Development of a fast and precise method for simultaneous quantification of the PLGA monomers lactic and glycolic acid by HPLC

Abstract

Poly(lactide- co -glycolide acid) (PLGA) is an extraordinary well-described polymer and has excellent pharmaceutical properties like high biocompatibility and good biodegradability. Hence, it is one of the most used materials for drug delivery and biomedical systems, also being present in several US Food and Drug Administration-approved carrier systems and therapeutic devices. For both applications, the quantification of the polymer is inalienable. During the development of a production process, parameters like yield or loading efficacy are essential to be determined. Although PLGA is a well-defined biomaterial, it still lacks a sensitive and convenient quantification approach for PLGA-based systems. Thus, we present a novel method for the fast and precise quantification of PLGA by RP-HPLC. The polymer is hydrolyzed into its monomers, glycolic acid and lactic acid. Afterwards, the monomers are derivatized with the absorption-enhancing molecule 2,4′-dibromoacetophenone. Furthermore, the wavelength of the derivatized monomers is shifted to higher wavelengths, where the used solvents show a lower absorption, increasing the sensitivity and detectability. The developed method has a detection limit of 0.1 µg/mL, enabling the quantification of low amounts of PLGA. By quantifying both monomers separately, information about the PLGA monomer ratio can be also directly obtained, being relevant for degradation behavior. Compared to existing approaches, like gravimetric or nuclear magnetic resonance measurements, which are tedious or expensive, the developed method is fast, ideal for routine screening, and it is selective since no stabilizer or excipient is interfering. Due to the high sensitivity and rapidity of the method, it is suitable for both laboratory and industrial uses.

Predicting the Miscibility and Rigidity of Poly(lactic-co-glycolic acid)/Polyethylene Glycol Blends via Molecular Dynamics Simulations

“…Experimental data would further support these observations in that PLGA solubility in water dramatically worsens above a certain size as it is well accepted that PLGA oligomers smaller than 1,100 g/mol are water soluble . Both values of v for PLGA in water and acetonitrile are in line with experimental polymer–solvent interactions measured by inverse gas cromatography (IGC). , …”

“… 46 Both values of v for PLGA in water and acetonitrile are in line with experimental polymer–solvent interactions measured by inverse gas cromatography (IGC). 47 , 48 …”

“…46 Both values of v for PLGA in water and acetonitrile are in line with experimental polymer−solvent interactions measured by inverse gas cromatography (IGC). 47,48 In addition to the radius of gyration, the persistence length P l was also estimated for the PEG and PLGA chains (Figure 2b), following the methods described in Section 2.3.2. Given that P l differs under Θ conditions as compared to a good solvent, 49 the persistence length of PLGA was computed in both acetonitrile and water and compared to that of PEG in water (P l = 0.37 ± 0.02 nm in good accordance with previous findings (P l = 0.37 ± 0.04 nm) (Figure 2b).…”

Quantitative analyses to estimate the bioaccessibility of a hydrolytically degradable cationic flocculant

“…Based on these consistent and repeatable results, the HPLC method suggested by YMC CO., Limited [ 21 ] is considered effective to analyze lactic acid in gastric and intestinal aqueous supernatants. This finding is also consistent with previous studies that relied on the same HPLC technique to analyze lactic acid and similar compounds [ 6 , 7 , 8 , 9 , 26 , 27 ].…”

Recent advances in polymeric drug delivery systems

“…Glycolic acid and lactic acid have employed in pharmaceutical technology to produce water-soluble glycolate and lactate from otherwise-insoluble active ingredients. They have found further to use in drug delivery, topical preparations, and cosmetics to adjust acidity and for its disinfectant and keratolytic properties [29,30]. Hyaluronic acid, which is a natural polymer, has the ability to target the CD44 over expressing cancer cells.…”