^99mTc‐Doxycycline hyclate: a new radiolabeled antibiotic for bacterial infection imaging

Abstract

Radiolabeled antibiotics are promising radiopharmaceuticals for the precise diagnosis and detection of infectious lesions. Doxycycline Hyclate (DOX) was chosen to investigate new (99m) Tc-labeled antibacterial agent. Ready to use freeze dry kits were formulated with optimum labeling conditions. Human serum stability, sterility, and pyrogenicity of kits were estimated, and gamma scintigraphy, in vivo biodistribution, and histopathological studies with bacterial infected rats were performed. DOX were successfully labeled by (99m) Tc with high radiochemical purity, and the labeled compound was stable in human serum. Kits were sterile, pyrogen-free, and stable up to 6 months. Static images depicted rapid distribution throughout the body and high uptake in bacterial infected thigh muscle. The uptake ratios of radiopharmaceuticals in infected thigh muscle were found above 2 up to 5 h. Five hours after injection, the rats were sacrificed, and biodistribution was determined. Samples of bacterial infected muscle, healthy muscle, blood, liver, spleen, lung, kidney, stomach, intestine, urine and heart were weighed, and the radioactivity was measured by using a gamma counter. The %ID/g of (99m) Tc-DOX was found 0.23 ± 0.06 for infected thigh muscle. According to the imaging, biodistribution, and histopathological studies, the promising characteristics of (99m) Tc-DOX make the new radiopharmaceutical valuable to examine for future studies.

Radioactive Permeability Studies of Doxycycline Hyclate from Microemulsion and Solution

“…Over a period the resulting complex was quite stable and radiochemical purity was found >90 % up to 6 hours without any significant change (p>0.05) (Figure 1). so our results are found to be in compliance with the results of the reference methods (13,14). …”

“…Tc-DOX was prepared using previously published method by İlem-Özdemir et al (13,14). Tc-DOX was prepared from lyophilized cold kit, which is included; 1 mg DOX, 30 µg stannous tartarate and 0.1 mg ascorbic acid.…”

99mTc-Trimethoprim’in Radyosentezi ve Biyodağılımı: Deney Hayvanları Kullanılarak Bakteriyel Enfeksiyon Görüntüleme Için Yeni Bir Radyoişaretli Antibiyotik

“…99m Tclabeled ciprofloxacin, alafosfalin, enrofloxacin, gatifloxacin, cefepime, ceftriaxone, levofloxacin, and cefotaxime were evaluated as an infection imaging agent [27] . Uyaroğlu et al [28] have reported that the 99m Tc-SMX would be developed as a radiopharmaceutical agent to distinguish infection from inflammation by nuclear imaging.…”

Imaging bacteria with radiolabelled quinolones, cephalosporins and siderophores for imaging infection: a systematic review

“…The highest T /NT ratio was 2.62 ± 0.88 after 5 h from the radiotracer injection. According to previous studies, the radiopharmaceutical had a high uptake both in the infected and inflamed thigh muscle, indicating that 99m Tc-DOX cannot differentiate bacterial infection from sterile inflammation [111]. …”

“…Roohi [110]Direct labelling—SnCl 2 ·2H 2 O3.62 × 10 4 98 % at 6 h96.4 % at 24 hRatLiver (++), kidneys (+) 99m Tc-doxycycline hyclate (DOX)D. Ilem-Ozdemir [111]Stannous tartrate-ascorbic acid3.70 × 10 5 90 % at 6 h94 % at 24 hRatKidneys (++) 99m Tc-erythromycinI. Y. Abdel-Ghaney [112]Direct labelling—SnCl 2 ·2H 2 O1.94 × 10 5 97 % at 2 h87 % at 24 hMouseLiver (+), kidneys (++) 99m Tc-clarithromycinE.…”