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Biomedical subjects

V K Dixit

Publications and source records attributed to V K Dixit.

At least 37 records · Page 2Linked to original sources
PubMed1998

The role of mixed micelles in drug delivery. I. Solubilization.

The present study revealed that the solubilization of a poorly soluble drug, Amphotericin-B (AmB) can be improved by lipid-bile salt mixed micelles and it was also noted that mixed micellar systems are thermodynamically stable relative to micellar systems. It was observed that the degradation or precipitation of AmB was significantly reduced when stored at 8 degrees C. The mixed micellar systems composed of sodium desoxycholate with monoolein increased the solubilization of AmB by more than seven-fold as compared to nonmicellar systems.

Amphotericin B↗
PubMed1993

Obstructive jaundice--a diagnostic appraisal.

One hundred and eight suspected cases of obstructive jaundice (OJ) were analysed using ultrasonography, percutaneous transhepatic cholangiography (PTC) or Endoscopic retrograde cholangiopancreatography (ERCP) or both. Clinical evaluation had accuracy of 93% in identifying OJ and establishing aetiology in 62%, however, it lacked specificity. Ultrasonography was useful in differentiating obstructive jaundice from medical jaundice in 91% of cases. However, the cause and site of biliary obstruction could be identified in 55% and 46% respectively. PTC was helpful in detecting the site of obstruction in 80.4% and nature in 63% of cases. Its failures were mostly associated with the presence of metastasis in the liver. ERCP successfully attained cholangiography in 58% and pancreatogram in 70% of cases. Overall diagnostic yield of ERCP was 67% in view of additional endoscopic findings in 18 cases. The complications were occasional and could be managed effectively with medical treatment. This study suggests utility of clinical evaluation in OJ inspite of its poor specificity and comparative value of PTC and ERCP in establishing the site as well as nature of lesion.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1993

Splenic hemangiomatosis with osseous involvement.

A rare case of splenic hemangiomatosis with bone involvement in the upper extremity is presented. The findings on ultrasonography and CT scan abdomen were suggestive of splenic hemangiomatosis. X-ray of left forearm showed findings characteristic of osseous hemangiomatosis, which was subsequently confirmed on histology.

Adult↗
PubMed1992

Endoscopic sphincterotomy: preliminary experience at a university hospital.

Endoscopic sphincterotomy (ES) was attempted in 38 patients with biliary calculi. There were 21 patients (55.3%) with common bile duct (CBD) stones following cholecystectomy, 14 patients (36.8%) with intact gall bladder and 3 patients with retained CBD stones along with T tube in the early post-operative period. Endoscopic sphincterotomy was possible in all but one patient and duct clearance was attained in 34 (89.4%) patients. Spontaneous clearance of calculi occurred in 31 (81.6%) patients while 3 patients required instrumental extraction. Four patients failed to clear stones and required surgical intervention. Complications occurred in 4 (10.5%) patients--haemorrhage in two, pancreatitis and cholangitis in one each. One patient died of bleeding on the 4th day following ES while hemostasis was achieved in other after two units of blood. Other complications were managed conservatively without any mortality. Endoscopic sphincterotomy appears to be a simple, effective and safe therapeutic modality for the management of biliary calculi.

Adolescent↗
PubMedDate not supplied

Effervescent granule based proliposomes of ibuprofen.

Proliposomes of ibuprofen were successfully prepared using effervescent granules as solid carriers of dried phospholipids along with other lipids (soyabean lecithin, stearylamine and cholesterol). Liposomes of regular size with uniform size distribution resulted when proliposomal formulations were hydrated under the effervescence produced by the production of carbon dioxide gas. The inert atmosphere of carbon dioxide gas prevents the chance of oxidative degradation of phospholipids. The size distribution of liposomes was noted to be related to the degree of agitation provided by effervescence. Encapsulation efficiency of liposomes derived from proliposomes was shown to be nearly 100 per cent. Preparations were shown to be quite stable at 20 degrees C when stored under an umbrella of nitrogen. The enhanced anti-inflammatory activity of ibuprofen entrapped in liposomes was exhibited when compared with plain ibuprofen following intravenous administration using the carrageenan induced paw oedema test.

Animals↗
PubMedDate not supplied

Proliposomes of indomethacin for oral administration.

Indomethacin, a non-steroidal anti-inflammatory drug was encapsulated into liposomes composed of soyabean lecithin, cholesterol and stearylamine for oral administration. Liposomes of homogenous size distribution and higher entrapment efficiency were derived from effervescent granule based proliposomes. The efficacy of the oral route was studied by measuring ulcerogenic index and anti-inflammatory activity using carrageenan induced paw oedema test in rats. The effervescent granule based liposomal products exhibited improved in vivo performance with reference to their cytoprotective and anti-inflammatory activities.

Administration, Oral↗
PubMedDate not supplied

Hydroxy-urea bearing albumin microspheres--preparation, characterization and evaluation.

