Retinal bioavailability of a DHEA synthetic analog after intraperitoneal administration in the Sprague Dawley rat

Purpose To evaluate the retinal bioavailability of a synthetic Dehydroepiandrosterone (DHEA) analog, a molecule with potential anti‐apoptotic action, after systemic administration. Methods 25 Sprague Dawley rats were injected intraperitoneally with 10 mg of the analog in1 ml of an ethanol/Water For Injection (WFI) solution. The synthetic neurosteroid was injected in 3‐5 rats at each time point at the same concentration every time. The animals were euthanized at 15, 30 min and 1, 2, 4, 6 & 24 hrs. The eyes were enucleated and the retina was isolated from the eye cup with an eye sponge with suitable handling. After appropriate preparation, the samples were measured with HPLC LC/MS. Results The recovery of the method was 91.4%. The Limit Of Quantification (LOQ) was 0,05 ng/mg. The substance was detected at 30, 60, 120 and 240 min in mean concentrations of 0.10 ng/mg, 0.42 ng/mg, 0.91 ng/mg & 0.17 ng/mg respectively. No substance was detected with this method at 15 min, 6 & 24 hrs. No substance was detected in all blind samples Conclusion The synthetic DHEA analog was successfully detected in the rat retina with an LC/MS HPLC method. The molecule seems to reach the retina in thirty minutes after systemic administration and is still detected there after four hours. Further investigation is obligatory for complete data of the pharmacokinetics of the substance in the rat retina.