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Biomedical subjects

N K Jain

Publications and source records attributed to N K Jain.

At least 73 records · Page 4Linked to original sources
PubMed1998

Antinociceptive effect of sumatriptan in mice.

Antinociceptive effect of the antimigraine drug sumatriptan (5-HT1A agonist) was studied against acetic acid-induced writhing in mice. Sumatriptan produced the effect in a dose-dependent manner (1, 5, 10 and 20 mg/kg, s.c.). Naloxone (1 mg/kg i.p.) an opiate antagonist failed to reverse sumatriptan-induced antinociception. Cholinomimetic physostigmine (0.05 mg/kg, i.p.) potentiated and the muscarinic antagonist atropine (5 mg/kg, i.p.) blocked the antinociceptive effect of sumatriptan, respectively. The antinociceptive effect of sumatriptan was compared with an another 5-HT agonist (5-HT1A) buspirone which also produced antinociception. Like sumatriptan-analgesia, the buspirone response was also potentiated by physostigmine in atropine sensitive way. Further, buspirone potentiated the analgesic effect of sumatriptan. These observations suggest that 5-HT1A agonists produce antinociception possibly by modulating central cholinergic activity.

Animals↗
PubMed1998

Iontophoretic transdermal delivery of salbutamol: methyl-orange ion-pair.

The influence of pulsed current duty cycle, addition of electrically neutral species and pH on iontophoretic transdermal delivery of an organic ion-pair salbutamol:methyl orange through excised rabbit abdominal skin is described. It was compared with salbutamol sulphate and salbutamol:sulphate ion-pair. It was found that there exists an optimum duty cycle range (1:3-1:4) at which iontophoretic flux of the ion-pair was at a maximum because of partition-electric current synchronization. Addition of mannitol decreases the flux of the ion-pair showing the important role of electroosmosis in ion-pair transport. The extremes of pH decrease the flux rates.

Administration, Cutaneous↗
PubMed1997

Evaluation of an aqueous injection of ketoprofen.

The increase in aqueous solubility of ketoprofen using hydrotropes and cosolvents in formulation, as well as stability studies of its aqueous injections have been reported earlier. These formulations were further evaluated in vitro (physical evaluation, haemolytic activity) and in vivo (pharmacokinetic studies). Some of the formulations have shown promising results.

Administration, Oral↗
PubMed1997

Formulation of an aqueous injection of flurbiprofen.

Flurbiprofen (1) is an analgesic, antipyretic and antiinflammatory agent which is practically insoluble in water. The aqueous solubility of 1 using various hydrotropes was attempted. The solubility increased up to 63 times in the case of sodium benzoate. Using selected hydrotropes, aqueous injections of 1 were formulated. Formulations were studied for physical and chemical stability. Some of the formulations showed reasonable stability which can be further enhanced by incorporation of appropriate formulation additives. These formulations were evaluated for antiinflammatory and analgesic activity and showed promising results.

Administration, Oral↗
PubMed1996

Slide agglutination test for the diagnosis of pulmonary and extra-pulmonary tuberculosis.

OBJECTIVE: Evaluation of a 2 min slide agglutination test to detect the presence of antibodies directed against Mycobacterium tuberculosis antigens. DESIGN: The test utilizes solible antigens extracted from a cultivable new species of non-pathogenic saprophytic mycobacterium, Mycobacterium w, which shares antigenic determinants with M. tuberculosis. The soluble antigens are covalently linked to carboxylated polystyrene latex beads. RESULTS: The sensitivity of the assay was increased from 78% (reported earlier), to 90.2% for pulmonary tuberculosis and 85.7% for extra-pulmonary tuberculosis. The specificity of the test was determined by testing the sera of apparently healthy controls, and patients with other respiratory tract infections and rheumatoid arthritis. Among the apparently healthy controls, 7.3% tested positive. None of the sera from the patients with other diseases gave positive agglutination. CONCLUSION: This simple and rapid technique could be suitable for mass screening for pulmonary and extrapulmonary tuberculosis.

Adolescent↗
PubMed1996

Targeting of multiple emulsions to the lungs.

