PubMed Health⌕ Search

Biomedical subjects

V Das Gupta

Publications and source records attributed to V Das Gupta.

At least 73 records · Page 4Linked to original sources
PubMed1978

Stability-indicating methods for quantitative determination of spironolactone using high-pressure liquid chromatography and blue tetrazolium reaction.

Stability-indicating methods for the quantitative determination of spironolactone were developed. The methods are based on high-pressure liquid chromatography and a reaction with blue tetrazolium. Both methods are accurate, precise, and sensitive and gave excellent results with commercial tablets, including those containing hydrochlorothiazide in addition to spironolactone, The blue tetrazolium method cannot be used in the presence of high concentrations of either polyethylene glycols or water. Spironolactone decomposition in water or polyethylene glycol appears to follow pseudo-first-order kinetics. The decomposition constant at 65 degrees was 0.0253/day in water versus 0.115/day in polyethylene glycol ointment base USP.

Chromatography, High Pressure Liquid↗
PubMed1978

Stability of pediatric liquid dosage forms of ethacrynic acid, indomethacin, methyldopate hydrochloride, prednisone and spironolactone.

The stability of liquid dosage forms of ethacrynic acid (1 mg/ml), indomethacin (2 mg/ml), methyldopate hydrochloride (25 mg/ml), prednisone (0.5 mg/ml) and spironolactone (2 mg/ml), which often are compounded extemporaneously, was studied. One or two liquid dosage forms of each of the five drugs was prepared with the pure drug or the powder from a commercial dosage form using aqueous sorbitol or simple syrup alone or with a 10% (v/v) solution of alcohol in water. The dosage forms were stored at 24 C in amber-colored bottles for 21-224 days and assayed by various methods. All solutions studied were stable for at least 84 days. A solution was considered stable if it retained 90% of its drug concentration. Except for the prednisone solution, all solutions were stable for at least 164 days; however, the solution of methyldopate hydrochloride prepared from the pure drug became discolored after 98 days. The liquid dosage forms studied have limited stability but can be used by the pharmacist when extemporaneous oral solutions of these drugs are needed.

Child↗
PubMed1977

Quantitative determination of four antihistamines in combination by high-pressure liquid chromatography.

A procedure used to assay four antihistamines--brompheniramine maleate, chlorpheniramine maleate, pheniramine maleate and pyrilamine maleate in combination--is discussed. The method requires a high-pressure liquid chromatograph and an intermediate polarity column. The method is accurate and appears to be stability-indicating. The four antihistamines can be separated and assayed accurately. There is no interference from the two commonly used decongestants, phenylephrine hydrochloride and phenylpropanolamine hydrochloride, from the expectorant potassium guaiacolsulfonate, from the preservative propyl paraben or from two other antihistamines, diphenhydramine hydrochloride and bromdiphenhydramine hydrochloride. Guaifenesin, methylparaben and sodium benzoate interfere only with pheniramine maleate. Methapyrilene hydrochloride interferes only with pyrilamine maleate.

Chromatography, High Pressure Liquid↗
PubMed1977

Potassium hydroxide solution 10% for the fast hydrolysis of esters for analysis.

The applicability of a five-minute hydrolysis method with 10% potassium hydroxide in an alcohol-water (80-20) mixture was investigated for the quantitative determination of certain esters (aspirin, benzocaine, benzyl benzoate, methyl paraben, phenyl salicylate, procaine hydrochloride, propyl paraben, salicylanilide and 0-salicylsalicylic acid) and salicylamide. The results indicate that the method is satisfactory for all but methyl paraben and propyl paraben.

Benzocaine↗
PubMed1976

Quantitative determinations of phenol and resorcinol in pharmaceutical dosage forms by high-pressure liquid chromatography.

The quantitative determinations of phenol in phenolated calamine lotion USP and of phenol and resorcinol in phenol-resorcinol-boric acid solution by high-pressure liquid chromatography are reported. The procedures are simple, rapid (no special preliminary treatment is required), and accurate. There is no interference from other ingredients of the lotion (bentonite magma, calamine, and zinc oxide) or solution (acetone and boric acid).

Chromatography, High Pressure Liquid↗
PubMed1976

Quantitative determination of piperazine citrate in piperazine citrate syrup USP.

An assay for piperazine citrate in Piperazine Citrate Syrup USP is described. The assay method is based on the formation of a complex of piperazine with an acid dye, bromothymol blue. The complex can be extracted with chloroform and measured spectrophotometrically. The method is accurate and requires only 15 minutes for analysis, compared to four to five hours by the USP method.

Hydrogen-Ion Concentration↗
PubMed1975

Quantitative determination of phenol in phenolated calamine lotion USP.

A method for the quantitative analysis of phenol in phenolated calamine lotion USP is described. The method is based on spectrophotometrically measuring the color produced by reacting phenol with either ferric chloride or ferric nitrate. Beer's law is followed. The effect of ferric-ion concentration on the sensitivity of the assay method is reported.

Colorimetry↗
PubMed1975

Colorimetric determinations of chlorpheniramine maleate, ephedrine hydrochloride, and guaiacolsulfonate potassium in a cough syrup.

Colorimetric methods for the quantitative determinations of chlorpheniramine maleate, ephedrine hydrochloride, and guaiacolsulfonate potassium in a cough syrup containing color (amaranth) are reported. Chlorpheniramine maleate can be assayed using the cyanogen bromide method as reported in the literature. Ephedrine hydrochloride can be assayed using a dye method in which interference from chlorpheniramine maleate is taken into consideration. Guaiacolsulfonate potassium can be assayed by coupling it with 4-aminoantipyrine (the method is similar to the one for phenylephrine hydrochloride). All of the methods are simple, accurate, and precise. The application of the guaiacolsulfonate potassium assay method to commercial dosage forms is reported.

Antitussive Agents↗