Synthesis, characterization and pre-clinical evaluation of (99m) Tc-tricarbonyl complexes as potential myocardial perfusion imaging agents.

Myocardial perfusion imaging is an established Nuclear Medicine investigation. Current myocardial perfusion imaging agents sestamibi and tetrofosmin have number of drawbacks; low heart uptake coupled with uptake into the surrounding tissues leads to a poorer image quality. There is a need for continued research into designing and evaluating potentially superior myocardial imaging agents.

Evaluation of 99mTc(CO)5I as a potential lung perfusion agent.

Introduction: The use of (99m)Tc-macroggregated albumin for lung perfusion imaging is well established in nuclear medicine. However, there have been safety concerns over the use of blood-derived products because of potential contamination by infective agents, for example, Variant Creutzfeldt Jakob Disease. Preliminary work has indicated that Tc(CO)(5)I is primarily taken up in the lungs following intravenous administration.

Citric acid prolongs the gastro-retention of a floating dosage form and increases bioavailability of riboflavin in the fasted state.

A floating dosage form based on calcium alginate beads has been developed. Riboflavin, was selected as the model drug and successfully incorporated into calcium alginate beads. The aims of the current study were to: (a) assess the influence of prolonged gastro-retention on the bioavailability of riboflavin from freeze dried calcium alginate beads administered under varying conditions of food intake and (b) to investigate the potential of citric acid to delay the gastric emptying of the calcium alginate beads.

The use of citric acid to prolong the in vivo gastro-retention of a floating dosage form in the fasted state.

Gastro-retentive dosage forms have the potential to improve local therapy and decrease the variation in bioavailability that is observed with a number of commercially available immediate and modified release preparations. In this study, a dosage form has been developed, utilising freeze-dried calcium alginate beads, designed to float on the surface of the stomach contents thus prolonging the retention time. The aim of the study was to also assess the in vivo behaviour of the radio-labelled calcium alginate beads when they were administered under fasting conditions with either water or an aqueous solution of citric acid, a potential gut transit delaying substance.

Gamma scintigraphic evaluation of film-coated tablets intended for colonic or biphasic release.

The gastrointestinal transit and in vivo drug release behaviour of a film-coated tablet formulation was investigated in five healthy human subjects using the technique of gamma scintigraphy. The film coating system consisted of a mixture of pectin, chitosan and HPMC in a ratio of 6:1:0.37 applied to 750 mg cores at a coat weight gain of 9%.

Autologous lymphocytes as vectors to target therapeutic radiation, using indium-114m, in patients with lymphoid cell malignancy.

Autologous lymphocytes provide a potential vector for the delivery of a cytotoxic agent in patients with lymphoid cell malignancy. This report describes a phase I-II study using autologous lymphocytes to target the radionuclide indium-114m ((114m)In) in patients with refractory chronic lymphocytic leukaemia or small lymphocytic non-Hodgkin's lymphoma. Nineteen patients, the majority of whom had been heavily pretreated with conventional chemotherapy and radiotherapy, received between 69 and 211 MBq (114m)In-labelled autologous lymphocytes.