Biomedical subjects

Vinod Arora

Publications and source records attributed to Vinod Arora.

4 recordsLinked to original sources

PubMed2006

Investigation on physicochemical and biological differences of cefpodoxime proxetil enantiomers.

Cefpodoxime proxetil (CP) is a prodrug of cefpodoxime acid (CA), and is supplied as racemic mixture of R- and S-enantiomers. CP has only 50% absolute bioavailability, and the reasons responsible for low bioavailability remain poorly understood. The present work ascertains physicochemical and biological properties of individual isomers of CP and explores their capacity to optimize delivery of CP. Both isomers showed similar pH stability behavior, but R-isomer was more susceptible to enzymatic metabolism compared to S-isomer, when incubated with enzymes collected from various segments of GIT. Based on the in vitro and in vivo results, use of S-isomer for development of a dosage form such as gastro-retentive dosage form can improve oral bioavailability of CP.

Administration, Oral↗

PubMed2006

Investigation of factors responsible for low oral bioavailability of cefpodoxime proxetil.

Learning about the behavior of a drug in biological environment enables application of better formulation strategies to improve bioavailability of the same. Cefpodoxime proxetil (CP) is a prodrug, which is orally administered cephalosporin with only 50% absolute bioavailability. Despite previous studies, reasons responsible for low bioavailability of CP remain poorly understood. The present study tries to ascertain reasons for the low oral bioavailability of CP. The in vitro, in situ and ex vivo studies showed interesting results, where metabolism of CP into cefpodoxime acid (CA) inside the intestinal epithelial cell and preferential efflux of CA into lumen was identified as primary reason for low oral bioavailability of CP. Presence of specific carriers or transportation mechanism on the apical side membrane of enterocyte, than basal side of the same was observed.

Administration, Oral↗

PubMed2005

Unbiased membrane permeability parameters for gabapentin using boundary layer approach.

The present study was performed to determine the relative contribution of both passive and nonpassive transport processes in jejunal absorption of gabapentin. The oral absorption of gabapentin was studied using in situ single pass intestinal perfusion technique in fasted rats. Unbiased intrinsic membrane absorption parameters such as maximal flux, Michaelis constant, carrier permeability, and membrane permeability were calculated using a modified boundary layer model. Gabapentin intestinal perfusion results indicate that its jejunal absorption in rats occurs via a nonpassive process, with no significant passive absorption component, as demonstrated by saturable absorption kinetics and its concentration-dependent permeability. A good correlation (r2 = 0.88) between observed human absorption fraction and calculated (from in situ rat intestine) human absorption fraction was obtained.

Algorithms↗

PubMed2004

Tuberculous gastric perforation: report of a case.

A 21-year-old woman presented with a 2-day history of acute abdominal pain. Contrast-enhanced computed tomography (CT) showed a perforation in the lesser curve of the stomach. The patient suffered a bout of hematemesis, following which an endoscopy showed a bleeding blood vessel at the edge of the perforation. We performed an emergency distal gastrectomy, including the ulcer site. Histopathological examination revealed tuberculous granulation tissue and acid-fast bacilli in the ulcer. The patient was given antituberculosis therapy (ATT) postoperatively, and was well when last seen 1 year 5 months after surgery. We analyzed the clinical data of five cases of tuberculous gastric perforation (TGP), reported between 1948 and 2003, including our patient. The patients ranged in age from 21 to 45 years, with a mean age of 36.8 years (SD +/- 10.21), and a male to female ratio of 3 : 2. The diagnosis was confirmed by surgery or autopsy. Abdominal lymphadenopathy was present in all patients. Gastrectomy was performed in four patients, and two were given ATT. All four patients in the previous reports died of their disease.

Abdominal Pain↗