Levodopa-carbidopa intestinal gel high concentration formulation is clinically bioequivalent to commercial formulation.

A new levodopa-carbidopa intestinal gel (LCIG) system featuring a higher levodopa/carbidopa (LD/CD) concentration and viscosity, LCIG-HV, is being developed to reduce the intrajejunal volume of LD/CD that is administered as compared to the current commercial formulation, LCIG-LV. This study characterizes the LCIG-HV formulation and compares it to the LCIG-LV formulation via dissolution testing and a clinical pharmacokinetic bioequivalence study. In vitro release profiles of LD/CD were determined using a USP Dissolution Apparatus 2 with 500 mL of phosphate buffer (pH 4.5) operating at 25 RPM. A single dose, open-label study was conducted according to a two-period, randomized, crossover design in 28 healthy subjects. The point estimate (PE) of the levodopa Cmax geometric mean for the LCIG-HV formulation was 4% higher than that of the LCIG-LV formulation. PEs of levodopa AUCt and AUCinf geometric means were comparable for both formulations. PEs of carbidopa Cmax , AUCt and AUCinf geometric means for the LCIG-HV formulation were 3%-5% higher than those of the LCIG-LV formulation. For both formulations, the median Tmax for levodopa was 1.0 and 3.0 hours for carbidopa. The levodopa half-life harmonic mean was 1.6 hour for both formulations. The carbidopa half-life harmonic mean was 1.9 and 2.0 hour, respectively, for the LCIG-HV and LCIG-LV formulations. Cmax , AUCt and AUCinf of LD/CD carbidopa were comparable for both formulations. The current study demonstrates that the LCIG-LV and LCIG-HV formulations are clinically bioequivalent for LD/CD according to FDA guidance. However, the dissolution method was over discriminatory of formulation differences.

A Phase 1 Study to Evaluate the Effect of Crushing, Cutting Into Half, or Grinding of Glecaprevir/Pibrentasvir Tablets on Exposures in Healthy Subjects.

Glecaprevir (GLE) and pibrentasvir (PIB) are direct-acting antivirals coformulated as a combination tablet for once-daily treatment of chronic hepatitis C virus infection. The objective of this study was to evaluate the effect of different methods of tablet manipulations-cutting in half, grinding into powder, or crushing-on the bioavailability of GLE and PIB relative to whole film-coated bilayer tablets. This was a phase 1, single-dose, open-label, randomized, 5-period, nonfasting crossover study in 25 healthy adult male and female subjects. Intensive pharmacokinetic measurements were carried out up to 48 h after dosing on day 1 of each period. Safety and tolerability was assessed throughout the study. Compared with the reference whole tablets, cutting into half had minimal impact on GLE and PIB exposures (≤15% difference), whereas grinding or crushing the tablets resulted in lower exposures (27% to 61%) for GLE and higher exposures (21% to 83%) for PIB. These results provide guidance on appropriate administration of GLE/PIB in patients who have difficulty swallowing whole tablets.

Evaluation of the Pharmacokinetic Interaction between Venetoclax, a Selective BCL-2 Inhibitor, and Warfarin in Healthy Volunteers.

BACKGROUND AND OBJECTIVE: Venetoclax is a selective, B-cell lymphoma-2 inhibitor that has demonstrated clinical efficacy in a variety of hematological malignancies. In vitro data indicated weak cytochrome P450 (CYP) 2C9 inhibition by venetoclax; however, it is not predicted to cause clinically relevant inhibition due to high plasma protein binding. A Phase 1 study was conducted in healthy volunteers to evaluate the effect of venetoclax on warfarin pharmacokinetics. METHODS: Subjects received a single oral dose of 5 mg warfarin on day 1 of both periods 1 and 2, separated by a 14 days washout. On day 1 of period 2, subjects concomitantly received a single 400 mg oral dose of venetoclax. Blood samples for warfarin concentration determination were collected after each dose administration for up to 9 days. RESULTS: Modest increases of 18 to 28% were observed in the maximum observed plasma concentration (C max) and area under the curve from time zero to infinity (AUC∞) of both R- and S-warfarin. CONCLUSIONS: Due to the narrow therapeutic window of warfarin, it is recommended that the international normalized ratio (INR) be monitored closely in patients receiving venetoclax and warfarin. Since similar increases in exposure were observed for both enantiomers, even though CYP2C9 is only involved in the metabolism of the S-enantiomer, and the half-life of both enantiomers remained the same, the interaction does not appear to be mediated via CYP2C9.