Reverse Micelle-Based Microencapsulation of Oxytetracycline Hydrochloride into Poly-d,l-Lactide-co-Glycolide Microspheres

Authors: Kim, Hyunjoo1; Lee, Beom-Jin2; Sah, Hongkee3

Source: Drug Delivery, Volume 14, Number 2, February 2007 , pp. 95-99(5)

Publisher: Informa Healthcare

Buy & download fulltext article:


Price: $35.96 plus tax (Refund Policy)


The objectives of this study were to solubilize oxytetracycline hydrochloride (HCl) in reverse micelles to prepare poly-d,l-lactide-co-glycolide (PLGA) microspheres and to explore parameters affecting its encapsulation efficiency. Oxytetracycline HCl was dissolved in the reverse micelles consisting of cetyltrimethylammonium bromide, water, and ethyl formate. A PLGA polymer was then dissolved in the reverse micellar solution, and a modified solvent quenching procedure was carried out to prepare PLGA microspheres. Encapsulation efficiencies of oxytetracycline HCl ranged from 2.3 ± 0.2 to 24.9 ± 4.6%, depending on experimental conditions. Important parameters affecting its encapsulation efficiency included the amounts of water used to prepare the reverse micelles and PLGA polymer. With regard to microsphere morphology, the reverse micellar process produced the microspheres with smooth and pore-free surfaces. In particular, their internal matrices did not possess hollow cavities that were frequently observed when a typical double emulsion technique was used to make microspheres. In summary, it was possible to encapsulate oxytetracycline HCl into PLGA microspheres via the ethyl formate-based reverse micellar technique. We also anticipate that the use of ethyl formate could avoid environmental and human toxicity issues associated with methylene chloride.

Keywords: Microencapsulation; Oxytetracycline HCl; Poly-d,l-Lactide-co-Glycolide; Reverse Micelles

Document Type: Research Article


Affiliations: 1: College of Pharmacy, Catholic University of Daegu, Hayang-Up, Gyeongsan City, Gyeongbuk, Korea 2: College of Pharmacy, Kangwon National University, Hyoja-Dong, Chuncheon City, Kangwon-Do, Korea 3: College of Pharmacy, Ewha Womans University, Daehyun-Dong, Seodaemun-Gu, Seoul, Korea

Publication date: February 1, 2007

More about this publication?
Related content


Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content

Text size:

A | A | A | A
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages. print icon Print this page