Related Experiment Video
Updated: Jul 14, 2025

Author Spotlight: Developing a Disposable Dosator for Preclinical Testing of Dry Powder Inhalers in Small Animal Models
Published on: August 18, 2023
Optimizing formulation parameters for the development of carvedilol injectable in situ forming depots
Majd Alrashdan1, Ziad A Shraideh2, Samer R Abulateefeh1
1School of Pharmacy, The University of Jordan, Amman, Jordan.
Abstract:
In situ forming depots (ISFDs) represent attractive alternatives to the conventional sustained drug delivery systems. Carvedilol, a short half-life drug used on a daily basis to manage chronic conditions, could benefit from this technology. The aim of this work was to develop, for the first time, a new injectable long-acting carvedilol-ISFD. Accordingly, 4 different grades of polyesters with varying properties as i) lactide-to glycolide ratio (polylactide-co-glycolide (PLGA) vs. polylactide (PLA)), and ii) end functionality (acid- vs. ester-capped) were utilized for the preparation of ISFD formulations. In addition, 4 different organic solvents with varying properties (i.e. N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), ethyl acetate, and benzyl benzoate) were also investigated. It was found that NMP and DMSO were more suitable for the formation of depots. Furthermore, all ISFD formulations demonstrated excellent encapsulation efficiency (i.e. 96-98%). Interestingly, both PLGA-based ISFDs (acid-capped and ester-capped) exhibited similar release behaviors and were able to extend carvedilol release over 30 days. On the other hand, acid-capped and ester-capped PLA-based ISFDs exhibited slower release over the 30 days with an average release of only 36% and 60%, respectively. In conclusion, the developed carvedilol-ISFDs resulted in a tunable extended-release behavior, simply by choosing the appropriate grade of polymer. These results open the door toward a novel injectable carvedilol-ISFD formulation.
Related Concept Videos
Factors Influencing Drug Absorption: Pharmaceutical Parameters
One-Compartment Open Model for IV Bolus Administration: General Considerations
The drug's presence in the body is defined by an equation representing the difference between the rates of drug entry and exit. Key parameters—elimination rate constant,...
One-Compartment Open Model for IV Bolus Administration: Estimation of Clearance
In the one-compartment open model for intravenous (IV) bolus administration, clearance is estimated by dividing the elimination rate by the plasma drug concentration. This equation leverages the elimination rate constant and the apparent...
Nonlinear Pharmacokinetics: Drug Elimination for IV Bolus Injection
Following the administration of a single intravenous (IV) bolus injection, we can determine the concentration of the drug in the plasma at any given time. This calculation is achieved using a specific equation that integrates the values of Vmax and KM.
We can also...
Biopharmaceutics and Pharmacokinetics: Overview
One-Compartment Open Model for IV Bolus Administration: Estimation of Elimination Rate Constant, Half-Life and Volume of Distribution

