Measurement and Analysis of the Half-Life of Some Viable Anti-Malaria and Analgesic Drugs

Abstract

This paper is experimental research which focuses on the determination of the pharmaceutical half-life of some analgesic and anti-malaria drugs using the volume of distribution and clearance of the pharmacokinetic processes. Some analgesic and anti-malaria drugs were collected and administered to six healthy young men. Blood and urine samples were collected from each of them after one hour from the time of administration. All the samples for each drug were separated using a Gas chromatography machine to obtain the amount of drug remaining in the blood and the amount eliminated. The obtained values for the volume of distribution (Vd) from the blood samples and clearance (Cl) from the urine samples where mathematically evaluated with the elimination rate constant k=0.693 approximated to 0.7 to give a result with little or no error. The half-life for all samples were obtained and the pharmacokinetic properties and interactions of the drugs analysed. The various half-life obtained from this research certifies and correspond to the manufacturer's published half-life for the analysed drug samples. The high volume of distribution of Tramadol hydrochloride 70l/kg-painkiller, paracetamol 65l/kg-painkiller and artesunate 50l/kg-anti-malarial shows that they are highly absorbed into the body system and are very strong medications. They do not leave the system quickly and affects the physiological state for a long period while the low volume of distribution processes of diclofenac 1.4l/kg-painkiller, arthemeter 11.5l/kg-anti-malaria and quinine 28l/kg-anti-malaria shows a low distribution rate of these drugs, and implies they are less strong medications and does not last long in the body with their relative rates of elimination; Diclofenac 0.895l/kg/hr., arthemeter 2.6l/kg/hr. and quinine 2.4l/kg/hr.