Subrata Bhadra

Development and Validation of RP-HPLC Method for Quantitative Estimation of Vinpocetine in Pure and Pharmaceutical Dosage Forms

A simple, precise, specific, and accurate reversed phase high performance liquid chromatographic (RP-HPLC) method was developed and validated for determination of vinpocetine in pure and pharmaceutical dosage forms. The different analytical performance parameters such as linearity, accuracy, specificity, precision, and sensitivity (limit of detection and limit of quantitation) were determined according to International Conference on Harmonization ICH Q2 (R1) guidelines. RP-HPLC was conducted on Zorbax C18 (150 mm length × 4.6 mm ID, 5 μm) column. The mobile phase was consisting of buffer (containing 1.54% w/v ammonium acetate solution) and acetonitrile in the ratio (40 : 60, v/v), and the flow rate was maintained at 1.0 mLmin−1. Vinpocetine was monitored using Agilent 1200 series equipped with photo diode array detector (λ = 280 nm). Linearity was observed in concentration range of 160–240 μgmL−1, and correlation coefficient was found excellent (R2 = 0.999). All the system suitability parameters were found within the range. The proposed method is rapid, cost-effective and can be used as a quality-control tool for routine quantitative analysis of vinpocetine in pure and pharmaceutical dosage forms.

A pragmatic approach to the analysis of a combination formulation

The aim of the paper was to formulate a combined oral dosage form of rosuvastatin calcium and amlodipine besylate and to develop and validate an analytical method to be adopted for both routine quality control assay and in vitro dissolution studies of the formulation. The proposed combination formulation has shown compatibility with the chosen excipients, verified through FT-IR study. A novel gradient RP-HPLC method was developed and validated according to the ICH guideline which was found to be suitable for the simultaneous estimation of rosuvastatin calcium and amlodipine besylate from the formulation. The retention time of 2.7 and 6.08 min allows the analysis of large amount of samples with less mobile phase which makes the method economic. The dissolution profiles of both the drugs in different dissolution medium were encouraging which makes the combination formulation of rosuvastatin calcium and amlodipine besylate superior and effective in achieving patient compliance.

Development and Validation of Colorimetric and RP - HPLC Methods for the Determination of Formaldehyde in Cosmetics

Aims: To develop and validate two assay methods for the determination of total and free formaldehyde content in cosmetics by Colorimetric and High Performance Liquid Chromatographic (HPLC) methods, respectively. Study Design: Colorimetric and HPLC methods. Place and Duration of Study: Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Dhaka, Dhaka-1000, Bangladesh; between February 2012 and June 2013. Short Research Article Rahman et al.; ACSj, 5(3): 224-237, 2015; Article no.ACSj.2015.022 225 Methodology: In Colorimetric method the quantitation was performed by a UV/Vis spectrophotometer at 410 nm and by HPLC at 345 nm and the methods were linear over the concentration ranges of 4-12 mg/L (R 2 =0.999) and 2-32 mg/L (R 2 =0.999), respectively. Based on 2, 4-dinitrophenylhydrazine (DNPH) derivatization, free formaldehyde was analyzed using a Phenomenex C18 (250 mm × 4.6 mm i. d., 5 μm particle size) column in a binary separation mode with mobile phase consisting of acetonitrile and distilled water (45:55, v/v) and flow rate of 2.0 mL/min. Results: The overall recovery rate of free formaldehyde was (95.33-98.37)±(0.29-1.6)% (RSD). Seventy five cosmetics of local and foreign brands were investigated. None of those products was labeled to contain formaldehyde. 18 products were labeled with specific formaldehyde donors (17 with DMDM hydantoin and 1 with imidazolidinyl urea). 64% of the products were formaldehyde positive among which 54% exceeded 0.05% limit of formaldehyde content for which EU dictates the mandatory formaldehyde donors labeling. The investigated amounts of the total formaldehyde and free formaldehyde were 190-5502 mg/L and 47-604 mg/L, respectively. Conclusion: The methods were found valid as per in terms of suitability, linearity, accuracy, sensitivity, ruggedness, and robustness. The formaldehyde content found in the cosmetics was highly alarming and must be addressed by the authority in an immediate basis.