Dual Formulation and Interaction Strategies to Enhance the Oral Bioavailability of Paclitaxel.

A self-microemulsifying drug delivery system (SMEDDS) was developed to enhance Paclitaxel (PTX) solubility and membrane permeability, thus improve its bioavailability. Pre-formulation studies were performed to optimize PTX-SMEDDS formulation. Then, in vitro characteristics of the formulation were determined and PTX oral absorption was investigated in rabbits.

Comparative Pharmacokinetic Study for Linezolid and Two Novel Antibacterial Oxazolidinone Derivatives in Rabbits: Can Differences in the Pharmacokinetic Properties Explain the Discrepancies between Their In Vivo and In Vitro Antibacterial Activities?

This is a comparative pharmacokinetics study of linezolid (Lzd), and two novel oxazolidinone antibacterial agents-PH027 and PH051-in rabbits to determine if the discrepancy between the in vitro and in vivo activities of the novel compounds is due to pharmacokinetic factors. The pharmacokinetics after IV and oral administration, plasma protein binding and tissue distribution for the three compounds were compared. The elimination half-lives were 52.

A validated UPLC-MS/MS method for the analysis of linezolid and a novel oxazolidinone derivative (PH027) in plasma and its application to tissue distribution study in rabbits.

Objectives: Linezolid is the first approved oxazolidinone antibacterial agent, whereas PH027 is a novel compound of the same class that exhibits good in vitro antibacterial activity. The objective of this study was to develop an UPLC-MS/MS assay for the analysis of linezolid and PH027 in plasma and to apply the method for comparative pharmacokinetic and tissue distribution studies of both compounds.

Method: Plasma samples and calibrators were extracted with diethyl ether after addition of the internal standard solution.

Modeling of the pharmacokinetic/pharmacodynamic interaction between irbesartan and hydrochlorothiazide in normotensive subjects.

Purpose: To investigate the pharmacokinetic/pharmacodynamic (PK/PD) interaction between irbesartan (IRB) and hydrochlorothiazide (HCT) in normotensive subjects.

Methods: A three-way crossover study was used. Serial drug concentrations and drug effects, including systolic and diastolic blood pressure and heart rate were monitored after administration of irbesartan and hydrochlorothiazide alone and in combination.

Pharmacokinetic interactions of valsartan and hydrochlorothiazide: an open-label, randomized, 4-period crossover study in healthy Egyptian male volunteers.

Background: Co-administration of valsartan (VAL) and hydrochlorothiazide (HCT) has been used to regulate blood pressure. Compliance with a multiple medication regimen can be difficult for some patients; therefore, a combination of VAL + HCT tablets may be a suitable alternative.

Objective: This study was conducted to compare the rate and extent of absorption of VAL and HCT after oral administration as a fixed-dose combination (FDC) tablet and concomitant administration of the individual drugs under fasting conditions in healthy Egyptian subjects.

Study of the Urinary Ratio of 6 beta-Hydroxycortisol/Cortisol as a Biomarker of CYP3A4 Activity in Egyptian Patients with Chronic Liver Diseases.

The urinary ratio of 6 beta-hydroxycortisol/cortisol (6 beta-OHC/C) as a biomarker of CYP3A4 metabolizing activity has been studied in Egyptian patients with chronic liver cirrhosis associated with previous hepatic Schistosomiasis infection to determine any possible alteration in enzyme activity. The ratio of 6-beta OHC/C was determined in morning urine samples collected from 8:00 a.m.

The effect of ciprofloxacin and clarithromycin on sildenafil oral bioavailability in human volunteers.

Sildenafil is the first oral therapeutic agent for the management of male erectile dysfunction. Its oral bioavailability is only 40% due to extensive presystemic elimination, mainly by CYP3A4. This study examined the effect of coadministration of ciprofloxacin or clarithromycin, which inhibit CYP3A4, on the bioavailability and pharmacokinetics of sildenafil.

Intestinal absorption and presystemic disposition of sildenafil citrate in the rabbit: evidence for site-dependent absorptive clearance.

Sildenafil citrate is the first oral treatment for erectile dysfunction. Its oral bioavailability is about 40%. This research investigated the intestinal transport parameters of sildenafil citrate in rabbit using an in situ intestinal perfusion technique.

Study of urinary 6 beta-hydroxycortisol/cortisol ratio in spot urine sample as a biomarker of 3A4 enzyme activity in healthy and epileptic subjects of Egyptian population.

The ratio of urinary 6 beta-hydroxycortisol/cortisol (6 beta-OHC/FC) in morning spot urine samples collected from 8:00 a.m. to 12:00 p.