Absorption of Atropine From Muscle

Abstract

Rates of absorption of atropine after intramuscular injection have been studied by measuring colorimetrically the residual drug in guinea pig muscle. Effects of volume and concentration of the injected solution and the presence of hyaluronidase and polyvinylpyrrolidone on the absorption rates were investigated. Results indicate that, within the range of volumes and concentrations used, for a constant amount of atropine the smaller the volume of injected solution the faster the drug cleared the muscle; solutions of similar volume showed initially faster absorption when a lower concentration of drug was present. Addition of hyaluronidase produced an immediate increase in the clearance rate: four times as much atropine cleared the muscle in the first 35 seconds compared to an untreated solution. Addition of polyvinylpyrrolidone had no appreciable effect.

The Determination of Absorption Rates from Rat Muscles: an Experimental Approach to Kinetic Descriptions

“…This has previously been demonstrated for the strong electrolyte sodium chloride (WARNER et a/. 1953) and for the alkaloid atropine (SCHRIFTMAN & KONDRITZER 1957). Our experiments with the neutral, pharmacologically inert sugars mannitol and sucrose thus show that the phenomenon is general.…”

Netilmicin and Gentamicin: Comparative Pharmacology in Humans

“…injection generally follow a concentration gradient in diffusion from the i.m. site, at least one drug in clinical use does not: atropine has been reported to be more rapidly absorbed when given in a dilute solution and a larger volume (29).…”

Factors Influencing the Use and Interpretation of Animal Models in the Development of Parenteral Drug Delivery Systems

“…This point was demonstrated by the changes in parenteral drug absorption occurring when the integrity of the interstitial network was altered through the addition of hyaluronidase, which degrades hyaluronic acid (HA), also known as hyaluronan. Hyaluronidase-induced degradation of HA at the IM injection site resulted in a marked increase in the rate of atropine rate of absorption in guinea pigs (10). Similarly, hyaluronidase significantly enhanced the absorption of IM administered [ 14 C]inulin but had little influence on the absorption of [ 3 H] water in the gastrocnemius muscle of rabbits (11).…”