PT  - JOURNAL ARTICLE
AU  - Amidon, G. L.
AU  - Taylor, J.
AU  - Sorkness, R.
TI  - A Convective Diffusion Model for Estimating Drug Loss to Tubing: Sorption of Vitamin A
DP  - 1981 Jan 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 13--17
VI  - 35
IP  - 1
4099  - http://journal.pda.org/content/35/1/13.short
4100  - http://journal.pda.org/content/35/1/13.full
SO  - PDA J Pharm Sci Technol1981 Jan 01; 35
AB  - A recently developed convective diffusion model for solute transport in an absorbing tube is applied to the problem of drug loss to tubing under clinical perfusion conditions. The model accounts for the solution flow rate, tubing length, and radius dependence of the drug loss. Vitamin A was used as the test drug. The results of these studies indicate that: (a) the tubing has a high capacity for absorption of vitamin A, but the equilibration of concentration (diffusion) with the tubing wall is relatively slow, (b) with use of an effective wall permeability, the model accounts reasonably well for the solution flow rate and tubing length dependence of the sorption phenomena, (c) the model estimates the amount of vitamin A lost to the tubing under clinical conditions, and (d) the amount of vitamin A lost to the tubing wall from the Total Parenteral Nutrition (TPN) with multivitamin solution is less than that from TPN solution alone, presumably due to the presence of surfactants in the multivitamin preparation.