Lumefantrine solid dispersions with piperine for the enhancement of solubility, bioavailability and anti-parasite activity.

Crystallinity and P-glycoprotein (P-gp) mediated efflux of drugs with low aqueous solubility collaboratively contributes to erratic absorption resulting in low/variable bioavailability. Herein, the amorphous solid dispersions (SD) of lumefantrine (LUMF) containing piperine (PIP), a P-gp and CYP3A4 inhibitor, were formulated with Soluplus (Sol), Klucel (Klu) and Lutrol F68 (Lut), polymeric carriers, to improve solubility and bioavailability of LUMF following oral administration. The LUMF-PIP-SD prepared with Sol exhibited higher aqueous solubility of LUMF in concentration dependent manner and LUMF-PIP-Sol demonstrating maximum aqueous LUMF solubility were characterized by DSC, FTIR and XRD. The DSC thermogram and XRD diffractogram of LUMF-PIP-SD confirmed the loss of crystallinity of LUMF ensuing improved dissolution while possible interaction of LUMF with PIP and /or Sol was evident in FTIR spectrum. DSC and dissolution studies confirmed the stability for LUMF-PIP-Sol SD stored for 90 days under stressed conditions of humidity and temperature. An in situ single-pass intestinal perfusion study in rats indicated 2.2-fold increase in intestinal permeation of LUMF co-administered with PIP. Improved bioavailability of LUMF was evidenced by increased AUC0-∞ and Cmax for LUMF in SD compared to alone LUMF or LUMF with PIP. Peter's four-day suppressive test indicated improved antimalarial activity for LUMF-PIP-Sol SD. Overall, the data suggest that the SD of LUMF incorporated with P-gp inhibitor PIP, improves the bioavailability as well as antimalarial efficacy of LUMF.

Zinc cross-linked hydroxamated alginates for pulsed drug release.

INTRODUCTION: Alginates can be tailored chemically to improve solubility, physicochemical, and biological properties and its complexation with metal ion is useful for controlling the drug release. MATERIALS AND METHODS: Synthesized N,O-dimethyl, N-methyl, or N-Benzyl hydroxylamine derivatives of sodium alginate were subsequently complexed with zinc to form beads. Hydroxamation of sodium alginate was confirmed by Fourier transform infra-red spectroscopy (FTIR) and differential scanning calorimetry (DSC). RESULTS: The synthesized polymeric material exhibited reduced aqueous, HCl and NaOH solubility. The hydroxamated derivatives demonstrated pulsed release where change in pH of the dissolution medium stimulated the atenolol release. CONCLUSION: Atenolol loaded Zn cross-linked polymeric beads demonstrated the sustained the plasma drug levels with increased half-life. Although the synthesized derivatives greatly altered the aqueous solubility of sodium alginate, no significant differences in in vitro and in vivo atenolol release behavior amongst the N,O-dimethyl, N-methyl, or N-Benzyl hydroxylamine derivatives of sodium alginate were observed.