Related Experiment Video
Updated: Feb 10, 2026

Formulations for Freeze-drying of Bacteria and Their Influence on Cell Survival
Published on: August 3, 2013
Analysis of the Postoperative Periarticular Environment and Influence on Sustained Drug Delivery From a Gel
Darren Svirskis1, Waldron Martis2, Prabhat Bhusal1
1School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1142, New Zealand.
Abstract:
Regional intraarticular delivery of local anesthetics is effective in treating postoperative pain following total knee or hip replacement. Recent research efforts have been only partially successful in achieving sustained release of the analgesic agent, in part due to limited understanding of the biological environment into which these formulations are administered. This study aimed to detail the composition and properties of postoperative periarticular fluid (PO-PAF). PO-PAF was collected from 8 patients, and the composition and physicochemical properties were determined. A number of components were identified which are lacking from phosphate buffered saline (PBS) or other synthetic media. The differences in composition led to variation in the physicochemical properties of PO-PAF compared with PBS. Notably, significantly lower surface tension (p <0.05) and higher buffer capacity (p <0.05) were observed in the biological fluid. We demonstrated that the solubility of lidocaine is almost double in PO-PAF compared to PBS (p <0.05) and that lidocaine release from a poloxamer gelling system occurred faster into PO-PAF under both sink and nonsink conditions. Collectively, these data indicate PBS is inappropriate for the in vitro evaluation of intraarticular drug delivery systems. The presented data describe that PO-PAF and will support the future development of biorelevant media to ultimately improve in vivo-in vitro correlation.
More Related Videos
Related Concept Videos
Sustainable Development
Insulin Formulations: Types and Delivery
Short-acting insulins are divided into...
Factors Influencing Drug Absorption: Drug Dissolution
Drug Delivery: Overview
Enteral delivery involves administering drugs directly through swallowing, sublingual placement, or buccal application. Orally administered drugs predominantly navigate the...
Hepatic Drug Excretion: Influencing Factors
Drug Delivery: Enteral Route

