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Biomedical subjects

J Parasrampuria

Publications and source records attributed to J Parasrampuria.

13 recordsLinked to original sources
PubMed1998

Guar gum-based sustained release diltiazem.

PURPOSE: This study was performed to examine the use of guar gum to sustain the release of diltiazem under in vitro and in vivo conditions. METHODS: Guar gum tablet formulations were prepared and evaluated under a variety of in vitro dissolution conditions. The formulations, along with Dilacor XR, were administered to a group eight fasted, healthy volunteers in a four period crossover study. RESULTS: Varying the lot of guar gum as well as using guar from different suppliers had little effect on diltiazem dissolution. Also, dissolution of diltiazem from guar gum tablets was essentially independent of stir speed under normal conditions (USP Apparatus II) The stability of guar-based formulations under stressed conditions (40 degrees C/75% relative humidity for 3 months) was also established. All four formulations gave similar plasma concentrations over time in the healthy volunteers pharmacokinetic study. CONCLUSIONS: Guar gum-based matrix tablets represent a simple and economical alternative to existing diltiazem sustained release dosage forms.

Antihypertensive Agents↗
PubMed1998

Moist-heat sterilization and the chemical stability of heat-labile parenteral solutions.

The impact of moist-heat sterilization (autoclaving) on the chemical stability of parenteral solutions was examined using two heat-labile products, clindamycin phosphate and succinylcholine chloride injections, as examples. A nonisothermal kinetic model was used to predict the extent of product degradation during autoclaving. The predicted results were found to be in close agreement with the experimental data. For the same peak temperature, a greater loss of product was shown by using a cycle with a higher F0. On the other hand, a higher peak-temperature cycle resulted in less product degradation for the same F0 value. The benefit of a high-temperature cycle was further illustrated by the fact that less chemical degradation for both products was produced by a 122 degrees C cycle with an F0 of 11 as compared to that which occurred during a 116.5 degrees C cycle with an F0 of 8. Although clindamycin phosphate was found to be highly unstable during a conventional autoclaving process, predicted data indicate that a UHT (Ultra-High Temperature) process may be used to sterilize this product with acceptable degradation.

Clindamycin↗
PubMed1992

Stability and sorption of calcitriol in plastic tuberculin syringes.

The stability of commercially formulated calcitriol 1 and 2 micrograms/mL and calcitriol formulation subsequently diluted to 0.5 microgram/mL in 0.9% sodium chloride injection, 5% dextrose injection, or water for injection was evaluated after eight hours' storage in polypropylene syringes. The apparent affinities of calcitriol for polypropylene and polyvinyl chloride were also examined. Three calcitriol 0.5 microgram/mL solutions (diluted in 0.9% sodium chloride injection, 5% dextrose injection, or water for injection) and aqueous calcitriol formulations, 1 and 2 micrograms/mL, were placed in 1-mL polypropylene tuberculin syringes and assayed by high-performance liquid chromatography initially and after two, four, and eight hours' storage under room light at ambient temperature. Samples of calcitriol 2 micrograms/mL were also exposed to polypropylene or polyvinyl chloride at room temperature for 20 days. The remaining calcitriol concentrations were determined and apparent calcitriol polymer/water partition coefficients were calculated. Calcitriol concentrations did not change substantially during the eight-hour stability study. The mean apparent polymer/water partition coefficient for polyvinyl chloride was 66 times that for polypropylene, indicating that calcitriol has a definite affinity for polyvinyl chloride but no similar affinity for polypropylene. Aqueous calcitriol solution 1 or 2 micrograms/mL or 0.5 microgram/mL in 0.9% sodium chloride injection, 5% dextrose injection, or water for injection, when stored in polypropylene syringes exposed to ambient temperature and room light, appears to be stable for eight hours. Calcitriol appears to have greater affinity for polyvinyl chloride than for polypropylene.

Adsorption↗
PubMed1992

Stability of ganciclovir sodium in 5% dextrose injection and in 0.9% sodium chloride injection over 35 days.

The stability of ganciclovir 1 and 5 mg/mL in 5% dextrose injection and in 0.9% sodium chloride injection was studied at 25 degrees C and 5 degrees C over 35 days. Ganciclovir (as the sodium salt) was added to 120 polyvinyl chloride bags containing either 5% dextrose injection or 0.9% sodium chloride injection to attain ganciclovir concentrations of 1 and 5 mg/mL. Thirty bags were prepared for each combination of drug concentration and i.v. solution. Half of the bags in each group were stored at 25 degrees C; the other half were stored at 5 degrees C. Samples withdrawn from all 120 bags immediately after preparation were frozen for later determination of initial concentration. At 7, 14, 21, 28, and 35 days after preparation, approximately 5-mL samples representing each test condition were withdrawn for analysis. The samples were visually examined, tested for pH, and assayed by high-performance liquid chromatography. There was no significant loss of ganciclovir under any of the study conditions over 35 days. All solutions were clear throughout the study period. The pH decreased slightly in both diluents at both ganciclovir concentrations but did not deviate from the manufacturer's range (9-11). Admixtures containing ganciclovir 1 and 5 mg/mL (as the sodium salt) in 5% dextrose injection and 0.9% sodium chloride injection were stable in polyvinyl chloride bags stored at 25 degrees C and 5 degrees C for 35 days.

