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Biomedical subjects

V Das Gupta

Publications and source records attributed to V Das Gupta.

At least 37 records · Page 2Linked to original sources
PubMed1988

Chemical stabilities of famotidine and ranitidine hydrochloride in intravenous admixtures.

The chemical stabilities of famotidine and ranitidine hydrochloride solutions in 5% dextrose and 0.9% sodium chloride injections have been studied using high-performance liquid chromatographic methods (HPLC). Both the drugs were stable for at least 15 days (loss in potency of less than 10%) at 25 degrees C and 63 days at 5 degrees C. Both drugs were comparatively less stable in 5% dextrose injection than in 0.9% sodium chloride injection. The loss in the potency of phenol, which is added as a preservative to ranitidine hydrochloride injection, was significant in both the vehicles. However, the addition of preservative in a single dose vial is not considered necessary.

Chromatography, High Pressure Liquid↗
PubMed1987

Chemical stability of thiopental sodium injection in disposable plastic syringes.

The chemical stability of thiopental sodium injection (2.5%) when stored at 25 degrees and 5 degrees in disposable plastic syringes of two manufacturers (Monoject and Becton Dickenson and Co.) has been studied using the USP-NF method. The injection appeared to be stable for five days at 25 degrees and 45 days at 5 degrees with a loss in potency of less than 7%. The thiopental sodium did not adsorb on the syringes. The pH values and the physical appearance did not change. An additional peak was obtained in the chromatogram from both the freshly prepared and the assay solution probably due to an impurity in the powder.

Disposable Equipment↗
PubMed1986

Stability of cefuroxime sodium in some aqueous buffered solutions and intravenous admixtures.

Cefuroxime sodium (Zinacef) is a new semisynthetic, broad spectrum cephalosporin antibiotic for parenteral administration which is stable to most of the beta-lactamases. The stability of cefuroxime sodium in aqueous solutions, with or without phosphate buffer, and in 5% dextrose and 0.9% sodium chloride injections was studied using a stability-indicating high-pressure liquid chromatographic method developed in our laboratory. The optimum pH range of stability was determined to be approximately 4.5-7.3. Both buffered and unbuffered solutions followed first-order decomposition. In 5% dextrose and 0.9% sodium chloride injections, cefuroxime was stable for 1 day (more than 90% potent) at 25 degrees C and for at least 30 days at 5 degrees C. At -10 degrees C, there was negligible decomposition after 30 days. The pH values of the solutions stored at 5 degrees C and -10 degrees C remained in the maximum stability range and the solutions were clear even after 30 days of storage. Thawing the frozen solutions in a microwave oven adversely affected the stability.

Buffers↗
PubMed1986

Stability of hydralazine hydrochloride in aqueous vehicles.

The stability of hydralazine hydrochloride in aqueous vehicles which contain either dextrose, fructose, lactose, maltose, mannitol, sorbitol or sucrose has been studied using a stability-indicating high-performance liquid chromatographic method. Dextrose, fructose, lactose and maltose had adverse effects on the stability of hydralazine. In mannitol (better than sorbitol) and sorbitol, hydralazine was stable for about 21 days (loss in potency of less than 10%) and sucrose had an adverse effect only after its hydrolysis to fructose and dextrose. The optimum pH range of stability in dextrose was approximately between 3.2 and 4.4. The first-order rate of decomposition increased with an increase in the concentration of dextrose but not with an increase in the concentration of hydralazine. In the absence of other excipients the phosphate and citrate buffers did not adversely affect the stability of hydralazine hydrochloride.

Chromatography, High Pressure Liquid↗
PubMed1986

Chemical stabilities of lignocaine hydrochloride and phenylephrine hydrochloride in aqueous solution.

The chemical stabilities of lignocaine hydrochloride (lidocaine hydrochloride) and phenylephrine hydrochloride in a combination aqueous solution have been determined using stability-indicating high-performance liquid chromatographic methods. The drugs did not interact and were stable for at least 66 days at room temperature. The pH value changed from 6.0 to 5.8 after 66 days but was still within the optimum pH range for the stabilities of lignocaine and phenylephrine.

