A Rapid and Precise Reverse Phase High Performance Liquid Chromatographic method has been developed for the validated of Reserpine and Dihydralazine, in its pure form as well as in tablet dosage form. Chromatography was carried out on X-Terra C18 (4.6 x 150mm, 5μm) column using a mixture of Methanol: TEA Buffer pH 4.5: Acetonitrile (65:15:20) as the mobile phase at a flow rate of 1.0ml/min, the detection was carried out at 212 nm. The retention time of the Reserpine and Dihydralazine was 2.090, 5.289 ±0.02min respectively. The method produces linear responses in the concentration range of 5-25mg/ml of Reserpine and 45-225mg/ml of Dihydralazine. The method precision for the determination of assay was below 2.0%RSD. The method is useful in the quality control of bulk and pharmaceutical formulations. Keywords: Reserpine, Dihydralazine, RP-HPLC, PDA detection, Method validation.

Introduction and Objective: Search of a target specific radiopharmaceutical is always on and the development of radiolabeling methods for a target specific bone scintigraphy agent is need of hour for timely management of cancer. Zoledronic acid belongs to a class of drugs known as bis phosphonates. Technitium-99m has good gamma imaging characteristics so it can be good osteoscintigraphy radio pharmaceutical. Analysis the radiation dosimeter is also very important for any radiopharmaceutical. Material and Methods: High grade reagent and radiopharmacy laboratory of Nuclear Medicine department of Bhagwan Mahaveer Cancer Hospital & Research Centre (BMCHRC), Jaipur used. We have procured all the radioisotopes and other chemicals. Radiolabeling has been done as per standard radiochemical reactions. Quality control of radio labeled 99mTc-ZA has been done by chromatographic techniques. Radiation Dosimetry has been done as per guidelines of the radiation survey and monitoring of MIRD. Results/Discussion: We have successful radiolabeled the Zoledronic acid with 99mTc. We have detected 98.55 % radiolableing efficiency of ZA with 99mTc. The radiopharmaceutical can be used for clinical trial and application after further testing. We have also observed good radiation dosimetry parameters for diagnostic use of this radiopharmaceutical. The Radiopharmaceutical can be good nuclear medicine radiopharmaceutical for the osteoscintigraphy. Conclusion: The discussed radiolabeling techniques and methods for technetium labeled Zoledronic Acid has shown good radiolabeling efficiency and good radiation dosimetry characteristics that are very encouraging. It can be used for bone scintigraphy further testing. Keywords: Zoledronic Acid (ZA), Acid, Osteoscintigraphy, SPECT, Bisphosponate, ITLC, Dosimetry.