Optimization and Validation of Spectrophotometric Methods for Determination of Finasteride in Dosage and Biological Forms.

Optimization and validation of spectrophotometric methods for determination of finasteride in dosage and biological forms.

Pharm Methods. 2012 Jan; 3(1): 48-55
Amin AS, Kassem MA

Three simple, accurate and sensitive spectrophotometric methods for the determination of finasteride in pure, dosage and biological forms, and in the presence of its oxidative degradates were developed.These methods are indirect, involve the addition of excess oxidant potassium permanganate for method A; cerric sulfate [Ce(SO4)2] for methods B; and N-bromosuccinimide (NBS) for method C of known concentration in acid medium to finasteride, and the determination of the unreacted oxidant by measurement of the decrease in absorbance of methylene blue for method A, chromotrope 2R for method B, and amaranth for method C at a suitable maximum wavelength, ?max: 663, 528, and 520 nm, for the three methods, respectively. The reaction conditions for each method were optimized.Regression analysis of the Beer plots showed good correlation in the concentration ranges of 0.12-3.84 ?g mL-1 for method A, and 0.12-3.28 ?g mL-1 for method B and 0.14 – 3.56 ?g mL-1 for method C. The apparent molar absorptivity, Sandell sensitivity, detection and quantification limits were evaluated. The stoichiometric ratio between the finasteride and the oxidant was estimated. The validity of the proposed methods was tested by analyzing dosage forms and biological samples containing finasteride with relative standard deviation ? 0.95.The proposed methods could successfully determine the studied drug with varying excess of its oxidative degradation products, with recovery between 99.0 and 101.4, 99.2 and 101.6, and 99.6 and 101.0% for methods A, B, and C, respectively. HubMed – drug


A validated ultra high-pressure liquid chromatography method for separation of candesartan cilexetil impurities and its degradents in drug product.

Pharm Methods. 2012 Jan; 3(1): 31-9
Kumar ND, Babu KS, Gosada U, Sharma N

A selective, specific, and sensitive “Ultra High-Pressure Liquid Chromatography” (UPLC) method was developed for determination of candesartan cilexetil impurities as well asits degradent in tablet formulation.The chromatographic separation was performed on Waters Acquity UPLC system and BEH Shield RP18 column using gradient elution of mobile phase A and B. 0.01 M phosphate buffer adjusted pH 3.0 with Orthophosphoric acid was used as mobile phase A and 95% acetonitrile with 5% Milli Q Water was used as mobile phase B. Ultraviolet (UV) detection was performed at 254 nm and 210 nm, where (CDS-6), (CDS-5), (CDS-7), (Ethyl Candesartan), (Desethyl CCX), (N-Ethyl), (CCX-1), (1 N Ethyl Oxo CCX), (2 N Ethyl Oxo CCX), (2 N Ethyl) and any unknown impurity were monitored at 254 nm wavelength, and two process-related impurities, trityl alcohol and MTE impurity, were estimated at 210 nm. Candesartan cilexetil andimpurities were chromatographed with a total run time of 20 min.Calibration showed that the response of impurity was a linear function of concentration over the range limit of quantification to 2 ?g/mL (r2?0.999) and the method was validated over this range for precision, intermediate precision, accuracy, linearity, and specificity. For the precision study, percentage relative standard deviation of each impurity was <15% (n=6).The method was found to be precise, accurate, linear, and specific. The proposed method was successfully employed for estimation of candesartan cilexetil impurities in pharmaceutical preparations. HubMed – drug


Ion-pair spectrophotometric estimation of gemifloxacin.

Pharm Methods. 2012 Jan; 3(1): 26-30
Sahu S, Patro SK, Narayan UL, Garnaik B

The main objective was to develop and validate a simple, accurate, precise, and sensitive ion-pair spectrophotometric extraction method for the assay of gemifloxacin mesylate (GFX) in pure, tablets and spiked human urine.The method is based upon the reaction of gemifloxacin with methyl orange, forming a yellow-colored complex in acidic medium, which is extracted in chloroform and analyzed. The extracted complexes showed absorbance maxima (?max) found to be at 427 nm.Beer’s law was obeyed for a wide concentration range, i.e., 10-80 ?g/ mL as the extracted species seemed well defined and stable. The surface or an interphase adsorption phenomenon was not a problem. Optimization of the reaction was carried out with factors such as buffer strength, stability of complex, and molar ratio of drug: Dye and extraction time. The proposed method was validated as per the ICH guidelines. The recovery studies confirmed the accuracy and precision of the method.The above-mentioned method was a rapid tool for routine analysis of GFX in the bulk and pharmaceutical dosage forms. HubMed – drug


Quantitative estimation of diacerein in bulk and in capsule formulation using hydrotropic solubilizing agents by UV-spectrophotometry and the first order derivative using the area under curve method.

Pharm Methods. 2012 Jan; 3(1): 4-8
Pandey R, Patil PO, Patil MU, Deshmukh PK, Bari SB

This study was designed to develop and validate two simple, rapid, and economical UV-spectrophotometric and the first-order derivative methods using the area under curve method for estimation of diacerein in bulk and in capsule formulation.In this study, hydrotrophic solution of 8 M urea and 0.5 M potassium citrate were employed as the solubilizing agent to solubilize a poorly water-soluble drug, diacerein. In the UV-spectrophotometry method, two wavelengths 252.0 nm and 266.2 nm and in the first-order derivative spectrophotometric methods two wavelengths 259.4 nm and 274.2 nm in 8 M urea and two wavelengths 247.8 nm and 267.4 nm in the UV-spectrophotometry method and in the first-order derivative spectrophotometric methods two wavelengths 259.2 nm and 274.2 nm in 0.5 M potassium citrate were selected for determination of areas.Hydrotrophic agents used did not interfere in spectrophotometric analysis of diacerein. Diacerein followed linearity in the concentration range of 2-12 ?g/mL with a coefficient correlation of 0.999 for both methods.The amount of drugs estimated by both proposed methods are in good accord with label claim. The % RSD value in recovery, precision, and ruggedness studies are found to be less than 2 indicate that the method is accurate, precise, and rugged. HubMed – drug



The Florida Recovery Center at the University Of Florida – Dr. Teitelbaum talks about the Florida Recovery Center at the University of Florida.