Chromatography, High Pressure Liquid↗
PubMed1986

Stability of vancomycin hydrochloride in 5% dextrose and 0.9% sodium chloride injections.

The stability of vancomycin hydrochloride mixed with 5% dextrose and 0.9% sodium chloride injections was studied. Vancomycin hydrochloride powder was mixed with each of the two diluents in final concentrations of 5 mg/mL. Duplicate samples of each admixture were divided into four parts and stored at 24 degrees C in glass and in plastic i.v. bags for 17 days and at 5 degrees C and -10 degrees C in glass for 63 days. To additional samples, hydrochloric acid or phosphate buffer was added; these were stored at 24 degrees C for 17 days. At various storage times, clarity and pH of the samples were recorded and vancomycin concentrations were measured in triplicate by high-performance liquid chromatography. Except for the buffered samples, all solutions remained clear and pH was unchanged. Vancomycin concentrations decreased less than 6% during 17 days at room temperature. In the refrigerated and frozen samples, vancomycin concentrations decreased less than 1% throughout the study. Vancomycin hydrochloride is stable in admixtures with 5% dextrose injection and 0.9% sodium chloride injection for 17 days at 24 degrees C and for 63 days at 5 degrees C and -10 degrees C.

Chromatography, High Pressure Liquid↗
PubMed1985

Stability of metronidazole and ten antibiotics when mixed with magnesium sulphate solutions.

The chemical stabilities of metronidazole (in water) and ten antibiotics (ampicillin, carbenicillin, cefamandole, cefazolin, cefoxitin, moxalactam, nafcillin, penicillin G, piperacillin, and ticarcillin) in 5% dextrose injection (except ampicillin which was in 0.9% sodium chloride) with magnesium sulphate were studied at 25 degrees C. The clarity of the solutions did not change in 20 h. The pH values of metronidazole, nafcillin and penicillin G solutions containing magnesium sulphate were lower (at 0 and 20 h) by up to 1.2 units as compared with solutions without magnesium sulphate. The decomposition of nafcillin and penicillin G solutions was hastened significantly by magnesium sulphate due to effect on the pH values of the solutions.

Anti-Bacterial Agents↗
PubMed1985

Chemical stabilities of cefamandole nafate and metronidazole when mixed together for intravenous infusion.

The chemical stabilities of cefamandole nafate and metronidazole, when mixed together for intravenous infusion, have been studied using a stability-indicating, high-performance liquid chromatographic method of assay. Cefamandole nafate was stable for 5 days at 25 degrees C and at least 14 days at 5 degrees C. The addition of metronidazole did not affect the stability of cefamandole nafate. In a 2% solution of cefamandole in metronidazole injection (0.5%), metronidazole lost about 9.1% of potency in less than 2 h at 25 degrees C and in less than 6 h at 5 degrees C. The per cent loss was directly related to the initial concentration of cefamandole nafate. Change in the concentration of metronidazole did not affect the per cent of metronidazole lost.

Cefamandole↗
PubMed1985

pH-dependent effect of magnesium sulfate on the stability of penicillin G potassium solution.

The effect of magnesium sulfate on the stability of penicillin G potassium solutions (0.5 mg/mL) was investigated using a stability-indicating high-performance liquid chromatography method. The penicillin G potassium powder buffered with and without citrate was used. Twelve aqueous duplicate penicillin solutions with various concentrations of magnesium sulfate and with or without buffers were prepared and stored at room temperature. Data on clarity, pH values, and HPLC assay results were determined at intervals during the 10-day storage period. The results indicated that the presence of high concentrations of magnesium sulfate in unbuffered penicillin solutions can cause large pH changes and the degradation of penicillin. However, the effect of magnesium sulfate on the stability of penicillin G potassium was negligible in the buffered solutions. Solutions with a constant pH value of 5.6 prepared using 0.1 M acetate buffer with and without magnesium sulfate showed similar apparent first-order degradation after the 10-day storage period at 24 degrees C. During decomposition, the pH values of the unbuffered solutions decreased for three days and then started increasing in most solutions. The degradation of penicillin G potassium by magnesium sulfate in aqueous solutions resulted from decreases in pH values of the solutions.

