Pharmacokinetic Evaluation of Ofloxacin in an Invertebrate Animal Model Silkworm, Bombyx mori

Abstract We propose silkworm as an animal model for screening the drug molecules, especially antibiotics, because they exhibit a conserved immune response and similar pharmacokinetics (PK) as mammals and importantly no ethical issues are associated. To evaluate the PK parameters and effectiveness of ofloxacin in silkworm. Silkworms with their ideal body weight of 3.8 g were injected with 40 μL of 2 mg/mL ofloxacin. The hemolymph was collected at different time intervals 0 to 300 minutes. The samples were used for estimating the retention of ofloxacin in silkworm hemolymph by high performance liquid chromatography (HPLC), ultra violet visible (UV-VIS) spectrophotometry, liquid chromatography mass spectroscopy (LC-MS), and Fourier transform infrared spectroscopy (FTIR). PK analysis was performed by using the PK solver MS-Excel add-on software. The HPLC method was standardized for the quantification of ofloxacin in silkworm. Further with reference, the structure of ofloxacin was elucidated on the basis of LC-MS spectral data. We reconfirmed the presence and activity of the ofloxacin in silkworm by UV-VIS spectrophotometry and FTIR spectroscopy. The noncompartmental analysis technique was used to quantitatively evaluate and predict the in vivo fate of drug by modeling the concentration time–data with suitable model. The features of the silkworm described suggest that they are a suitable alternative evaluation model for determining the therapeutic effectiveness of candidate drugs. The availability of a large number of silkworms at low cost and no associated ethical issues makes it a better animal model suitable to screen novel antibiotics for their therapeutic effectiveness.