Safety and efficacy evaluation of plain OTC-HCL in acute and subacute toxicity tests and infected mice

The study aimed to evaluate the safety and efficacy of plain Oxytetracycline hydrochloride (OTC-HCL) in mice experimentally infected with 544 strain. The safety of plain OTC-HCL was assessed through acute and subacute toxicity testing. The LD value was determined, and hematologic, biochemical, and histopathological analyses were performed. For efficacy evaluation, mice were intraperitoneally injected with 3 × 10^6 CFU of 544 in 0.5 ml. Following infection, the mice received 25 mg/kg of plain OTC-HCL intravenously either daily or on alternate days for 21 days, starting from day 14 post-infection. Efficacy was assessed by measuring the logarithmic decrease in counts in the liver, lymph nodes, and spleen on days 1, 7, and 14 after treatment. Plain OTC-HCL has an LD of greater than 250 mg/kg. In both acute and subacute toxicity evaluations, the hematologic and biochemical data of the drug were within the normal range. Histopathology studies revealed no significant changes in the safety studies. In the subacute toxicity study, the drug was administered to mice received plain OTC-HCl @ 25 mg/kg intravenously for 21 days. Efficacy was measured by the decrease of counts in the liver, lymph nodes, and spleen. Plain OTC-HCL was found to be safe in both acute and subacute toxicity tests and effectively reduced the infection load of in mice. Our findings and novelties are 1) LDis more than 250 mg/kg for plain OTC-HCL by intravenously as a single dose. 2) Histopathology indicates that there is no organ toxicity for plain OTC-HCL in safety studies. 3) Plain OTC-HCL was found to be effective in reducing the infection load in -infected mice.