TY - JOUR
T1 - Formulation and release behavior of doxycycline-alginate hydrogel microparticles embedded into pluronic F127 thermogels as a potential new vehicle for doxycycline intradermal sustained delivery
AU - Giovagnoli, Stefano
AU - Tsai, Tsuimin
AU - Deluca, Patrick P.
PY - 2010/3
Y1 - 2010/3
N2 - The aim of this work was the formulation and characterization of alginate (ALG)-doxycycline (DOX) hydrogel microparticles (MPs) embedded into Pluronic F127 thermogel for DOX intradermal sustained delivery. ALG-DOX MPs were formed by adding a solution of the drug into a 1.5% polymer solution while stirring. The MPs were cross-linked by dispersion into a 1.2% CaCl2 solution. Free MPs were characterized in terms of size, drug content, and release behavior by HPLC and UV-vis. DOX and hydrogel MPs were embedded into PF127, PF127-HPMC, and PF127-Methocel thermogels. The thermogels were characterized in terms of gelling time, morphology, and release behavior. A target release period of 4-7 days was considered optimal. The hydrogel MPs were about 20 μm in size with 90% of the population <59 μm. Drug content was about 35% (w/w). DOX released rapidly from the MPs, 90% within 2 days. An expected faster release was observed for free DOX from the thermogels with 80-90% of drug released after 3.5-4 h even in the presence of 1% HPMC or Methocel. The release was sustained after embedding the MPs into PF127 and PF127-HPMC thermogels. In particular, the PF127-HPMC thermogel showed an almost linear release, reaching 80% after 3 days and 90% up to 6 days. Although a further characterization and formulation assessment is required to optimize MP characteristics, ALG/DOX-loaded hydrogel MPs, when embedded into a PF127-HPMC thermogel, show a potential for achieving a 7-day sustained release formulation for DOX intradermal delivery.
AB - The aim of this work was the formulation and characterization of alginate (ALG)-doxycycline (DOX) hydrogel microparticles (MPs) embedded into Pluronic F127 thermogel for DOX intradermal sustained delivery. ALG-DOX MPs were formed by adding a solution of the drug into a 1.5% polymer solution while stirring. The MPs were cross-linked by dispersion into a 1.2% CaCl2 solution. Free MPs were characterized in terms of size, drug content, and release behavior by HPLC and UV-vis. DOX and hydrogel MPs were embedded into PF127, PF127-HPMC, and PF127-Methocel thermogels. The thermogels were characterized in terms of gelling time, morphology, and release behavior. A target release period of 4-7 days was considered optimal. The hydrogel MPs were about 20 μm in size with 90% of the population <59 μm. Drug content was about 35% (w/w). DOX released rapidly from the MPs, 90% within 2 days. An expected faster release was observed for free DOX from the thermogels with 80-90% of drug released after 3.5-4 h even in the presence of 1% HPMC or Methocel. The release was sustained after embedding the MPs into PF127 and PF127-HPMC thermogels. In particular, the PF127-HPMC thermogel showed an almost linear release, reaching 80% after 3 days and 90% up to 6 days. Although a further characterization and formulation assessment is required to optimize MP characteristics, ALG/DOX-loaded hydrogel MPs, when embedded into a PF127-HPMC thermogel, show a potential for achieving a 7-day sustained release formulation for DOX intradermal delivery.
KW - Doxycycline
KW - Hydrogel microparticles
KW - Sustained release
KW - Thermogel
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U2 - 10.1208/s12249-009-9361-8
DO - 10.1208/s12249-009-9361-8
M3 - Article
C2 - 20127210
AN - SCOPUS:77950917460
SN - 1530-9932
VL - 11
SP - 212
EP - 220
JO - AAPS PharmSciTech
JF - AAPS PharmSciTech
IS - 1
ER -