Chromatography, High Pressure Liquid↗
PubMed1991

Percutaneous delivery of proteins and peptides using iontophoretic techniques.

There has been much interest recently in the delivery of proteins and peptides following the research and development of biotechnology: derived drugs and other bioactive substances. This article summarizes the use of iontophoresis to deliver proteins and peptides across the skin. This technique offers considerable promise for delivering drugs in therapeutic amounts by bypassing the gastrointestinal tract (GIT) and liver metabolism. This article discusses the theory underlying iontophoretic drug delivery and the devices available. The future development of these systems would require the use of specialized approaches to enhance delivery of larger molecules but overall there is considerable optimism.

Administration, Cutaneous↗
PubMed1990

Development of oral liquid dosage forms of acetazolamide.

Two oral liquid dosage forms of acetazolamide have been developed. Using the solubility profiles, polyethylene glycol 400 (7%, v/v) was used as the solubilizing agent and propylene glycol (53%, v/v) as the cosolvent to keep acetazolamide in solution. Because of the bitter taste of acetazolamide, sweetening agents (simple syrup, sorbitol solution, and artificial sweeteners) and flavors (raspberry, sweet, and menthol) were added to the final formulations. A buffer (either phosphate or citrate) solution was used to maintain a pH value of 4 (pH of maximum stability as reported earlier) to minimize hydrolysis. The final dosage forms were stable for at least 90 days at 37 degrees C (loss of potency of 5%). According to FDA guidelines, a tentative expiry date of 2 years at 25 degrees C is justifiable.

Acetazolamide↗
PubMed1989

Preformulation studies of acetazolamide: effect of pH, two buffer species, ionic strength, and temperature on its stability.

Using an HPLC method, the effect of pH, two buffer species (phosphate and citrate), ionic strength, and temperature on the stability of acetozolamide has been studied. The optimum pH of stability appears to be 4. The buffers and ionic strength did not affect the decomposition constant. There was a direct relationship between the activation energies and pH values, with an energy of activation (Ea) value of 16.61 kcal/mol at pH 4. The un-ionized acetazolamide is subject to specific acid-base catalysis. The KH and KOH values have been estimated to be 0.23 and 1.56 d-1, respectively. These preformulation studies can be used to develop a stable oral liquid dosage form of acetazolamide.

Acetazolamide↗
PubMed1988

Chemical stabilities of isoetharine hydrochloride, metaproterenol sulphate and terbutaline sulphate after mixing with normal saline for respiratory therapy.

The chemical stabilities of isoetharine hydrochloride inhalation solution, metaproterenol sulphate inhalation solution and terbutaline sulphate injection, after diluting 1 in 10 with sodium chloride 0.9% injection were studied. On storing the solutions in amber-coloured syringes, they were stable for at least 120 days at 5 degrees C. At 25 degrees C they were also stable for 120 days except that isoetharine solution discoloured and lost 7.8% of its potency after 90 days of storage. There was a new peak in the chromatogram from the decomposition product. All other solutions remained clear for 120 days at both temperatures. The initial and final pH values were similar except that after 120 days at both temperatures. The initial and final pH values were similar except that after 120 days at 25 degrees C, the pH value of terbutaline solution had increased from 4.9 to 5.4.

Amino Alcohols↗
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↗
PubMedDate not supplied

Particulate contamination from siliconized rubber stoppers--a statistical evaluation.

Siliconized stoppers, when used with parenteral drug products, have been shown to be a source of particulate contamination. In this study, five different variables: pH of the solution, buffer concentration, Teflon coating on the stopper, autoclaving cycle (F0), and lot-to-lot variation of the siliconization process were evaluated using an eight-run Plackett-Burman design with respect to their impact on the level of particulate contamination from siliconized stoppers. Results show that pH of the solution can significantly affect the particulate level of samples using siliconized stoppers (p < 0.05). An alkaline solution (pH = 8) was shown to produce a higher particulate load than an acid solution (pH = 4). The main effect of the remaining four variables was determined to be statistically insignificant (p > 0.15).

Analysis of Variance↗