Quality of intrathecal baclofen from different sources

To compare the quality of intrathecal baclofen obtained from a national compounding pharmacy (AnazaoHealth) with the manufactured product (Lioresal) with regard to accuracy and precision of baclofen concentration, and the content of the baclofen degradation product, 4-(4-chlorophenyl)-2-pyrrolidinone (PYR).

Samples of baclofen used for refilling intrathecal pumps were placed in 1.2-mL silicone gasket-sealed cryogenic vials and stored at or lower than -25°C. Each sample was a different lot number (Lioresal) or prescription number (AnazaoHealth). The laboratory was blinded to the source of the solutions. Coupled with electrospray ionization-mass spectrometry analyte confirmation, quantitation of baclofen and PYR in each sample was performed in duplicate by using high-performance liquid chromatography with ultraviolet detection via a photodiode array detector.

Outpatient clinic.

Patients with intrathecal baclofen pumps.

Accuracy and precision of baclofen concentration, and concentration of PYR.

The difference of mean concentrations from expected concentrations of 500 and 2000 μg/mL were significantly greater for samples from AnazaoHealth compared with Lioresal. Values are shown as mean (± standard error), with n the number samples, for AnazaoHealth compared with Lioresal: (537.1 ± 6.7 μg/mL [n = 8] versus 515.6 ± 0.82 μg/mL [n = 5]; P = .034, respectively) and (2211.4 ± 21.6 μg/mL [n = 12] versus 2055.3 ± 8.7 μg/mL [n = 4]; P = .004, respectively). AnazaoHealth samples with expected concentration of 4000 μg/mL were 3987.7 ± 79.9 μg/mL, n = 7. All 9 Lioresal samples were within 5% of the expected concentration. Of 27 AnazaoHealth samples, 22 were more than 5%, and 8 were more than 10% different from the expected concentration. No PYR was detected in any sample from AnazaoHealth. All samples of Lioresal contained PYR, but all solutions contained less PYR than 1% of the baclofen concentration.

Lioresal was more accurate in concentration and more precise among batches than compounded intrathecal baclofen but had higher levels of PYR.