Tolerance and pharmacokinetics of single-dose intravenous hemoporfin in healthy volunteers.

AIM: To investigate the safety, tolerability and pharmacokinetics of intravenous hemoporfin, a novel photosensitive drug for the treatment of port-wine stain (PWS), in healthy Chinese volunteers following single-dose administration. METHODS: Thirty-six healthy Chinese subjects were enrolled. The subjects were administered hemoporfin (2.5, 5, 7.5 or 10 mg/kg) via single-dose intravenous infusion. Pharmacokinetics of the drug were studied in the groups with doses of 2.5, 5 and 7.5 mg/kg, and tolerability was studied in all the 4 groups. Safety and tolerance were evaluated by monitoring adverse events and laboratory parameters, and pharmacokinetics were assessed by determining hemoporfin content with a validated high-performance liquid chromatography with fluorescence detection (HPLC/FLD) method. RESULTS: Mild and transient adverse events occurred in the trial (n=10), but none were serious, and no subjects were withdrawn from the trial. The gastrointestinal tract adverse events, such as nausea, stomach upset, abdominal pain and vomiting, were observed in the groups with doses of 7.5 and 10 mg/kg. Increased alanine aminotransferase (ALT) concentration was found in 3 subjects, and increased alkaline phosphatase (ALP) concentration in one subject. The half-life of hemoporfin for doses of 2.5, 5, and 7.5 mg/kg was 1.26 h, 1.31 h, and 1.70 h, respectively. C(max) and AUC increased with dose for intravenous single-dose administration of hemoporfin in the 2.5, 5, and 7.5 mg/kg groups. Urinary excretion of hemoporfin within 12 h was less than 0.2%. CONCLUSION: Hemoporfin is safe and well-tolerated in healthy Chinese volunteers at a single intravenous dose of up to 10 mg/kg. It was rapidly cleared from the blood and had a short half-life, which insures a short light-avoidance period.

[Experimental studies on treatment of HSV infections with photodynamic therapy using 5-aminolevulinic acid].

OBJECTIVE: To investigate in vitro and in vivo anti-human herpes simplex virus effects of photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA). METHODS: Guinea pigs model of cutaneous herpes virus infection was applied, and Vero cells infected by HSV-I and HSV-II were used as experimental systems to observe the antiherpes effect of ALA-PDT. RESULTS: The in vitro experiments showed that ALA-PDT has antiherpes effect on HSV-I and HSV-II, its effect was similar to that of acyclovir. The results of animal experiments showed that ALA-PDT had significant therapeutic effect on guinea pigs model of cutaneous herpes virus infection, the effect was dose-related. CONCLUSION: ALA-PDT could be effective in treating HSV infections, which may provide a new approach to the treatment of viral infections.

Development and validation of a sensitive quantification method for hematoporphyrin monomethyl ether in plasma using high-performance liquid chromatography with fluorescence detection.

A rapid, sensitive, precise and specific method for determination of hematoporphyrin monomethyl ether (HMME), a novel photodynamic therapy (PDT) drug, was developed and validated using high-performance liquid chromatography (HPLC) with fluorescence detection. HMME was isolated from the plasma by a single-step liquid-liquid extraction with ethyl acetate. The analyte and internal standard fluorescein were baseline separated on a Diamonsil C(18) analytical column (4.6 x 150 mm, 5 microm) and analyzed using a fluorescence detector with the excitation and emission wavelengths set at 395 and 613 nm, respectively. The method was linear in the concentration range 0.025-5 microg/mL with a lower limit of quantitation (LLOQ) of 10 ng/mL. The inter- and intra-day accuracies and precisions were all within 10% and the mean recoveries of HMME and fluorescein were 95 +/- 3.7 and 90 +/- 2.3%, respectively. The analyte was stable during all sample storage, preparation and analysis periods. This method was successfully applied to a pharmacokinetic study after a single-dose intravenous administration of HMME (5 mg/kg) to beagle dogs. This method was reproducible and sensitive enough for the pharmacokinetic study of HMME. Based on the results of the pharmacokinetic study, we suggest that a rather long light-avoiding time is essential for patients under HMME therapy.