title: Development of repaglinide microspheres using novel acetylated starches of bitter and Chinese yams as polymers.
abstract: Tropical starches from Dioscorea dumetorum (bitter) and Dioscorea oppositifolia (Chinese) yams were acetylated with acetic anhydride in pyridine medium and utilized as polymers for the delivery of repaglinide in microsphere formulations in comparison to ethyl cellulose. Acetylated starches of bitter and Chinese yams with degrees of substitution of 2.56 and 2.70 respectively were obtained. Acetylation was confirmed by FTIR,1H NMR spectroscopy. A 32factorial experimental design was performed using polymer type and drug-polymer ratio as independent variables. Particle size, swelling, entrapment and time for 50% drug release (t50) were dependent variables. Contour plots showed the relationship between the independent factors and the response variables. All variables except swelling increased with drug: polymer ratio. Entrapment efficiency was generally in the rank of Bitter yam>Ethyl cellulose>Chinese yam. Repaglinide microspheres had size 50±4.00 to 350±18.10μm, entrapment efficiency 75.30±3.03 to 93.10±2.75% and t503.20±0.42 to 7.20±0.55h. Bitter yam starch gave longer dissolution times than Chinese yam starch at all drug-polymer ratios. Drug release fitted Korsmeyer-Peppas and Hopfenberg models. Acetylated bitter and Chinese yam starches were found suitable as polymers to prolong release of repaglinide in microsphere formulations.
authors: Department of Pharmaceutics & Industrial Pharmacy, University of Ibadan, 200284, Ibadan, Nigeria; Department of Biopharmaceutical Sciences, College of Pharmacy, Roosevelt University, 1400 N. Roosevelt Blvd., Schaumburg, IL 60173, USA.
authors: Adenike
authors: A
authors: Okunlola
authors: Department of Biopharmaceutical Sciences, College of Pharmacy, Roosevelt University, 1400 N. Roosevelt Blvd., Schaumburg, IL 60173, USA.
authors: Amusa Sarafadeen
authors: AS
authors: Adebayo
authors: Department of Biopharmaceutical Sciences, College of Pharmacy, Roosevelt University, 1400 N. Roosevelt Blvd., Schaumburg, IL 60173, USA. Electronic address: madeyeye@roosevelt.edu.
authors: Moji Christianah
authors: MC
authors: Adeyeye
mesh_terms: D000089:Acetic Anhydrides / Q000737:chemistry; D000107:Acetylation; D002219:Carbamates / Q000737:chemistry*; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D027742:Dioscorea / Q000737:chemistry*; D004337:Drug Carriers; D004339:Drug Compounding; D065546:Drug Liberation; D005163:Factor Analysis, Statistical; D007004:Hypoglycemic Agents / Q000737:chemistry*; D007700:Kinetics; D008863:Microspheres; D010316:Particle Size; D010880:Piperidines / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry; D012996:Solutions; D013213:Starch / Q000737:chemistry* / Q000302:isolation & purification; D013816:Thermodynamics
chemical_list: D000089:Acetic Anhydrides; D002219:Carbamates; D004337:Drug Carriers; D007004:Hypoglycemic Agents; D010880:Piperidines; D010936:Plant Extracts; D011725:Pyridines; D012996:Solutions; C031800:acetic anhydride; C072379:repaglinide; C013517:ethyl cellulose; D002482:Cellulose; D013213:Starch; C023666:pyridine
keywords: Acetylation; Dioscorea starches; Repaglinide microspheres