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Biomedical subjects

V D Gupta

Publications and source records attributed to V D Gupta.

At least 37 records · Page 2Linked to original sources

Modified NF method for quantitative determination of pentaerythritol tetranitrate.

A modified NF method for the quantitative determination of pentaerythritol tetranitrate is reported. A solution of powder is made directly from the dosage form in glacial acetic acid and is then reacted with phenoldisulfonic acid TS. The proposed method saves approximately 75% of the time required with the NF method. The results on six differnet commercial dosage forms with four different colors and three other active ingredients are reported.

Methods↗

Quantitative determination of benzoic acid and salicyclic acid in ointments by high-pressure liquid chromatography.

Benzoic acid and salicyclic acid in ointments were analyzed quantitatively by reversed-phase high-pressure liquid chromatography. Both benzoic and salicyclic acids can be assayed in combinations directily without interference from each other or the ointment bases. The method is accurate, simple, and rapid. Excellent results were obtained with three commercial bases.

Benzoates↗

Quantitative determinations of codeine phosphate, guaifenesin, pheniramine maleate, phenylpropanolamine hydrochloride, and pyrilamine maleate in an expectorant by high-pressure liquid chromatography.

The quantitative determinations of codeine phosphate, guaifenesin, pheniramine maleate, phenylpropanolamine hydrochloride, and pyrilamine maleate in a liquid dosage form are described. All active and inactive ingredients (sodium benzoate and FD&C Yellow No. 5 dye) can be separated with high-pressure liquid chromatography except the two antihistamines, pheniramine maleate and pyrilamine maleate. Pheniramine maleate is determined colorimetrically, and pyrilamine maleate is determined either by difference or spectrophotometrically. The methods are simple short, accurate, and precise. The standard deviations are reported.

Chromatography, High Pressure Liquid↗

Quantitative determinations of antipyrine and benzocaine in ear drops by high-pressure liquid chromatography.

Antipyrine and benzocaine were determined quantitatively in ear drops by high-pressure liquid chromatography on an octadecyltrichlorosilane permanently bonded to a Si-C column, using 0.02 M KH2PO4 in methanol-water as the mobile phase. Both compounds can be assayed in combination directly without interference from each other or from oxyquinoline sulfate (the preservative). The method is accurate, precise (estimated universe standard deviations of 0.68% for antipyrine and 1.18% for benzocaine), simple, and short (requires 30 min versus 2-3 hr by the NF method). The method was tried on a commercial product with excellent results and can be used in the presence of decomposition products.

Antipyrine↗

Quantitative determination of resorcinol in presence of phenol.

A simple and accurate method for the quantitative determination of resorcinol in the presence of phenol is reported. The method is based on the formation of indophenol by reacting resorcinol with 2, 6-dibromoquinone-4-chlorimide. The concentration of indophenol can be measured spectrophotometrically. This method is recommended for the determination of resorcinol in resorcinol-phenol-boric acid solution and carbol-fuchsin solution. The decomposition products of resorcinol and phenol, e.g., colored quinones, do not interfere with the assay procedure.

Colorimetry↗

Quantitative determination of benzyl benzoate in benzyl benzoate lotion NF.

The development of a simple, shorter and more accurate method than the NF method for the determination of benzyl benzoate in Benzyl Benzoate Lotion NF is discussed. Hydrolyzed benzyl benzoate was measured spectrophotometrically. Interference from other ingredients of the lotion, oleic acid and triethanolamine was almost negligible. The proposed method was completed in approximately 15 minutes, as opposed to the two hours required by the NF procedure.

Benzoates↗

Comparison of stability-indicating assay methods: ultraviolet, high pressure liquid chromatography and acid dye.

Three techniques--ultraviolet, high pressure liquid chromatography (HPLC) and acid dye--were compared as stability-indicating assay methods. Investigations on six drugs (codeine phosphate, ephedrine hydrochloride, morphine sulfate, procaine hydrochloride, pyrilamine maleate and thiamine hydrochloride) indicate that HPLC is the most reliable method.

Chromatography, High Pressure Liquid↗

Quantitative determination of alkaloids in belladonna tincture USP.

A simplified method for the quantitative analysis of hyoscyamine hydrobromide or atropine in Belladonna Tincture USP is described. The procedure is based on the formation of an alkaloid-dye complex which can be extracted with an organic solvent and measured spectrophotometrically. The results obtained by this method compare favorably with those obtained by the USP method.

Atropa belladonna↗

Quantitative determination of phenol in ointments.

A quantitative method for the assay of phenol in ointments is described. The procedure involves the formation of a blue indophenol by reacting phenol with 2,6-dibromoquinone-4-chloroimide which can be measured spectrophotometrically. The method is accurate, and interference from other active ingredients (hydrocortisone and menthol) does not occur.

Hydrocortisone↗