Intravenous delivery of furosemide using lipid-based versus polymer-based nanocapsules: in vitro and in vivo studies.

OBJECTIVES: Furosemide (FSM), a potent loop diuretic, is used to treat edema due to hypertension, congestive heart failure, and liver and renal failures. FSM applications are limited by its low bioavailability. Our aim is to use different nanoencapsulation strategies to control the release of FSM and enhance its pharmacokinetic properties. METHODS: Two types of FSM-loaded nanocapsules, namely FSM-loaded lipid nanocapsules (LNCs) and polymeric nanocapsules (PNCs), were developed, physicochemically characterized, and subjected to pharmacokinetic and pharmacodynamic studies. Lipid nanocapsules were prepared by the simple phase inversion method using LabrafacTM lipid, while the polymeric nanocapsules were prepared by nanoprecipitation method using polycaprolactone polymer. RESULTS: Transmission electron microscopy ascertains spherical structures, corroborating the nanometric diameter of both types of nanocapsules. The particle size of the optimized FSM-loaded LNCs and FSM-loaded PNCs was 32.19 ± 0.72 nm and 230.7 ± 5.13 nm, respectively. The percent entrapment efficiency was 63.56 ± 1.40% of FSM for the optimized PNCs. The in vitro release study indicated prolonged drug release compared to drug solutions. The two loaded nanocapsules systems succeeded in enhancing the pharmacokinetic parameters in comparison to the marketed FSM solution with superior diuretic activity (p < 0.05). The results of the stability study and the terminal sterilization by autoclave indicated the superiority of LNCs over PNCs in maintaining the physical parameters under storage conditions and the drastic conditions of sterilization. CONCLUSIONS: LNCs and PNCs are considered promising nanosysems for improving the diuretic effect of FSM.

The impact of folate pathway variants on the outcome of methotrexate therapy in rheumatoid arthritis patients.

BACKGROUND: There are currently no validated criteria that entirely explain or predict response to methotrexate (MTX) treatment in rheumatoid arthritis (RA). We tried to identify the connection between three variants (RFC1 G80A (rs1051266), TYMS 2R/3R (rs34743033), and ATIC C347G (rs2372536)) in the folate pathway of MTX metabolism and the response to MTX monotherapy in a cohort of RA cases. METHODS: A prospective study on 100 RA patients on MTX monotherapy was performed. Disease activity was measured at the start of treatment and 6 months after treatment with MTX. The patients were then split into two groups: those who responded to the treatment and those who did not. The molecular genetic study for the RFC1 (G80A) variant was employed via the PCR-restriction fragment length polymorphism (PCR-RFLP) technique, the ATIC (C347G) variant was performed using TaqMan allelic discrimination real-time PCR, and the tandem repeat sequences of TYMS (2R/3R) were amplified by conventional PCR and detected by agarose gel electrophoresis. RESULTS: The genotype distribution of RFC-1 (G80A) showed significant variations among non-responders and responders in the recessive genetic model. A significant difference was found in TYMS (2R/3R) in the dominant and heterozygous genetic models. However, ATIC (C347G) genotype frequency did not exhibit substantial link with drug response in all genetic models. Furthermore, the genotype and allele rates of the analyzed variants did not show any significant association with adverse events in all genetic models. CONCLUSION: The 80AA genotype of RFC-1 G80A and the 2R/3R or 3R/3R genotypes of TYMS 2R/3R are more vulnerable to the good consequences of MTX therapy. Key Points • Current recommendations support the gold standard role of MTX as a first-line monotherapy for RA patients. However, up to 40% of RA patients do not respond or exhibit partial response to MTX. • Persistent disease activity due to treatment unresponsiveness will affect the long-term outcomes in RA patients. • We aimed, through molecular genetic study, to identify the connection between three variants in the folate pathway of MTX metabolism and the response to methotrexate monotherapy in a cohort of RA patients.