In vitro permeation of tetramethylpyrazine across porcine buccal mucosa.
Abstract
AIM: To examine the in-vitro transport route of tetramethylpyrazine (TMP) across
porcine buccal mucosa and to investigate the effects of drug concentration, pH in
donor chamber, and 1-octanol/buffer partition coefficient on transbuccal
permeation.
METHODS: In-vitro permeation of TMP through porcine buccal mucosa was studied by
using in-line flow through diffusion cells at 37 . The permeability of TMP was
evaluated at different donor pH and drug concentration. Permeability of unionized
(Pu) and ionized TMP (Pi) was calculated by using the Scientist software.
RESULTS: The steady state flux of TMP increased linearly with the donor
concentration (r2=0.96) at pH 7.4. The permeability and the partition coefficient
increased with pH. Pu and Pi were 9.05 x 10(-6) cm.s(-1) and 2.99 x 10(-7)
cm.s(-1), respectively. The total permeability coefficient increased with the
fraction of unionized form.
CONCLUSION: TMP permeated through buccal mucosa by a passive diffusion process.
The partition coefficient and pH dependency of drug permeability indicated that
the drug was transported mainly via the transcellular route by a partition
mechanism.
Keywords:
porcine buccal mucosa and to investigate the effects of drug concentration, pH in
donor chamber, and 1-octanol/buffer partition coefficient on transbuccal
permeation.
METHODS: In-vitro permeation of TMP through porcine buccal mucosa was studied by
using in-line flow through diffusion cells at 37 . The permeability of TMP was
evaluated at different donor pH and drug concentration. Permeability of unionized
(Pu) and ionized TMP (Pi) was calculated by using the Scientist software.
RESULTS: The steady state flux of TMP increased linearly with the donor
concentration (r2=0.96) at pH 7.4. The permeability and the partition coefficient
increased with pH. Pu and Pi were 9.05 x 10(-6) cm.s(-1) and 2.99 x 10(-7)
cm.s(-1), respectively. The total permeability coefficient increased with the
fraction of unionized form.
CONCLUSION: TMP permeated through buccal mucosa by a passive diffusion process.
The partition coefficient and pH dependency of drug permeability indicated that
the drug was transported mainly via the transcellular route by a partition
mechanism.