Improvement of the Local Tolerance of a Potassium Penicillin G Formulation for Injection

Abstract

The damaging effect at the injection site (muscle) of a series of different preparations of penicillin C with increasing content of citrate buffer has been investigated in rabbits in order to improve the local tolerance of the drug preparation. The injections were given in M.sacrospinal and 3 days after injection the animals were sacrified and the areas of necrotic muscle tissue were isolated and weighed. The damage from the different preparations was determined on the basis of these weighing results. It was concluded that Novocillin 3.15 g and 6.3 g in 20 ml aqueous solution could be improved by adding 3x the original content of citrate buffer to the preparation resulting in a 38% decrease of the mean weight of necrotic areas at the injection site. Moreover, it was shown that the mean weight of necrotic areas at the injection site was diminished by 41% when injecting the improved 6.3 g concentration in a volume of 0.1 ml compared to injecting the improved 3.15 g concentration in a volume of 0.2 ml, which provides the same dose of penicillin G.

Sammanfattning

Den vävnadsirriterande effekten av en serie penicillin G formuleringar innehållande stigande mängder av citrat buffer studerades hos kanin. Infektionerna gavs i M.sacrospinalis. Kaninerna avlivades efter 3 dagar och skadade muskelpartier isolerades och vägdes. Det visades att den lokala toleransen hos Novocillin 3.15 g och 6.3 g kunde förbättras signifikant om innehållet av citrat buffer ökades 300%. Den förbättrade formuleringen resulterade i en 38%-ig reduktion av vävnadsskadorna. Det visades också att 0.1 ml av den förbättrade 6.3 g formuleringen gav 41% mindre vävnadsskador än 0.2 ml av motsvarande 3.15 g formulering.