Biomedical subjects

J Balasubramaniam

Publications and source records attributed to J Balasubramaniam.

15 recordsLinked to original sources

PubMed2006

Development and evaluation of a novel floating in situ gelling system of amoxicillin for eradication of Helicobacter pylori.

The aim of this study was to develop a new intra-gastric floating in situ gelling system for controlled delivery of amoxicillin for the treatment of peptic ulcer disease caused by Helicobacter pylori (H. pylori). Gellan based amoxicillin floating in situ gelling systems (AFIG) were prepared by dissolving varying concentrations of gellan gum in deionized water containing sodium citrate, to which varying concentrations of drug and calcium carbonate, as gas-forming agent, was added and dissolved by stirring. The formulation variables like concentration of gellan gum and calcium carbonate significantly affected the in vitro drug release from the prepared AFIG. The in vivo H. pylori clearance efficacy of prepared AFIG in reference to amoxicillin suspension following repeated oral administration to H. pylori infected Mongolian gerbils was examined by polymerase chain reaction (PCR) technique and by a microbial culture method. AFIG showed a significant anti-H. pylori effect in the in vivo gerbil model. It was noted that the required amount of amoxicillin for eradication of H. pylori was 10 times less in AFIG than from the corresponding amoxicillin suspension. The results further substantiated that the prepared AFIG has feasibility of forming rigid gels in the gastric environment and eradicated H. pylori from the gastrointestinal tract more effectively than amoxicillin suspension because of the prolonged gastrointestinal residence time of the formulation.

Amoxicillin↗

PubMed2003

Dissolution, bioavailability and ulcerogenic studies on piroxicam-nicotinamide solid dispersion formulations.

Solid dispersions with different ratios of Piroxicam and Nicotinamide (as a carrier) were prepared by fusion method. Drug-carrier interactions in the solid state were ascertained using phase-diagram, X-ray diffraction (XRD) and Differential scanning colorimetry (DSC). Select ratios of the formed piroxicam-nicotinamide solid dispersions and their corresponding physical mixtures were formulated into tablets and capsules. The dissolution characteristics of the formed solid dispersions, physical mixtures and their formulations were compared with pure piroxicam in 900 ml of 0.1 N HCl (pH 1.2) at 37 +/- 0.5 degrees C, 50 rpm using USP XXI paddle apparatus. Solid dispersion capsule PNC1 (containing 1:5--drug-carrier ratio solid dispersion) and the corresponding physical mixture capsule PNC1A were used for bioavailability studies in healthy human volunteers. Further, ulcer indices of the prepared solid dispersion and their corresponding physical mixture were compared with pure piroxicam in rats. The DSC, XRD and phase diagram indicated the formation of solid dispersed system. The prepared dispersion showed better dissolution than the corresponding physical mixture and pure drug. The fabricated formulation complied with the pharmacopoeial limits for physico-chemical properties and the solid dispersion capsules PNC1 and PNC2 (containing 1:9 ratio of drug to carrier solid dispersion) showed 3 and 6.6 fold increase and 3.2 and 8 fold increases in dissolution rate compared to the corresponding physical mixture capsules (PNC1A and PNC2A), respectively. The solid dispersion capsule PNC1 showed significantly higher absorption and dissolution and consequently better bioavailability than the corresponding physical mixture capsule (PNC1A) in healthy human volunteers. The ulcer indices of the prepared dispersions were significantly lower than the corresponding physical mixture and pure drug.

Animals↗

PubMed2001

Evaluation of a new screening test for sickle cell haemoglobin.

A new kit for screening for sickle cell haemoglobin (haemoglobin S) has been evaluated. The kit is based on the principle that cells containing haemoglobin S, which have been induced to sickle by exposure to a reducing agent in a phosphate buffer, do not pass through a gel contained in microtubules. In theory, they can thus be distinguished from cells that do not contain haemoglobin S. In practice, the kit was found to be insensitive and unreliable for the detection of haemoglobin S. Homozygosity and heterozygosity for haemoglobin S could not be reliably distinguished. Similarly, patients with haemoglobin S who had been transfused could not be distinguished reliably from those who had not been transfused. In conclusion, unless improved performance can be demonstrated, use of this kit cannot be recommended.

Anemia, Sickle Cell↗

PubMed2001

In vitro and in vivo characterization of scleral implants of indomethacin.

Scleral implants of indomethacin with sodium alginate as carrier were fabricated and evaluated for various physico-chemical properties such as uniformity of thickness, weight, drug content, surface pH, percent dissolution and water up-take capacity (swelling index). The effect of drug particle size, polymer concentration, drug loading, plasticizer concentration, and effects of physical reinforcement (freeze-thawing for 3 and 6 cycles) and chemical cross-linking with calcium chloride, on the in vitro drug release characteristics were evaluated. Selected batches of the implants were subjected to pharmacodynamic studies, after scleral placement, in uveitis induced (intravitreal injection of Bovine Serum Albumin (BSA)-50 micrograms/ml) rabbit eyes. The release of indomethacin from the prepared implants followed predominantly matrix diffusion kinetics. Swelling and moisture absorption/loss studies correlated well with the in vitro release studies. The pharmacodynamic studies showed a marked improvement in the various clinical parameters (congestion, keratitis, flare, clot, aqueous cells and synechias), in the implanted eye when compared to the control eye in the rabbits.

Alginates↗

PubMed2000