Physicochemical characterization of a hydrophilic model drug-loaded PHBV microparticles obtained by the double emulsion/solvent evaporation technique

Abstract

Micropartículas de poli(3-hidroxibutirato-co-3-hidroxivalerato) (PHBV) contendo um fármaco modelo hidrofílico, o cloridrato de metformina (MH), foram obtidas pela técnica de emulsão múltipla/evaporação do solvente. Diversas formulações foram preparadas, com o objetivo de investigar a influência de cada composição sobre a eficiência de encapsulação (EE). O resultado mais elevado de EE (9,76%) foi verificado quando da simultânea alcalinização e adição de NaCl na fase aquosa externa da formulação. O estudo por MEV das micropartículas revelou morfologia esférica e superfície rugosa. As intensidades de difração cristalina para as micropartículas contendo o MH foram menores do que aquelas observadas para a mistura física. Os resultados obtidos por IVTF sugerem que nenhuma ligação química foi formada entre o polímero e o fármaco. A avaliação por análise térmica indica o surgimento de interações favoráveis entre MH e PHBV. O estudo de liberação in vitro demonstrou a influência do PHBV no perfil de dissolução do MH.Poly(3-hydroxybutirate-co-3-hydroxyvalerate) (PHBV) microparticles containing a watersoluble model drug, metformin hydrochloride (MH), were obtained by a double emulsion/solvent evaporation technique. Several formulations were prepared in order to investigate the influence of each composition on the encapsulation efficiency (EE). The highest value of EE (9.76%) was obtained using simultaneously pH alkalinization and NaCl addition in the external water phase of the formulation. SEM study revealed a spherical morphology and a rough surface. The crystalline diffraction intensities for the MH-loaded microparticles were lower than that verified for the physical mixture. FTIR results suggested that no chemical bond between the polymer and the drug was formed. Also thermal analyses indicated a favorable interaction between MH and PHBV. In vitro drug release demonstrated the influence of the PHBV on the dissolution profile of MH. Keywords: PHBV, double emulsion/solvent evaporation technique, hydrophilic model drug, microparticles IntroductionBiodegradable polymeric materials have been received increasing interest due to several ecological and recycling aspects. 1,2 Among numerous microbial polyesters, poly(3-hydroxybutirate-co-3-hydroxyvalerate) (PHBV) has been widely investigated as a biocompatible material suitable for pharmaceutical and medical applications. The literature reports the use of PHBV in tissue engineering and as drug delivery systems. [3][4][5][6][7][8][9][10][11][12] Particularly, PHBV exhibits unique and interesting physicochemical features (e.g. piezoelectricity) in addition to their mechanical properties similar to the polypropylene and other widely used polyesters [e.g. poly(DL-lactide) and poly(DL-lactide-co-glycolide)]. 13 Moreover, PHBV is a less crystalline biopolymer than poly(3-hydroxybutirate), therefore an enhanced degradation rate is observed. 14 Farago et al. 1299 Vol. 19, No. 7, 2008 Several methods have been used to prepare microparticles, for both natural and synthetic polymers. 15...

Preparation and characterization of 45S5 bioactive glass‐based scaffolds loaded with PHBV microspheres with daidzein release function

“…The absorption bands corresponding to PHBV microspheres [Figure (a)] were found at 1720 cm −1 due to the CO stretching. Characteristic bands from 800 to 975 cm −1 corresponded to the symmetric COC stretching vibration . Figure (b–f) show the absorption bands of the microsphere loaded scaffolds after 0, 3, 7, 14 and 28 days of immersion in SBF.…”

“…Characteristic bands from 800 to 975 cm 21 corresponded to the symmetric ACAOACA stretching vibration. 54 Figure 6(b-f) show the absorption bands of the microsphere loaded scaffolds after 0, 3, 7, 14 and 28 days of immersion in SBF. After 3 days of immersion the dual bands at 565 and 603 cm 21 were identified corresponding to the bending vibration of the PAO bond.…”

Formulation Evaluation of Extended-Release Solid Dispersion of Metformin Hydrochloride

“…[1] Unlike other biguanide drugs, metformin does not induce lactic acidosis. However, current metformin therapy is suboptimal as it is associated with a high incidence of gastrointestinal side effects, seen in about 30% of the patients, thus making the development of sustained-release forms desirable.…”

Produção E Caracterização De Micropartículas De Poli(ácido Lático-Co-Ácido Glicólico) (Plga) E Cloridrato De Metformina

“…Contudo, o baixo valor de PRE pode indicar que o composto ativo está molecularmente disperso em toda a micropartícula polimérica (Klose et al, 2011), sem a formação de agregados ou deposição de cristais de composto ativo na superfície da partícula. Adicionalmente, um estudo envolvendo o encapsulamento do CM em micropartículas de poli(3-hidroxibutirato-co-3-hidroxivalerato) (PHBV) utilizando a técnica da dupla emulsão também resultou em baixos valores de EE (Farago et al, 2008), demonstrando a dificuldade relacionada à incorporação de compostos ativos hidrofílicos de baixa massa molecular em micropartículas poliméricas usando esta técnica.…”