The conventional W/O/W emulsions are readily taken up by the reticuloendothelial system (RES) so that it is necessary to develop either stealth type or tissue specific multiple emulsion for effective targeting. A multiple emulsion system W/O/W containing rifampicin as encapsulant (W/O/W) was prepared. The droplet size was kept small to study targeting independent of passive embolism of larger droplets in the lung capillaries. It was characterised in vitro for drug release through a treated cellophane membrane. A prolonged first order drug release was observed. The W/O/W multiple emulsion system was coated with an o-palmitoyl derivative of mannan (mol.wt. 20,000) to assess its toxicity in vitro and its distribution behaviour in vivo. The multiple emulsion was found to be non toxic at 0.2 ml formulation/10(6) cells level in presence or absence of serum. An intravenous injection of the polysaccharide coated multiple emulsion was given and the tissue distribution of the drug after 1 h and 24 h was investigated. A significant enhancement in lung uptake and a decreased internalisation by spleen was noticed.

Animals↗
PubMed1996

Cosolvent solubilization and formulation of an aqueous injection of ketoprofen.

Ketoprofen (1) an analgesic, antipyretic and anti-inflammatory agent, is practically insoluble in water. An increase in the aqueous solubility of 1 was attempted by various cosolvents. The solubility increased up to 8556 times (maximum) in case of ethanol while it was 33 times (minimum) in case of glycerol. Using selected cosolvents and hydrotropes, aqueous injections of 1 were formulated.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1995

Self assembling nanostructures for sustained ophthalmic drug delivery.

Nanopseudolatex was prepared for sustained ophthalmic delivery. It was prepared by a solvent injection method without the use of any stabilizer. The acrylate copolymers Eudragit RLPM and RSPM were used as carrier materials. Their formation was confirmed by electron microscopy. The system was extensively characterized for particle size, viscosity, sedimentation volume, encapsulation efficiency, in vitro release profile and pharmacodynamic properties. The particle size was found to be stirring rate dependent above the injection rate of 1 ml/min. Only at slow stirring rates it was temperature dependent. There was no sedimentation for about 60 d. The viscosity was 23-27 cps which was particle size dependent. The results show an excellent encapsulation efficiency of about 94-98%. Release studies showed slow and consistent drug release from the formulation. However, Eudragit RSPM showed comparatively longer release than Eudragit RLPM nanosuspensions. Using this method we have developed a new formulation of diclofenac diethyl ammonium which showed increased therapeutic efficacy as compared with eye drops.

Acrylic Resins↗
PubMed1993

Is combined therapy of sympathomimetics and theophylline indicated?

Bronchodilator effect and toxicity of theophylline 300 mg twice a day (R1), salbutamol 4 mg tid (R2), their combination in higher (200/4mg, R3), and lower doses (100/2mg R4), and placebo (calcium lactate 300 mg) tid (R5) were compared in 25 patients with bronchial asthma in a randomized crossover trial. Statistically significant improvement in forced expiratory volume in one second (FEV1) was observed in all the active treatment groups (R1 to R4) compared with placebo (R5). The mean improvement in FEV1 was 29.0%, 22.0%, 28.0%, 30.0%, and 0.73% in regimen R1, R2, R3, R4, and R5, respectively day 1, and corresponding improvement was 30.0%, 24.0%, 29.0%, 34.0%, and 4.4% on completion of one week therapy. On intergroup statistical comparison, mean improvement in pulmonary function test values were statistically significant or highly significant in regimens R1 to R4, as compared with placebo. However, improvement between any two regimens was not statistically significant in any of the regimens (R1-R4). Almost all the regimens were tolerated well and no patient showed major adverse reactions or cardiotoxicity necessitating withdrawal of the drug. On the other hand, minor adverse reactions were common and the high dose combination (R3) was found to have more adverse reactions than the low dose combination and either drug used alone.

Adolescent↗
PubMed1993

Passive vectoring of a colloidal carrier system for sodium stibogluconate: preparation, characterization and performance evaluation.

The intracellular residence of the Leishmania parasite in the cells of the reticuloendothelial system--predominantly the liver and spleen--prompted the development of a polymeric, particulate, colloidal carrier system for the antileishmanial drug sodium stibogluconate. The system was pharmaceutically characterized for shape, size, structural integrity, electrokinetic properties and in vitro drug release. The relationship between such physical parameters as size, electrophoretic mobility and surface charge and the effectiveness of the system is discussed. Subsequent in vivo studies in rats revealed that the carrier system successfully vectored the drug to the site of infection.

