Pharmacokinetics and Pharmacodynamics Evaluation of Tramadol in Thermoreversible Gels

Evaluation of Budesonide-Hydroxypropyl-β-Cyclodextrin Inclusion Complex in Thermoreversible Gels for Ulcerative Colitis

BACKGROUND

New formulations for topical treatment of ulcerative colitis with budesonide inclusion complex (BUD_HP-β-CD) and poloxamers (PL) were developed for future clinical use.

AIMS

This study evaluated the efficacy of such novel formulations in a rat model of colitis.

METHODS

The PL-BUD_HP-β-CD systems were prepared by direct dispersion of the complex (BUD concentration 0.5 mg mL^-1) in solutions with PL407 or PL403. Male Wistar rats underwent TNBS-induced colitis and were treated for 5 days by a rectal route, as follows: BUD 1: BUD_HP-β-CD + PL407 (18%); BUD 2: BUD_HP-β-CD + PL407 (20%); BUD 3: BUD_HP-β-CD + PL407 (18%) + PL403 (2%); BUD 4: plain BUD; BUD 5: BUD_HP-β-CD; C1: HP-β-CD + PL407 (18%); C2: HP-β-CD + PL407 (20%); C3: HP-β-CD + PL407 (18%) + PL403 (2%); C4: saline. A negative control group without colitis was also used. Colitis was assessed via myeloperoxidase (MPO) activity, and macroscopic and microscopic damage score in colon tissues. Protein levels of TNF-α, IL-1β, IL-10 and endogenous glucocorticoids were obtained using ELISA.

RESULTS

BUD_HP-β-CD poloxamer formulations had similar MPO activity when compared with the negative control group. All formulations presented lower MPO activity than BUD_HP-β-CD and plain BUD (p < 0.001). BUD 2 produced lower microscopic score values than plain BUD and BUD_HP-β-CD (p < 0.01). All formulations with BUD_HP-β-CD poloxamers reduced TNF-α levels (p < 0.05).

CONCLUSION

Novel budesonide inclusion complex formulations improved microscopic damage and reduced colonic MPO activity and TNF-α levels.

Bupivacaine in alginate and chitosan nanoparticles: an in vivo evaluation of efficacy, pharmacokinetics, and local toxicity

Objective

This study reports a preclinical evaluation of an alginate/chitosan nanoparticle formulation containing NovaBupi®, a racemic bupivacaine (BVC) containing 25% dextrobupivacaine and 75% levobupivacaine.

Methods

New Zealand White rabbits (n=6) received intraoral or intrathecal injections of BVC 0.5% or BVC 0.5%-loaded alginate–chitosan nanoparticles (BVC_ALG). BVC plasma levels and pharmacokinetic parameters were determined in blood samples of these rabbits. An infraorbital nerve blockade was performed in male Wistar rats (n=7) with the same formulations and the vehicle (NP_ALG). Histological evaluation of local toxicity after 6 hours and 24 hours of the treatments was performed in rats’ (n=6) oral tissues.

Results

No statistically significant difference was observed between plasma concentrations and pharmacokinetic parameters (p>0.05) after intraoral injections. However, after intrathecal injection BVC_ALG changed approximately three times the values of volume of distribution and area under the curve (AUC_0–t; p<0.05). The total analgesic effect of BVC after infraorbital nerve blockade was improved by 1.4-fold (p<0.001) with BVC_ALG. BVC and BVC_ALG did not induce significant local inflammatory reaction.

Conclusion

The encapsulation of BVC prolongs the local anesthetic effect after infraorbital nerve blockade and altered the pharmacokinetics after intrathecal injection.