ABSTRACT
Repaglinide (RPG) belongs to the class of drugs known as meglitinides and is used for improving and maintaining glycemic control in the treatment of patients with Type 2 diabetes. RPG is a Class II drug (BCS) because of its high permeability and low water solubility. It also undergoes hepatic first-pass metabolism. The oral bioavailability of RPG is low (about 56 %) due to these drawbacks. Our aim in this study is to prepare two different nano-sized drug carrier systems containing RPG (nanoparticle: RPG-PLGA-Zein-NPs or nanoemulsion: RPG-NE) and to carry out a pharmacokinetic study for these formulations. We prepared NPs using PLGA and Zein. In addition, a single NE formulation was developed using Tween 80 and Pluronic F68 as surfactants and Labrasol as co-surfactant. The droplet size values of the blank-NE and RPG-NE formulations were found to be less than 120 nm. The mean particle sizes of blank-Zein-PLGA-NPs and RPG-Zein-PLGA-NPs were less than 260 nm. The Cmax and tmax values of RPG-Zein-PLGA-NPs and RPG-NE (523 ± 65 ng/mL and 770 ± 91 ng/mL; 1.41 ± 0.46 h and 1.61 ± 0.37 h, respectively) were meaningfully higher than those of free RPG (280 ± 33 ng/mL; 0.72 ± 0.28 h) (p < 0.05). The AUC0-∞ values calculated for RPG-Zein-PLGA-NPs and RPG-NE were approximately 4.04 and 5.05 times higher than that calculated for free RPG. These nanosized drug delivery systems were useful in increasing the oral bioavailability of RPG. Moreover, the NE formulation was more effective than the NP formulation in improving the oral bioavailability of RPG (p < 0.05).
ABSTRACT
OBJECTIVE: There is limited information on favipiravir pharmacokinetics in critically ill patients and no studies on pharmacokinetics in patients with moderate and severe kidney dysfunction. The aim was to determine favipiravir pharmacokinetics (oral, 1,600 mg, q12h on day 1, then 600 mg, q12h for 4 days) in critically ill COVID-19 patients with kidney dysfunction and to compare those with observations reported in healthy adults. MATERIALS AND METHODS: In a descriptive study, blood samples taken from patients meeting the relevant criteria (estimated glomerular filtration rate < 60 mL/min) were collected and analyzed. Analysis of blood samples was done by high performance liquid chromatography (HPLC), and the maximal concentration (Cmax), the time of maximal concentration (tmax), half-life (T1/2) and area under the curve (AUC0-12h) of favipiravir were calculated (WinNonlin) and compared to reported data in healthy subjects after first administration. RESULTS: Based on analysis of samples collected in 7 patients, the Cmax (29.99 vs. 64.5 µg/mL) of favipiravir was decreased, T1/2 (5.8 vs. 4.8 hours) longer, tmax delayed, while total exposure was lower (AUC0-12: 192.53 vs. 446.09 µg/mL) compared to reported data in healthy subjects after first administration. Exposure remained lower up to day 5. CONCLUSION: In patients with kidney dysfunction related to COVID-19, favipiravir did not reach the expected exposure. This may be due to poorer and delayed absorption, and subsequent altered disposition. Population pharmacokinetic and mechanistic studies are needed to better explore the relevant covariates and to determine the optimal dose in these patients, as this drug is likely of relevance for other indications.
ABSTRACT
BACKGROUND AND OBJECTIVES: Daidzein has several biological effects such as antioxidation, anti-inflammation, chemoprevention, and anticancer effects. The aim of this study was to evaluate the impact of nano-formulations (nanoemulsion-NE and nanosuspension-NS) prepared to increase the oral bioavailability of daidzein, a poorly water-soluble isoflavone, on the pharmacokinetic parameters of daidzein in rats. METHODS: A high-performance liquid chromatography-ultraviolet (HPLC-UV) method was successfully developed for daidzein analysis in rat plasma. The pharmacokinetics studies of the nano-sized formulations, compared to coarse daidzein suspension, were carried out in the rats by a single oral dose at 10 mg/kg (n = 6/group). Area under the plasma concentration-time curve from time zero to extrapolation to time infinity (AUC0-∞), maximum plasma concentration (Cmax), time to reach maximum plasma concentration (tmax), and elimination half life (t1/2) values for coarse daidzein suspension, daidzein-NS, and daidzein-NE were estimated by a non-compartmental analysis. RESULTS: The AUC values of daidzein-NE and daidzein-NS were approximately 2.62 and 2.65 times higher than that of coarse daidzein suspension, respectively (p < 0.05). Relative bioavailability (Frel) (%) values of daidzein following oral administration of nanosuspension or nanoemulsion formulations were about 265.6% and 262.3%, respectively. CONCLUSION: It revealed that nanoscale size is an important factor to overcome any dissolution rate barriers to oral bioavailability of the low water-soluble compound. Nanoemulsion and nanosuspension formulations are beneficial dosage forms to increase the oral bioavailability of Biopharmaceutical Classification System (BCS) Class II and Class IV compounds.
Subject(s)
Isoflavones , Administration, Oral , Animals , Area Under Curve , Biological Availability , Drug Compounding/methods , RatsABSTRACT
In this study, the release characteristics of gliclazide in a polymeric matrix system, which is used for controlled drug release purposes, are conducted experimentally and numerically. A code using the finite element method predicting the drug release behavior of gliclazide matrix system in an aqueous medium is developed. The parameters having significant importance in drug release kinetics, such as structure factor, the slab's size and shape are varied systematically. The consistent reduction in the solid drug during the dissolution process is evaluated. The numerical data agree well with the experimental results. Therefore, the controlled drug release of gliclazide is accurately modeled by the present numerical code. The results imply that the porosity of the matrix system has the most significant effect on the drug dissolution rate. The reduction in the tablet's diameter and utilization of cylindrical slab geometry increases the speed of the drug dissolution in the aqueous medium.
ABSTRACT
A simple and reliable HPLC method was developed and validated for determination of rofecoxib in bovine serum albumin microsphere. The analyses were performed on a C18 column (150 x 4.6 mm, 5 µm particle size) at room temperature with UV detection at 272 nm. The mobile phase was composed of acetonitrile-0.1% o-phosphoric acid solution in water (1:1, v/v) mixture, and flow rate was set to 1 mL/min. The method was validated according to the international guidelines with respect to stability, linearity range, limit of quantitation and detection, precision, accuracy, specificity, and robustness. The detection and quantification limit of the method were 1.0 µg/mL and 2.5 µg/mL, respectively. The method was linear in the range of 2.5-25 µg/mL with excellent determination coefficients (R2 >0.99). Intra-day and inter-day precision (<1.76% RSD) and accuracy (<0.55 % Bias) values of the method also fulfilled the required limits. It was concluded that the developed method was accurate, sensitive, precise, and reproducible according to the evaluation of the validation parameters. The applicability of the method was confirmed for in vitro quantification of rofecoxib in bovine serum albumin microspheres.
