Pharmacokinetics of Sirolimus Eye Drops Following Topical Ocular Administration in Rabbits.

Purpose: To evaluate the pharmacokinetics of sirolimus eye drops following topical instillation in rabbits. Methods: The study included 2 experiments. In single-dose pharmacokinetic study, rabbits received a single bilateral instillation of 0.05% sirolimus eye drops (0.5 mg/mL, 50 µL/eye). In repeat-dose pharmacokinetic study, 0.05% sirolimus eye drops (0.5 mg/mL, 50 µL/eye/time) were instilled into both eyes of rabbits four times a day for 6 consecutive days and one time on day 7. Whole blood, tears, aqueous humor, cornea, and conjunctiva samples were collected. Sirolimus concentration was determined by a validated liquid chromatography-tandem mass spectrometry. Results: Sirolimus was hardly detected in plasma or aqueous humor after either single or repeated dosing. The Cmax of sirolimus in tears, cornea, and conjunctiva after a single instillation was 163.34 ± 69.30 µg/g, 150.56 ± 84.98 ng/g, and 113.22 ± 49.82 ng/g, respectively. As the number of instillation elevated, the Cmax of sirolimus was increased to 486.18 ± 297.93 µg/g, 418.63 ± 41.07 ng/g, and 314.25 ± 63.74 ng/g, respectively. In repeat-dose administration, the steady state of sirolimus concentration was achieved on the third day. Ocular exposure to sirolimus after single and repeated dosing, based on AUC0-t, was highest in tears, followed by cornea and conjunctiva. Compared with single administration, a significant increase in sirolimus exposure as measured by AUC0-t was observed in tears, cornea, and conjunctiva following repeated administration. Conclusions: Topical administration of sirolimus eye drops results in extensive distribution of sirolimus in tears, cornea, and conjunctiva, while aqueous humor and systemic exposure were negligible. Repeat-dose administration increases sirolimus exposure in tears, cornea, and conjunctiva.

Immunization with a Prefusion SARS-CoV-2 Spike Protein Vaccine (RBMRNA-176) Protects against Viral Challenge in Mice and Nonhuman Primates.

There is an urgent need for a broad-spectrum and protective vaccine due to the emergence and rapid spreading of more contagious SARS-CoV-2 strains. We report the development of RBMRNA-176, a pseudouridine (Ψ) nucleoside-modified mRNA-LNP vaccine encoding pre-fusion stabilized trimeric SARS-CoV-2 spike protein ectodomain, and evaluate its immunogenicity and protection against virus challenge in mice and nonhuman primates. A prime-boost immunization with RBMRNA-176 at intervals of 21 days resulted in high IgG titers (over 1:819,000 endpoint dilution) and a CD4+ Th1-biased immune response in mice. RBMRNA-176 vaccination induced pseudovirus-neutralizing antibodies with IC50 ranging from 1:1020 to 1:2894 against SARS-CoV-2 spike pseudotyped wild-type and variant viruses, including Alpha, Beta, Gamma, and Kappa. Moreover, significant control of viral replication and histopathology in lungs was observed in vaccinated mice. In nonhuman primates, a boost given by RBMRNA-176 on day 21 after the prime induced a persistent and sustained IgG response. RBMRNA-176 vaccination also protected macaques against upper and lower respiratory tract infection, as well as lung injury. Altogether, these findings support RBMRNA-176 as a vaccine candidate for prevention of COVID-19.

Genetic Toxicology and Safety Pharmacological Evaluation of Forsythin.

