Quantitative analysis of Loperamide hydrochloride in the presence its acid degradation products

Hemijska industrija (Impact Factor: 0.36). 01/2009; 63(1). DOI: 10.2298/HEMIND0901039S
Source: DOAJ


The aim of this work was to develop a new RP-HPLC method for the determination of loperamide hydrochloride in the presence of its acid degradation products. Separation of loperamide from degradation products was performed using ZORBAX Eclipse XDB C-18, column with a mobile phase consisting of 0.1% sodium-octansulphonate, 0.05% triethylamine, 0.1% ammonium hydroxide in water:acetonitrile (45:55 v/v). The mobile phase was adjusted to pH 3.2 with phosphoric acid. The method showed high sensitivity with good linearity over the concentration range of 10 to 100 μg cm-3. The method was successfully applied to the analysis of a pharmaceutical formulation (Loperamide, Zdravlje-Actavis, Serbia) containing loperamide hydrochloride with excellent recovery. The loperamide hydrochloride degradation during acid hydrolysis and kinetics investigation was carried out in hydrochloric acid solutions of 0.1, 1.0 and 1.5 mol dm-3, at different temperatures (25 and 40°C), by monitoring the parent compound itself. The first order reaction of loperamide degradation in acid solution was determined. The activation energy was estimated from the Arrhenius plot and it was found to be 38.81 kJ mol-1 at 40°C. The developed procedure was successfully applied for the rapid determination of loperamide hydrochloride in pharmaceutical formulation (Loperamide, Zdravlje-Actavis, Serbia) and in the presence of its acid degradation products.

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    • "In humans, following oral administration of loperamide solid formulations, about 50% of the administered loperamide is absorbed in the gastrointestinal tract, absorbance occurring within 1 h in high bounding percent to plasma proteins (95%) [8], at maximum concentration time of 6 h and half-life around 11 h [9], but only a little intact drug (1%) reaches systemic circulation, due to its extensive first pass metabolism [6] [7]. Loperamide determination in human body makes challenging work in bioavailability and bioequivalence research field, due to its low availability in plasma and low doses [6] [7], in pharmaceutical industries and in vitro studies, loperamide has been determined by HPLC easily [10] [11] [12] [13] [14], and more sensitive methods were required for in vivo determinations, as in rats by HPLC–UV [15] and HPLC–ECD [16]. In human body there were many determinant studies of loperamide by using LC-tandem MS [17] [18] [19] [20], but more sensitive bioanalytical methods with easier 1570-0232/© 2014 Elsevier B.V. All rights reserved. "
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    ABSTRACT: A simple and sensitive liquid chromatography-tandem mass spectrometric method for quantification of loperamide in human plasma and saliva was developed and validated, and then successfully applied in pharmacokinetic clinical study to investigate and correlate bioavailability of Imodium (R) 2 mg quartet tablet dose in both human plasma and saliva. Loperamide with labeled internal standard was extracted from its biological matrix by methanol as protein direct precipitant in single extraction step. Adequate chromatographic separation for analytes from plasma and saliva matrices was achieved using ACE C18 (50mm x 2.1 mm, 5 mu m) column, eluted by water/methanol/formic acid (30:70:0.1%, v/v), delivered isocratically at constant flow rate of 0.75 ml/min. The method validation intends to investigate specificity, sensitivity, linearity, precision, accuracy, recovery, matrix effect and stability according to European guideline, and partial validation was applied on saliva, specificity, matrix effect, recovery, sensitivity, within and between day precision and accuracy. The calibration curve was linear through the range of 20-3000 pg/ml in both plasma and saliva using a 50 mu l sample volume. The partial validation sections outcome in saliva was so close to those in plasma. The within- and between-day precisions were all below 8.7% for plasma and below 11.4% for saliva. Accuracies ranged from 94 to 105% for both matrices. In this study, 26 healthy volunteers participated in the clinical study, and 6 of gave their saliva samples in addition to plasma at the same time schedule. The pharmacokinetic parameters of C-max, AUC(0-t) and AUC(0-infinity), T-max and T-1/2 in both plasma and saliva were calculated and correlated.
    Journal of Chromatography B 12/2014; 972. DOI:10.1016/j.jchromb.2014.09.037 · 2.73 Impact Factor