Pharmacoscintigraphy : An Unexplored Modality In India
Establishment of a new molecule as a therapeutic agent requires extensive inputs in terms of money, energy and time. Therefore the worldwide pharmaceutical R and D are focusing its attention on the development of new drug delivery systems. After designing a new delivery system, its optimization Involves the in vitro and in vivo studies. Pharmacopoeial dissolution testing is an important in vitro test to study the release of the drug from its formulation. In vivo studies can be carried out either by blood sampling method or urine analysis. Besides, being cumbersome and tedious these methods do not give any information regarding the biopharmaceutics. Pharmacoscintigraphy, a much-touted technology can answer all above-mentioned queries regarding a delivery system. g-Emitting radionuclide (preferably 99mTc) is tagged with the active constituent or the excipient of the formulation. The radioactive dosage form is administered via Intended route of administration and the subject (humans/animals) is scanned under a gamma camera. Radionuclides tagged with drugs/formulations/devices can provide vital information regarding the extent, rate, site, and mode of drug release and morphology of the drug delivery system during release in humans under the ethical norms. Pharmacodynamics and pharmacokinetics of new drug molecules studied by this technique gives qualitative as well as quantitative data. Present study proposes an effective approach for the development and evaluation of new drug molecules and drug formulations.