Biodegradable polymeric injectable implants for long‐term delivery of contraceptive drugs

Abstract

Development of injectable, long-lasting, contraceptive drug delivery formulations and implants are highly desired to avoid unplanned pregnancies while improving patient compliance and reducing adverse side effects and treatment costs. The present study reports on the fabrication and characterization of two levonorgestrel (LNG) microsphere injectable formulations. Poly(ε-caprolactone) (PCL) with 12.5% and 24% (w/w) LNG were fabricated into microspheres, measuring 300±125 μm, the oil-in-water (o/w) emulsion solvent evaporation technique. Formulations showed sustained drug release up to 120 days. FTIR, XRD, DSC, and TGA confirmed the absence of LNG chemical interaction with PCL as well as its molecular level distribution. The release of LNG was calculated to be Fickian diffusion controlled and properly characterized. The inclusion of multiple elevated release temperatures allowed for the application of the Arrhenius model to calculate drug release constants and representative sampling intervals, demonstrating the use of elevated temperatures for accelerated-time drug release studies.

Direct Metal‐Free Preparation of Functionalizable Polylactic Acid‐Ethisterone Conjugates in a One‐Pot Approach

“…Specifically, the value of A E is controlled to the equal of A T between 40 and 60, and the value of A E is controlled to the twice of A T between 80 and 120 (Figure ). Herein, the concentration of conjugated drug ES can be more than 67 mg mL −1 (Table ), which reaches to the drug loading levels of physical methods . Thus, to achieve the controllability of drug loading in DDS, highly efficient DMP chemical conjugation synchronously combing of polymeric carrier preparation and drug loading into a facile one‐step procedure can be used to replace the physical method containing tedious steps.…”

“…In order to expand the biological application of steroids drug controlled‐release systems, the biological property of PLA‐ES system was further tested preliminarily. The antibacterial efficacy of PLA‐ES conjugate against E. coli was measured by an antibiogram assay .…”

“…As a series of steroids with good bioactivities, estrogens have been exploited in the controlled‐release systems, such as microspheres (especially using PLAs material as carrier), nano‐fibers, gels . Most of them are prepared by solvent volatilization, impregnation, electrostatic spinning, and other physical technologies to improve continuous and sustained releasing performance of drug and its encapsulation rate.…”

Preparation and characterization of novel anti-inflammatory biological agents based on piroxicam-loaded poly-ε-caprolactone nano-particles for sustained NSAID delivery

“…Between the various biodegradable polymers, poly-e-caprolactone (PCL) has been considered as a drug carrier due to its good properties, such as biodegradability, biocompatibility, and high permeability to micro-molecular drugs (Mei et al, 2018;Zupan ci c et al, 2018;. Also, the mild and long-lasting PCL degradability is another good feature that makes it a suitable vehicle for sustained delivery of PX (Manoukian et al, 2018). On the other hand, the use of collagen that is able to absorb, associate and interact with NPs, has a great impact on their biological behavior (Kandamachira et al, 2015).…”

Synthesis and characterization of a novel stimuli‐responsive magnetite nanohydrogel based on poly(ethylene glycol) and poly(N‐isopropylacrylamide) as drug carrier

“…In addition, hydrogel/metal nanoparticles systems are more interesting in part due to their ability to overcome challenges associated with conventional drug delivery . In this context, hydrogels possesses magnetite nanoparticles (MNPs) which are of particular interest owing to combination of inherent physicochemical and biological characteristics of both materials .…”