The Preparation And Initial Pharmacodynamics Mechanism Study Of Levodopa Methyl Ester Hydrochloride Eye Drops

Objective: To prepare levodopa methyl ester hydrochloride(LDME) eye drops, study its quality, establish the quality standard, and invest their quality stability; To study the pharmacodynamic action for amblyopia treatment, and approach the mechanism of molecular action, to provide basis on experiment and rationale for clinical application.Methods: The influence of pH on the stability of LDME solution was investigated by classic homoiothermic acceleration test. To determine its Hydrolyzation rate constant , activation energy and the pH for the stablest solution. To determine the dosage form and preparative method. The content of LDME was determined by RP-HPLC. The stability of its was tested by accelerated stability test and long-term stability test. We used nNOS antibody to observe the expression and variation of nNOS in dLGN and visual cortex 17 area of the rats with monocular deprivation before and after drug treatment, then approached the changes of neural activity level in visual center, providing the demonstration of pharmacodynamic action.Results: LDME was made into powder, prepared with buffer solution together before using. The average recovery and RSD of HPLC were 100.44%, 1.78%; in the stability experiment, the content of LDME in eye drops was stable, and other quality indexes had no apparent change. The results of immunohistochemistry showed that LDME eye drops increase the expression of nNOS, recovery the functional status of central neuron of the rats with monocular deprivation.Conclusion: The preparative method is simple and reasonable. The quality standard is stable, reliability and can be applied to control effectively the quality of eye drops. The eye drops can increase the expression of nNOS, recovery the functional status of central neuron of the rats with monocular deprivation.