Abstract
The objective of this study was to identify, understand and generate a Taguchi orthogonal array model for the formation of 10–50 μm microparticles with applications in topical/ocular controlled drug delivery. Poly(lactic-co-glycolic acid) (PLGA) microparticles were fabricated by the single emulsion oil-in-water method and the particle size was characterized using laser diffraction and scanning electronic microscopy (SEM). Sequential Taguchi L12 and L18 orthogonal array (OA) designs were employed to study the influence of ten and eight parameters, respectively, on microparticle size (response). The first optimization step using the L12 design showed that all parameters significantly influenced the particle size of the prepared PLGA microparticles with exception of the concentration of poly(vinyl alcohol) (PVA) in the hardening bath. The smallest mean particle size obtained from the L12 design was 54.39 μm. A subsequent L18 design showed that the molecular weight of PLGA does not significantly affect the particle size. An experimental run comprising of defined parameters including molecular weight of PLGA (89 kDa), concentration of PLGA (20% w/v), concentration of PVA in the emulsion (0.8% w/v), solvent type (ethyl acetate), organic/aqeuous phase ratio (1:1 v/v), vortexing speed (9), vortexing duration (60 seconds), concentration of PVA in hardening bath (0.8% w/v), stirring speed of hardening bath (1200 rpm) and solvent evaporation duration (24 hours) resulted in the lowest mean particle size of 23.51 μm which was predicted and confirmed by the L18 array. A comparable size was demonstrated during the fabrication of BSA-incorporated microparticles. Taguchi OA design proved to be a valuable tool in determining the combination of process parameters that can provide the optimal condition for microparticle formulation. Taguchi OA design can be used to correctly predict the size of microparticles fabricated by the single emulsion process and can therefore, ultimately, save time and costs during the manufacturing process of drug delivery formulations by minimising experimental runs.
Highlights
Microparticles (MPs) may be designed to allow precise delivery of small quantities of potent drug and increase the local concentration of the drugs in the target tissue [1, 2]
MPs with smallest median diameter were obtained from an organic phase comprising of ethyl acetate (EAc) and 20% w/v poly(lactic-co-glycolic acid) (PLGA) polymer, and an aqueous phase of low molecular weight of 1.2% w/v poly(vinyl alcohol) (PVA) which were combined at a ratio of 1:1 to form a primary emulsion by a vortexing speed at scale 5 for 90 s
The largest particle size was registered with 10% w/v PLGA concentration, DCM, 0.3% w/v PVA in primary emulsion, vortexing speed at scale 5, vortexing duration of 45 s, 1:1 organic/aqueous phase ratio, 0.3% w/v PVA in hardening bath, 400 rpm stirring speed and 18 h evaporation duration (Run 1)
Summary
Microparticles (MPs) may be designed to allow precise delivery of small quantities of potent drug and increase the local concentration of the drugs in the target tissue [1, 2]. The fabrication of MPs depends on the choice of suitable polymeric materials. An ideal polymeric material must be non-toxic, biodegradable and biocompatible [4]. Poly(lactic-co-glycolic acid) (PLGA) was chosen for MP fabrication as it possesses the suitable properties, is readily available and approved by regulatory authorities (i.e. FDA) for clinical use in humans [5]. PLGA undergoes hydrolysis to generate lactic and glycolic acid which do not cause carrier toxicity or immunological response and explains the success of PLGA as a biodegradable polymeric material [6, 7]. When used for drug delivery, this hydrolysis leads to the degradation of the PLGA matrix and any drug incorporated within is liberated in a time-dependent fashion, typically over several weeks
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
