determination of some antihistaminic H(1) receptor antagonist drugs namely ebastine (EBS), cetirizine dihydrochloride (CTZ), and fexofenadine hydrochloride (FXD). The method is based on the reaction of the cited drugs with some Π acceptors namely p-chloranilic acid (CLA), tetracyanoethylene (TCNE), and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) to give highly fluorescent derivatives. The fluorescence intensity-concentration plots were rectilinear over the concentration ranges of 0.

First and second derivative synchronous fluorescence and spectrophotometric spectroscopy for the simultaneous determination of fexofenadine hydrochloride in presence of its degradation products. Application to stability studies.

Two rapid, simple, sensitive, selective and economic derivative spectrophotometric (first [D1] and second [D2]) and synchronous spectrofluorimetric (FDSFS and SDSFS) methods have been developed for the analysis of fexofenadine hydrochloride (FXD) in the presence of its different degradation products. Derivative spectrophotometry (D1) was used to measure FXD at 223 nm in the presence of its alkaline or acidic degradation products, and at 211 nm in the presence of its oxidative degradation product. Derivative spectrophotometry (D2) was used to determine FXD at 217 nm in the presence of its alkaline or acidic degradation products, and at 215 nm in the presence of its oxidative degradation product; the UV degradation product was measured at 211 nm.

Validated stability indicating liquid chromatographic determination of ebastine in pharmaceuticals after pre column derivatization: Application to tablets and content uniformity testing.

An accurate, simple, sensitive and selective reversed phase liquid chromatographic method has been developed for the determination of ebastine in its pharmaceutical preparations. The proposed method depends on the complexation ability of the studied drug with Zn2+ ions. Reversed phase chromatography was conducted using an ODS C18 (150 × 4.

Validated stability-indicating spectrofluorimetric methods for the determination of ebastine in pharmaceutical preparations.

Two sensitive, selective, economic, and validated spectrofluorimetric methods were developed for the determination of ebastine (EBS) in pharmaceutical preparations depending on reaction with its tertiary amino group. Method I involves condensation of the drug with mixed anhydrides (citric and acetic anhydrides) producing a product with intense fluorescence, which was measured at 496 nm after excitation at 388 nm.Method (IIA) describes quantitative fluorescence quenching of eosin upon addition of the studied drug where the decrease in the fluorescence intensity was directly proportional to the concentration of ebastine; the fluorescence quenching was measured at 553 nm after excitation at 457 nm.