The invention relates to an aqueous composition comprising a quaternary ammonium blocking agent and a polyhydroxy acid based excipient, and a method for producing said composition. In particular the neuromuscular blocking agent may be a Rocuronium salt and the excipient is an aldonic acid, e. g. gluconic acid or an intramolecular lactone thereof. Furthermore, the invention relates to a liquid pharmaceutical composition comprising said aqueous composition. The compositions of the present invention can further be comprised in a container made of glass or an organic polymer. Additionally, the invention relates to a pharmaceutical kit comprising the compositions of the present invention.