Hydroxy-urea bearing albumin microspheres were prepared using the polymer dispersion method. Glycerol was used successfully in place of water as an internal phase of w/o emulsion, to prepare HSA based albumin microspheres. Silicone coated magnetite of nanometeric size was incorporated in the drug bearing microspheres. The process variables which could affect the physical characteristics with respect to in vitro and in vivo performance of the prepared microspheres were studied. The in vitro release of the drug from the microspheres followed a linear relationship when commulative per cent drug release was plotted against square root of time. Microspheres of average size 1-4 microns were studied for in vivo distribution and localization. It was established that 67 per cent of the drug enveloped in magnetic albumin microspheres could be localized in a rat tail target segment, on applying an external magnetic field of strength 8000 Oe. A remarkable stabilization of hydroxy urea in the prepared microspheres was recorded when t10% drug degradation was compared with the albumin microspheres prepared by a conventional emulsion polymerization method using water as an internal phase.

Animals↗
PubMedDate not supplied

Localized rifampicin albumin microspheres.

Rifampicin bearing albumin microspheres were prepared. The process variables which could affect the physical characteristics and in vitro release of the drug from the microspheres were optimized. Changes in the original size of the microspheres, namely swelling on exposure to buffer solution pH 7.2 and serum, were monitored. In vivo distribution studies on prepared microspheres revealed that 62 per cent of the drug could be localized in the lungs by controlling microsphere size. Hence, rifampicin bearing albumin microspheres can behave as a reservoir to build up higher local drug concentrations.

Animals↗
PubMedDate not supplied

Enteric spherules diastase in enzyme preparations.

Enteric diastase spherules were prepared using cellulose acetate phthalate and eudragit RS-100 by emulsion solvent removal method. Factors that could affect the size shape and diastatic activity were studied. The studied factors include pH of aqueous media, temperature of dispersion media and concentration of surface active agent. Prepared enteric diastase spherules were investigated for stability and diastatic activity at different temperatures and pH in various buffer systems, in the presence and absence of pepsin, a gastric enzyme. Eudragit RS-100 based spherules were noted to be spherical and uniform in shape with an appreciable level of diastatic activity. However, diastase was observed to be released from such a system in a slow but controlled manner. Eudragit RS-100 was found to provide more stabilization to the diastase than the stabilization provided by cellulose acetate phthalate. The spherules when tested in in vitro and in situ were recorded to exhibit diastatic activity at 99 per cent potency level (based on an actually incorporated amount of diastase). The study reveals that enteric or pH sensitive diastase releasing systems hold promise and potential in the therapeutic application of digestive enzyme(s).

Acrylic Resins↗
PubMedDate not supplied

Preparation and performance evaluation of plain proliposomal systems for cytoprotection.

Plain liposomal systems composed of soyabean lecithin, cholesterol and stearylamine were formulated using various approaches. The prepared products were characterized and evaluated for their cytoprotective performance against the necrotizing NSAID's (i.e. aspirin and phenylbutazone). Liposomes derived from proliposomes (effervescent granules based) demonstrated the best cytoprotective activity and physical and stability characteristics. This system was shown to be superior. An increased availability of regular and small sized liposome born phospholipids to the damaged mucosal systems accounted for its better and enhanced performance.

Animals↗
PubMedDate not supplied

Enhanced in vivo performance of liposomal indomethacin derived from effervescent granule based proliposomes.

Indomethacin, a non-steroidal anti-inflammatory drug was successfully entrapped into liposomes (soyabean lecithin, cholesterol, stearylamine or dicetylphosphate) with uniform size distribution. The liposomal vesicles were derived from dried effervescent granule-based proliposomes. The in vivo distribution characteristics of the reconstituted liposomal indomethacin was studied in normal rats and in the rats with inflamed paws following intravenous administration. The localization of the liposome-based indomethacin was in liver, lungs and inflamed tissues (inflamed rats studies). Further, an enhanced anti-inflammatory activity of lipo-indomethacin was found as compared with the activity recorded for plain drug in carrageenan induced paw oedema in rats.

Animals↗
PubMedDate not supplied

14C-urea breath test for assessment of gastric Helicobacter pylori colonization and eradication.

BACKGROUND AND OBJECTIVE: Urea breath test (UBT) is a reliable noninvasive technique for detecting gastric Helicobacter pylori colonization. 14C isotope-based test requires simple equipment and is inexpensive. We studied the utility of 14C-UBT in diagnosis of gastric H. pylori infection. METHODS: Presence of H. pylori was studied using antral histology and culture in patients with rapid urease test (RUT)-positive peptic ulcer. 14C-UBT was performed using a 185-kBq dose. Radioactivity in 15-min breath samples was measured using a beta-scintillation counter and result expressed as % dose recovered/mmol CO2. H. pylori was considered positive when any two tests were positive. All tests were repeated one month after completion of H. pylori eradication therapy. RESULTS: Among 41 patients (duodenal ulcer 36, gastric ulcer 5), H. pylori was detected by histology in 23 (56%) and by culture in 27 (66%). Overall, H. pylori was detected in 28 (68%) patients. Follow-up assessment was possible in 28 patients: 26 cleared the infection (all three tests negative). Mean 14C recovery values at 15 minutes associated with H. pylori-positive status were significantly higher (12.3 [SD 6.8] x 10(-3); n=30; p<0.001) than those associated with H. pylori-negative status (2.1 [0.9] x 10(-3); n=26). Using receiver-operating-characteristic analysis of 15-minute 14C recovery values, a cut-off of 6.5x10(-3) gave the best separation of H. pylori-positive and -negative cases. 14C-UBT had 93% sensitivity, 96% specificity and 95% accuracy. CONCLUSION: 14C-UBT appears to be a reliable noninvasive test for diagnosis of H. pylori infection.

Adolescent↗