Stability of extemporaneous erlotinib, lapatinib, and imatinib oral suspensions.

Purpose: The stability of extemporaneously prepared erlotinib, lapatinib, and imatinib oral liquid dosage forms using two commercially available vehicles when stored at 4 and 25 °C was evaluated.

Methods: Three batches of extemporaneous oral suspensions were prepared for each drug. Erlotinib and lapatinib tablets were crushed and mixed in a 1:1 mixture of Ora-Plus:Ora-Sweet solution to yield 10- and 50-mg/mL suspensions, respectively. Imatinib tablets were crushed and mixed in Ora-Sweet solution to yield a 40-mg/mL suspension. Suspensions were stored in amber plastic bottles, and samples from each bottle were obtained on days 0, 1, 3, 7, 14, and 28.

Results: Erlotinib 10-mg/mL and lapatinib 50-mg/mL oral suspensions in a 1:1 mixture of Ora-Plus and Ora-Sweet retained at least 90% of their initial concentration throughout the 28-day study when stored at 25 °C. Visual inspection revealed notable viscosity changes in the erlotinib and lapatinib suspensions stored at 4 °C for 7 days and beyond. The viscosity of these preparations increased with time and was particularly evident with the erlotinib suspension, which exhibited a puddinglike texture. Imatinib 40-mg/mL oral suspension in Ora-Sweet appeared stable for up to 14 days when stored at both 25 and 4 °C.

Conclusion: Erlotinib 10-mg/mL and lapatinib 50-mg/mL oral suspensions prepared from commercially available tablets were stable for at least 28 days when prepared in a 1:1 mixture of Ora-Plus:Ora-Sweet at 25 °C. Imatinib 40-mg/mL oral suspension prepared from commercially available tablets was stable for up to 14 days when prepared in Ora-Sweet and stored at 25 and 4 °C.