Ammonolysis-based microencapsulation technique using isopropyl formate as dispersed solvent

Recent Trends in Preparation of Poly(lactide-co-glycolide) Nanoparticles by Mixing Polymeric Organic Solution with Antisolvent

“…Class 3 solvents with low toxic potential are favored in the pharmaceutical industry. Representative examples of Class 3 solvents used for the preparation of PLGA particles are acetone, ethyl acetate, butyl acetate, isopropyl formate, and glycofurol [197][198][199][200][201][202][203][204][205][206]. As shown in Table 3, acetone is the most predominantly used solvent for nanoprecipitation, but it exerts poor solvation power for high-molecular-weight PLGA polymers and certain hydrophobic drugs.…”

Applicability of non-halogenated methyl propionate to microencapsulation

“…When microspheres were prepared using ethyl acetate, the resultant microspheres displayed quite similar trends as described above ( Figure 7B). Interestingly, the maintenance of the physical status of progesterone is quite contrasting to the occurrence of its polymorphic transition into the b form during the ammonolysis-based microencapsulation process reported elsewhere (Lim and Sah, 2009). These contradictory results suggest that solvent type, manufacturing process, and the rate of solvent removal might closely interplay to decide the physical status of a drug during microencapsulation.…”

“…The solutions were subject to an HPLC analytical procedure, as described by Lim and Sah (2009). Briefly, one part of the tetrahydrofuran solution was diluted with five parts of methanol.…”

“…In the pharmaceutical industry, the preferred solvents for preparing poly-D,L-lactide-co-glycolide (PLGA) microspheres are usually ICH Class 3 solvents. Relevant examples are acetic acid, acetone, acetonitrile, butyl acetate, ethyl acetate, isopropyl formate, and glycofurol (Herrmann and Bodmeier, 1998;Wang and Wang, 2002;Castellanos and Griebenow, 2003;Meng et al, 2003;Yeo et al, 2003;Matsumoto et al, 2008;Hamishehkar et al, 2009;Lim and Sah, 2009;Obeidat, 2009;Allhenn and Lamprecht, 2011). The use of acetic acid, acetone, and acetonitrile is limited only to certain PLGA polymers with low molecular weights, because they are not capable of dissolving those with high molecular weights.…”

Meeting the unmet: from traditional to cutting-edge techniques for poly lactide and poly lactide-co-glycolide microparticle manufacturing

“…This process can have significative relevance with acidic API, since an acidic aqueous phase will limit their diffusion and loss in the continuous phase. Other papers used isopropyl formate (Im and Sah 2009) or methyl chloroacetate (Kim et al 2007) as organic phase and their removal was carried out using ammonia solution that provoked solvent hydrolysis obtaining water-miscible formamide and isopropyl alcohol or chloroacetamide and methanol, respectively. As a result, the polymer precipitated encapsulating progesterone, used as a model API, with an encapsulation efficiency in the 64-97% range (Kim et al 2007;Im and Sah 2009).…”