Comparison of Dialysis and Dispersion Methods for In Vitro Release Determination of Drugs from Multilamellar Liposomes

Abstract

The aim of these studies was to compare dialysis and dispersion methods for determining in vitro release of propranolol, metoprolol, pindolol, and atenolol from multilamellar liposomes. Multilamellar vesicles (MLV) were prepared using hydrogenated soy-lecithin phospholipon 90H (Ph 90H) as the primary lipid. The same volume of pH 7.4 phosphate buffered saline was used as a receptor medium for both methods. Samples were withdrawn, and drug concentration was determined using HPLC. All drug-containing liposomes exhibited an initial burst release followed by a slower rate of release. The rate and extent of drug release from MLV was dependent on the physicochemical properties of the drug. For all drugs investigated, the rate of release was higher for the dispersion method as compared with the dialysis method.

Challenges in design of translational nanocarriers

“…3A illustrates two examples, ideal one for the case when the carrier retains the drug during the transport in the blood compartments and the tumor tissue, but releases it in the tumor cells, and the other for a typical case of undesirable burst release when the carrier releases its drug cargo prematurely while still circulating in the blood. Such a burst release is generally observed for polymer particles [9][10][11] and liposomes [12,13]. As a result, the drug is dumped in the blood compartments, which causes not only local or systemic toxicity, but also lowers drug availability to the tumor and thereby therapeutic efficacy.…”

Betamethasone Dipropionate Gel for Treatment of Localized Plaque Psoriasis

“…At predetermined time intervals; 2 ml aliquots of the release medium was sampled and replaced with 2 ml fresh Eth-HS solution. The samples were suitably diluted with Eth-HS solution and the drug concentration was measured spectrophotometry at λR maxR of 238 nm [20]. Drug concentration was determined using the previously prepared standard curve of BD in Eth-HS solution and all experiments were conducted in triplicates.…”

“…The shear stress in dyne/cmP 2 P and the viscosity in centipose were determined at a different shear rate (2,6,10,20,24,60, 100 and 120 secP -1 P ) using spindle number 52.…”

Nanomechanics of electrospun phospholipid fiber

“…1,2 Phospholipids have therefore been used to prepare biomimetic capsular structures (mainly liposomes or micelles), [3][4][5][6] films, coatings for water microdroplets, 2 and microbubbles 7 with a broad range of applications, including drug delivery, 8 cell encapsulation, 9 and tissue engineering. McKee and co-authors 10,11 have shown that a solution of phospholipids above 35% w/w in DMF:CHCl3 [3:2 v/v] is capable of forming continuous fibers using electrospinning processing with an average phospholipid fiber diameter of $3.3 lm (for 45% w/w solution).…”