INTRODUCTION: Forsythin is the main ingredient of Forsythia suspensa and is widely used in treatment of fever, viral cold, gonorrhea, and ulcers clinically. This study aimed to evaluate the potential genetic toxicity of forsythin and its safety for human use. METHODS: Based on the Good Laboratory Practice regulations and test guidelines, the genetic toxicity of forsythin was assessed by the Ames test, chromosome aberration (CA) test, and bone marrow micronucleus (MN) test in vivo. In the Ames test, five strains of Salmonella typhimurium were exposed to different concentrations of forsythin in the presence or absence of the S9 mixture, and then, the number of His + revertant colonies was counted. In the CA test, Chinese hamster lung (CHL) fibroblast cells were treated with different concentrations of forsythin, mitomycin C, or cyclophosphamide in the presence or absence of the S9 mixture, and the chromosomal aberrations were determined. In the MN test, bone marrow was isolated from the mice with different treatments, and the ratios of polychromatic erythrocytes (PCE) and erythrocytes (PCE/(PCE + NCE)) were measured. Finally, beagle dogs were divided into four groups (negative control, low dose, medium dose, and high dose groups), and then, a telemetry system was used to evaluate the safe use of forsythin. RESULTS: Ames test results showed that the number of colonies in all test strains with different treatments showed no significantly dose-dependent increase in the presence or absence of the S9 mixture (p > 0.05). In the CA test, the number of cells with aberrations in the CHL fibroblast cells treated with low, medium, and high doses of forsythin for 24/48 h in the absence of the S9 mixture was, respectively, 5.0/2.5, 4.5/1.5, and 5.0/5.0, and in the presence of the S9 mixture, the number was, respectively, 5.0, 5.0, and 4.5. These results showed that there was no significant difference compared to the negative control group either in the presence (2.0) or in the absence (4.0/2.5 for 24/48 h) of the S9 mixture (p > 0.05). The MN test showed that the values of PCE/(PCE + NCE) in the negative, positive controls, and forsythin treatment groups were all more than 20%, which indicated that forsythin had no cytotoxicity. Additionally, no significant toxicological effects of forsythin on blood pressure, respiration, temperature, electrocardiogram, and other physiological indicators in the conscious beagle dogs of different groups were observed by the telemetry method. CONCLUSION: Our findings showed that forsythin has low probability of genetic toxicity and no significant toxicological effects, which implied that forsythin is suitable for further development and potential application.

Reproductive Systemic Toxicity and Mechanism of Glucosides of Tripterygium wilfordii Hook. F. (GTW).

BACKGROUND: To study the mechanism of reproductive systemic toxicity of Tripterygium wilfordii on SD rats. METHODS: The SD rats were randomly divided into groups and allocated three different treatments: control, 37.8 mg/kg Tripterygium glycosides, and 94.5 mg/kg Tripterygium glycosides, with each treatment applied for different lengths of time to 20 animals. Each group received treatment by intragastric administration once per day for 90 days. The estrus cycle was continuously observed throughout treatment. Animals were killed at each time point and analyses of sex hormones, sexual organ weights and coefficients, semen, pathology, and immunohistochemistry were conducted. RESULTS: The metestrus phase of the rats administered the low-dose and high-dose treatments was significantly decreased. The uterus organ-body coefficients of female rats were significantly increased, whereas the testis and epididymis organ-body and organ-brain coefficients in male rats were significantly decreased by the high-dose and low-dose treatments at different time points. An increase in immature sperm and sperm abnormality rate was observed at different times in the low-dose and high-dose groups. Pathological changes were clear in the testis, epididymis, ovary, and uterus. The levels of multiple hormones were significantly decreased. The hypothalamus estrogen receptor alpha (ER-α) receptor expression in female rats was also significantly decreased. The androgen receptor (AR) expression in the hypothalamus and the testis and epididymis was significantly decreased at different times by the high-dose treatment. CONCLUSION: Tripterygium glycosides affected the estrus cycle in female rats and caused damage to the uterus; in male rats, the testicles and sperm were damaged. The mechanism of reproductive toxicity occurred through the secretion of multiple hormones.

Comparative safety assessments of the biosimilar APZ001 and Erbitux in pre-clinical animal models.

