Analysis

Two simple, accurate, fast and economical methods have been developed for the quantitative estimation of aceclofenac and indapamide from their respective tablet formulation using Folin-Ciocalteu reagent. Aceclofenac forms a blue colored chromogen with the reagent, which shows absorbance maxima at 642.6 nm and linearity in the concentration range of 80-160 µg/ml of drug.

The present paper describes two simple, accurate, rapid, precise and economical procedures for simultaneous estimation of chlordiazepoxide and trifluoperazine hydrochloride in combined tablet dosage formulations. The first meth¬od is based on the multicomponent mode of analysis of the instrument used; the second method is developed on simultaneous equations.

A simple, fast, precise and accurate liquid chromatographic method was developed for the simultaneous estimation of paracetamol and domperidone in combined dosage forms. This combination is used for antiemetic and pain associated with gastrointestinal disorders.

Two simple, rapid, accurate and economical methods have been developed for the estimation of valdecoxib and tizanidine HCl in the mixture. Valdecoxib has an absorbance maximum at 243 nm and tizanidine HCl has two absorbance maxima at 228 nm and 320 nm in methanol:0.1 M HCl (1:1) mixture.

Simple and reproducible HPTLC method was developed for the separation and quantitation of simvastatin, pravastatin sodium and rosuvastatin calcium, cholesterol lowering agents in pharmaceutical dosage forms. The stationary phase used was precoated silica gel 60F 254 . The mobile phase used was a mixture of chloroform:methanol:toluene (6:2:2, v/v/v).

A simple, precise, fast and selective HPLC method has been developed for the simultaneous estimation of lamivudine, zidovudine and nevirapine from tablets by external standard method.

A simple analytical method for the estimation of tegaserod maleate has been developed to analyze the drug in bulk and in tablet formulation. The method is based on difference spectroscopy and is quite simple, rapid, inexpensive and sensitive. The Beer's law range was followed in the concentration range of 1-30 µg/ml of tegaserod maleate. The molar absorptivity was 1.7920×10 4 l/mole/ cm.

A rapid, simple, accurate and precise UV Spectrophotometric method using simultaneous equation was developed for the simultaneous determination of amlodipine besylate and atorvastatin calcium in a binary mixture. In the proposed method, the signals were measured at 238.2 and 246.6 nm corresponding to the absorbance maxima of amlodipine besylate and atorvastatin calcium in methanol, respectively.

Quantitative analysis of poorly water-soluble drugs involves use of various organic solvents. Major drawbacks of organic solvents include high cost, volatility and toxicity. Safety of analyzer is affected by toxicity of the solvent used.

Piperazine and its salts are reacted with alcoholic p-benzoquinone and buffered at pH 5.4 to give a coloured product with maximum absorption at 516 nm. The piperazine base has a molar absorptivity of 0.96 × 10 4 1/mol/cm, and Beer's law is obeyed in the range of 4-20 µg/ml.