The present investigation was aimed to prepare aqueous based leaves extract of C. papaya and determine the stability of extracts by adding preservatives on long term storage. The stable extract was considered for haematological changes and clotting time in wister rat. The constituent of papaya leaves was extracted using distilled water. The phytochemical investigation was carried out using standard literature procedure. The stability of extract was determined based on the turbidity of extract. The ability of extract to resistance in microbial growth was determined by agar disc diffusion technique (zone of inhibition) in different strains of bacteria. The haematological parameter like platelet count, RBC and clotting time was determined on wister rat for 21 days. The percentage yield of the extract was 19.5%.The phytochemical investigation proof the presence of tannins, saponins, cardiac glycosides and steroids as a major constituent in the extract. The stability result showed the extract contained propyl paraben and methyl paraben (0.3% v/v) as a preservative are more stable. The efficacy of the extract was determined on wister rat. The body weight of both test and control groups was stable during the trial. This study clearly showed increasing platelet and RBC count in healthy rats after feeding with a short course of papaya leaf extract. The clotting time also increased in the case of the test. without causing any acute toxicity.
