TY - JOUR
T1 - In vitro release kinetic pattern of indomethacin from Poly(D, L‐Lactide) nanocapsules
AU - Ammoury, Nazih
AU - Fessi, Hatem
AU - Devissaguet, J. P.
AU - Puisieux, F.
AU - Benita, S.
PY - 1990/9
Y1 - 1990/9
N2 - Indomethacin nanocapsules were prepared by interfacial deposition of poly(D, L‐lactide) polymer following displacement of acetone from a lipophilic phase to an aqueous phase. Highly solvated bilayers of phospholipids in excess in the formulation were formed and easily detected by TEM. In vitro release kinetic analysis of indomethacin from pure nanocapsules prepared with poloxamer as sole emulsifier, mixed colloidal suspension (nanocapsules and liposomal vesicules), and multilamellar phospholipidic bilayers revealed that drug release in phosphate buffer sink solution was drastically delayed and incomplete as a result of the high indomethacin solubility in the oily core, poloxamer micelles, and phospholipidic bilayers, respectively. The release process was thus dependent on drug partition from the colloidal suspension phases to the external sink solution. However, addition of albumin to the sink solution markedly enhanced the indomethacin release due to protein binding affinity. A kinetic model equation dealing with biphasic systems in which a drug is dissolved or partitioned between the lipophilic and hydrophilic phases of a dispersed system is proposed and found suitable for the description of indomethacin release from the mixed colloidal suspension only.
AB - Indomethacin nanocapsules were prepared by interfacial deposition of poly(D, L‐lactide) polymer following displacement of acetone from a lipophilic phase to an aqueous phase. Highly solvated bilayers of phospholipids in excess in the formulation were formed and easily detected by TEM. In vitro release kinetic analysis of indomethacin from pure nanocapsules prepared with poloxamer as sole emulsifier, mixed colloidal suspension (nanocapsules and liposomal vesicules), and multilamellar phospholipidic bilayers revealed that drug release in phosphate buffer sink solution was drastically delayed and incomplete as a result of the high indomethacin solubility in the oily core, poloxamer micelles, and phospholipidic bilayers, respectively. The release process was thus dependent on drug partition from the colloidal suspension phases to the external sink solution. However, addition of albumin to the sink solution markedly enhanced the indomethacin release due to protein binding affinity. A kinetic model equation dealing with biphasic systems in which a drug is dissolved or partitioned between the lipophilic and hydrophilic phases of a dispersed system is proposed and found suitable for the description of indomethacin release from the mixed colloidal suspension only.
UR - http://www.scopus.com/inward/record.url?scp=0025180647&partnerID=8YFLogxK
U2 - 10.1002/jps.2600790902
DO - 10.1002/jps.2600790902
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
C2 - 2273454
AN - SCOPUS:0025180647
SN - 0022-3549
VL - 79
SP - 763
EP - 767
JO - Journal of Pharmaceutical Sciences
JF - Journal of Pharmaceutical Sciences
IS - 9
ER -