Chemistry, Pharmaceutical↗
PubMed1984

Stability of cefotaxime sodium as determined by high-performance liquid chromatography.

The stability of cefotaxime sodium in water (with either hydrochloric acid, phosphate buffers, or other ingredients) dextrose, and sodium chloride has been studied using a stability-indicating high-performance liquid chromatographic method with a relative standard deviation of 1.9% based on six injections. The optimum pH range of stability was determined to be approximately 4.3-6.2. In this pH range, the decomposition process was catalyzed only by the solvent. At pH less than or equal to 3.4, the hydrogen ion also catalyzed the reaction while at pH greater than 6.2, the hydroxyl ion hastened the process of decomposition. The solutions in 5% dextrose and 0.9% NaCl injections were stable for at least 1, 22, and 112 d at 24 degrees C, 4 degrees C, and -10 degrees C, respectively. For both solutions, the loss in potency was less than 5% at -10 degrees C in 224 d, less than 9% at 4 degrees C in 42 d, and less than 3.1% at 24 degrees C in 1 d.

Cefotaxime↗
PubMed1984

Quantitation of phenobarbital and phenobarbital sodium in pharmaceutical dosage forms.

A reverse-phase high-performance liquid chromatographic method for the quantitation of phenobarbital and phenobarbital sodium in pharmaceutical dosage forms (elixir, injection, and tablets) was developed. The method is precise and accurate with percent relative standard deviations of 0.9 (without an internal standard) and 0.7 (with an internal standard) based on six injections. The method is stability indicating and is more sensitive than the revised USP-NF method. The products of decomposition showed two new peaks in the chromatogram.

Chromatography, High Pressure Liquid↗
PubMed1984

Quantitation of metronidazole in pharmaceutical dosage forms using high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) method for the quantitation of metronidazole in pharmaceutical dosage forms has been developed. The method is accurate and precise with an RSD of 0.68%, based on six readings. The excipients present in various dosage forms did not interfere with the assay procedure. A solution of metronidazole decomposed using heat showed 0% potency.

Chromatography, High Pressure Liquid↗
PubMed1984

Quantitation of acetaminophen, chlorpheniramine maleate, dextromethorphan hydrobromide, and phenylpropanolamine hydrochloride in combination using high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) method has been developed for the quantitation of acetaminophen, chlorpheniramine maleate, dextromethorphan hydrobromide, and phenylpropanolamine hydrochloride in combination in pharmaceutical dosage forms using a single column and three different mobile phases. The method developed is sensitive for the content uniformity test for tablets. No preliminary extraction procedure is required for liquid preparation and a very simple extraction procedure is required for tablets. The method is accurate and precise with RSD (based on five injections) of 1.2, 2.4, 1.9, and 1.6% for acetaminophen, chlorpheniramine, dextromethorphan, and phenylpropanolamine, respectively.

Acetaminophen↗
PubMed1984

Effect of ethanol, glycerol, and propylene glycol on the stability of phenobarbital sodium.

The effects of ethanol, glycerol, propylene glycol, phosphate buffer, and ionic strength on the stability of phenobarbital sodium have been studied. Ethanol had the maximum stabilization effect followed by propylene glycol and glycerol when compared with the stability in water. The estimated half-lives at 50 degrees C (pH approximately 8) were 78, 95, 109, and 127 d in water and 20% aqueous solutions of glycerol, propylene glycol, and ethanol, respectively. The effects of phosphate buffer and ionic strength were negligible.

Drug Stability↗