Impact of the experimental conditions on drug release from parenteral depot systems: From negligible to significant.

The aim of this study was to evaluate the impact of the experimental conditions on drug release measurements from parenteral depot systems. Frequently applied setups were used, including agitated and "non-agitated" flasks and tubes, flow-though cells as well as agarose gels. The bulk fluid volumes and flow rates were varied.

MALDI-TOF MS imaging of controlled release implants.

MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) imaging is used to characterize novel lipid implants allowing for controlled drug delivery. Importantly, this innovative technique provides crucial information on the inner structure of the implants before and after exposure to the release medium and does not require the addition of marker substances. Implants were prepared by extrusion at room temperature.

Cast lipid implants for controlled drug delivery: importance of the tempering conditions.

Lipid implants prepared by melting and casting offer a great potential for advanced drug delivery. However, care must be taken with respect to the solid state of the lipid(s) and potential changes thereof during storage. Generally, a thermal aftertreatment is required.

Controlled release implants based on cast lipid blends.

The aim of this study was to use lipid:lipid blends as matrix formers in controlled release implants. The systems were prepared by melting and casting and thoroughly characterized before and after exposure to the release medium. Based on the experimental results, a mechanistic realistic mathematical model was used to get further insight into the underlying drug release mechanisms.

Drug release mechanisms of cast lipid implants.

The aim of this work was to better understand which physicochemical processes are involved in the control of drug release from lipid implants prepared by melting and casting. Lipid implants gain steadily in importance as controlled parenteral drug delivery systems: In contrast to PLGA-based devices, no acidic microclimates are created, which can inactivate incorporated drugs. The melting and casting method offers various advantages over the commonly used direct compression technique.

Drug release mechanisms of compressed lipid implants.

The aim of this study was to elucidate the mass transport mechanisms controlling drug release from compressed lipid implants. The latter steadily gain in importance as parenteral controlled release dosage forms, especially for acid-labile drugs. A variety of lipid powders were blended with theophylline and propranolol hydrochloride as sparingly and freely water-soluble model drugs.

Lipid implants as drug delivery systems.

The parenteral controlled delivery of acid-labile drugs (e.g., proteins) is difficult, because the standard polymer poly(lactic-co-glycolic acid) used to control drug release upon parenteral administration degrades into shorter chain acids, creating acidic microclimates.

Drug release from lipid-based implants: elucidation of the underlying mass transport mechanisms.

The aim of this study was to better understand the mass transport mechanisms involved in the control of drug release from lipid-based implants. Different types of triglyceride-based cylinders were prepared by compression. Glycerol-trilaurate, -trimyristate, -tripalmitate and -tristearate were used as model lipids, lysozyme and pyranine as model drugs.