PURPOSE: To evaluate the toxicity of Erbitux as well as its biosimilar APZ001 antibody (APZ001) in pre-clinical animal models including mice, rabbits and cynomolgus monkeys. METHODS: We performed analysis of normal behavior activity, autonomic and non-autonomic nervous functions, nervous-muscle functions, nervous excitability and sensorimotor functions on CD-1 mice. Subsequently, we studied that effects of APZ001 and Erbitux on respiratory system, cardiovascular system and kidney in Cynomolgus monkey models and performed local tolerance experiments on New Zealand rabbits. RESULTS: The comparisons between APZ001 and Erbitux showed no significant differences in mice autonomic nervous system, nervous muscle functions, non-autonomic nervous functions, nervous excitability and sensorimotor functions between treated and untreated group (p>0.05). APZ001 and Erbitux showed negative effect on CD-1 mice in the present of pentobarbital sodium anesthesia (p>0.05). Single administrations of high, medium or low doses of APZ001 did not lead to monkey urine volume alterations (p>0.05). In human tissues, APZ001 and Erbitux showed positive signals in endocardium, lung type II alveolar epithelial cell and surrounding vessels, but showed negative results in kidney and liver tissues. No hemolysis phenomenon and serious side-effects in vessels and muscles were observed in rabbits when administrated with APZ001 and Erbitux respectively. CONCLUSION: The safety comparisons between APZ001 antibody and Erbitux showed that these two antibodies showed highly similarities in mice, rabbits and cynomolgus monkey animal models in consideration of pharmaceutical effects, indicating APZ001 might be a suitable substitute for Erbitux.

Comparative safety assessments of the biosimilar APZ001 and Erbitux in pre-clinical animal models

Abstract Purpose: To evaluate the toxicity of Erbitux as well as its biosimilar APZ001 antibody (APZ001) in pre-clinical animal models including mice, rabbits and cynomolgus monkeys. Methods: We performed analysis of normal behavior activity, autonomic and non-autonomic nervous functions, nervous-muscle functions, nervous excitability and sensorimotor functions on CD-1 mice. Subsequently, we studied that effects of APZ001 and Erbitux on respiratory system, cardiovascular system and kidney in Cynomolgus monkey models and performed local tolerance experiments on New Zealand rabbits. Results: The comparisons between APZ001 and Erbitux showed no significant differences in mice autonomic nervous system, nervous muscle functions, non-autonomic nervous functions, nervous excitability and sensorimotor functions between treated and untreated group (p>0.05). APZ001 and Erbitux showed negative effect on CD-1 mice in the present of pentobarbital sodium anesthesia (p>0.05). Single administrations of high, medium or low doses of APZ001 did not lead to monkey urine volume alterations (p>0.05). In human tissues, APZ001 and Erbitux showed positive signals in endocardium, lung type II alveolar epithelial cell and surrounding vessels, but showed negative results in kidney and liver tissues. No hemolysis phenomenon and serious side-effects in vessels and muscles were observed in rabbits when administrated with APZ001 and Erbitux respectively. Conclusion: The safety comparisons between APZ001 antibody and Erbitux showed that these two antibodies showed highly similarities in mice, rabbits and cynomolgus monkey animal models in consideration of pharmaceutical effects, indicating APZ001 might be a suitable substitute for Erbitux.

[Synthesis of beta-cyclodextrin polymer beads and its behavior of drug release].

OBJECTIVE: To prepare beta-cyclodextrin polymer (beta-CDP) beads using as a drug carrier and study the release behaviors of Berberine Hydrochlorrde (BH) in beta-CDP beads. METHODS: beta-CDP beads were synthesized by inverse emulsion polymerization. The inclusion complex between beta-CD and BH were investigated by phase solubility method. And the release of BH in vitro was studied by UV spectra. RESULTS: Inclusion compounds of beta-CD and BH with 1: 1 molar ratio were found under the condition of pH 1.4 and pH 7.4, with corresponding stability constants of 48.85 L/mol and 122.11 L/mol, respectively. Finally, the controlled release behavior of BH in polymer beads were studied and the release rate of BH kept almost constant after 24 h. Release rate of BH was higher at pH 1.4 than that at pH 7.4. CONCLUSION: beta-CDP beads may be an ideal controlled drug release carrier.