[Bioavailability of folic acid following intramuscular and intravenous administration to healthy volunteers].
Bioavailability of Folic Acid Following Intramuscular and Intravenous Administration to Healthy Volunteers 2 mg folic acid (Folsan 2, CAS 59-30-3) were either i.m. or i.v. administered as injection solution to 15 male healthy subjects within an open balanced two-way crossover study. The concentration-time profile of folic acid was determined up to 12 h p.a. in serum and urine using a radioassay. Each change-over phase included a 9 days lasting saturation phase with once-per-day oral administration of a tablet containing 5 mg folic acid. Saturation was performed in order to guarantee filled-up endogenous folate storage compartments in the body of the subjects. After a four-day wash-out phase the subjects were confined and the basic serum level and basic renal 0-12 h folate excretion determined. On the following morning the respective dose of 2 mg folic acid was either i.m. or i.v. applied to the subjects (treatment day 14). 11 (i.m.) and 15 (i.v.) venous blood specimens were drawn up to 12 h p.a. and urine collected following the same schedule as the day before in 4 different fractions. The mean predose level of folic acid in serum was 13.2 +/- 4.85 ng/ml before the i.m. administration and 13.3 +/- 5.59 ng/ml before i.v. administration. The serum concentration data following the respective single administrations were corrected by subtraction of the individual predose values. After 0.50 +/- 0.19 h (mean tmax) the folate serum level increased by 101 +/- 27.2 ng/ml after the i.m. dose. Serum concentration decreased in the following 6-8 h approximately to the predose values.(ABSTRACT TRUNCATED AT 250 WORDS)
Menke
G
G
PAZ Arzneimittel-Entwicklungsgesellschaft mbH, Frankfurt/Main.
Müller
J
J
Weimann
H J
HJ
Schuster
O
O
D000328:Adult; D001682:Biological Availability; D005492:Folic Acid / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006207:Half-Life; D006801:Humans; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D008297:Male
D005492:Folic Acid