2015 年 41 巻 5 号 p. 311-320
The lack of commercially available oral dosage forms is an ongoing problem in drug treatment for pediatric patients. To adjust the dose and protect medical staff from drug exposure, an oral liquid dosage form can be prepared. However, information about its long-term stability and appropriate method for daily drug dispensing are limited.
Valganciclovir for cytomegalovirus infections (including pre-emptive therapy) is treated for a long period. The present study investigated the stability of a valganciclovir oral liquid suspension and the development of a simple dispensing method. Triplicate suspensions of valganciclovir 30 mg/mL (as the hydrochloride salt) were prepared from commercially available tablets in reverse osmosis water. The suspensions were subjected to stability testing at room temperature or 2 - 8℃ for up to 14 days. The valganciclovir content of the tablet suspensions decreased during the storage period. Ganciclovir and L-valine, the degradation products formed from the hydrolysis of valganciclovir, were observed immediately after suspension. In acidic solutions prepared using dilute hydrochloric acid solution, the contents of valganciclovir decreased depending on the pH values. Less than 10% degradation occurred in pH 1.8 and 2.8 for 14 days.
To make it easier for pediatric patients to take the drug, suspensions using a mixture of simple syrup and dilute hydrochloric acid solution (pH 2.8) or a mixture of simple syrup and citric acid hydrate (pH 2.8) were prepared. These suspensions were also stable for 14 days at 2 - 8℃. These formulations offer the benefit of a simple compounding procedure with a product that is already available in most pharmacies.