Design and development of liposomes for colon targeted drug delivery.
BACKGROUND
Local delivery to bowel tissue through oral administration is a challenging but a desirable goal to treat diseases like inflammatory bowel disease (IBD). Colon specific drug delivery system should be capable of protecting the drug en route colon.


OBJECTIVE
Liposomes have shown potential to specific accumulation at inflammation site thus reduce toxicity; hence it can be used for effective treatment of IBD.


METHODS
Liposomes prepared using thin film hydration method. Statistical design was used for optimization. Colitis was induced using acetic acid. Inverted sac method was used as ex vivo model for IBD. Myeloperoxidase (MPO) activity and histopathology comparative study was carried out. Liposomes were formulated in enteric coated capsules to deliver the liposome specifically in initial segment of colon.


RESULTS
Particle size and entrapment efficiency were between 200 and 300 nm and 40 and 60%, respectively. In vivo and ex vivo study indicates higher accumulation of liposomes in colonic region as compared to pure drug. Enteric coated capsules delivered the drug after 5 h lag time.


CONCLUSIONS
Low particle size is attributed to low lipid content and stabilization due to surfactant. At higher cholesterol level, vesicles cannot reshuffle into smaller vesicles due to rigidization. Study shows higher accumulation of liposomes due to its lipoidal nature as compared to pure drug due to membrane transfer mechanism of drug thus MPO significantly lowers as compared to standard group (p < 0.05).


CONCLUSIONS
Higher accumulation of liposomal drug in inflammatory area and specific release of liposomes by enteric coated capsules provide better option for the treatment of colonic disease.
Department of Quality Assurance, AISSMS College of Pharmacy, University of Pune, Pune, Maharashtra, India.
Anand S
AS
Gupta
Sanjay J
SJ
Kshirsagar
Mangesh R
MR
Bhalekar
Tina
T
Saldanha
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D019819:Budesonide / Q000008:administration & dosage*; D002152:Calorimetry, Differential Scanning; D003106:Colon / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding; D015195:Drug Design; D004355:Drug Stability; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy* / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D008081:Liposomes; D008297:Male; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D009195:Peroxidase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
D000893:Anti-Inflammatory Agents; D004337:Drug Carriers; D008081:Liposomes; D019819:Budesonide; D009195:Peroxidase