Animals↗
PubMed1992

Controlled-release tablet formulation of isoniazid.

Guar (GG) and Karaya gums (KG) alone and in combination with hydroxy-propylmethylcellulose (HPMC) were evaluated as release retarding materials to formulate a controlled-release tablet dosage form of isoniazid (1). In vitro release of 1 from tablets followed non-Fickian release profile with rapid initial release. Urinary excretion studies in normal subjects showed steady-state levels of 1 for 13 h. In vitro and in vivo data correlated (r = 0.9794). The studies suggested the potentiality of GG and KG as release retarding materials in formulating controlled-release tablet dosage forms of 1.

Adult↗
PubMed1991

The ileum and carbohydrate-mediated feedback regulation of postprandial pancreaticobiliary secretion in normal humans.

We investigated the effect of perfusing carbohydrate into the ileum on postprandial pancreaticobiliary secretion and the relationships among carbohydrate in the ileum, pancreaticobiliary secretion, and gastric emptying. Eighteen healthy volunteers were intubated with a multilumen oroileal tube. A metal labeled with 111In-diethylenetriamine-pentaacetic acid (400 calories; 60% carbohydrate, 20% protein, 20% fat) was then infused into the stomach, and a carbohydrate solution (rice starch + glucose) was perfused into the terminal ileum at rates (mg/min) of 0 (saline; n = 6), 12.5 (n = 4), 25 (n = 4), 50 (n = 2), and 100 (n = 2). To prevent digestion of the carbohydrate in the ileum, an amylase inhibitor (3.3 mg/ml) was added to the perfusate used in half of the subjects. Postprandially, we measured outputs of amylase, trypsin, and bile acids in the duodenum, the amount of carbohydrate in the ileum, and gastric emptying. During the second postprandial hour the rate of gastric emptying was inversely related to the amount of carbohydrate in the ileum (p less than 0.01) and was directly correlated with pancreaticobiliary secretion (p less than 0.05). However, as the amount of unabsorbed carbohydrate in the ileum increased, the ratio of amylase to trypsin secretion increased (p less than 0.005). Postprandially carbohydrate in the ileum induces changes of upper-gut function that should increase digestion and absorption of carbohydrate since gastric emptying (and delivery of carbohydrate to the duodenum) slows and pancreatic amylase secretion increases relative to trypsin secretion and gastric emptying.

Adult↗
PubMed1990

Diarrhea in diabetics: the role of sorbitol.

Diabetics often consume dietetic foods with sorbitol as the sweetener. Sorbitol, in amounts as little as 10 g. may produce diarrhea in healthy individuals. Sorbitol intolerance was studied in 12 diabetics and 23 nondiabetics. Similar numbers of diabetics (n = 10, 83.3%) and nondiabetics (n = 18, 78.3%) were found intolerant as judged by a greater than or equal to 20 ppm rise in postprandial breath hydrogen levels. Six diabetics (50%) and 13 nondiabetics (56.5%) developed abdominal symptoms after sorbitol ingestion. Subsequently, 100 diabetics and 100 nondiabetics were interviewed to determine the relationship between regular sorbitol consumption and abdominal symptoms. The interview revealed that (1) most individuals consuming sorbitol were unaware of its presence in their diet and (2) diarrhea was significantly (p less than 0.001) more prevalent in diabetics consuming sorbitol than diabetics not consuming it. We conclude that (1) many diabetics are intolerant to sorbitol and (2) regular sorbitol consumption may explain the "idiopathic" diarrhea in some diabetics.

Abdominal Pain↗
PubMed1990

Characterisation of cell-wall-derived polypeptide antigens from different species of Mycobacterium.

Cell walls from different species of Mycobacterium were purified on a sucrose step gradient. The components derived from these preparations were characterised by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, followed by staining or by Western blotting. Surface-exposed polypeptide molecules were also identified by biotinylation. Many protein and glycoprotein molecules were identified in the cell walls. Some of these molecules were immunogenic in man and experimental animals and showed wide variability from species to species. The data suggest that these molecules could be of significance in the diagnosis and pathophysiology of mycobacterial diseases.

Antigens, Bacterial↗