Gamma scintigraphic evaluation of floating gastroretentive tablets of metformin HCl using a combination of three natural polymers in rabbits.
The present research was aimed at formulating a metformin HCl sustained-release formulation from a combination of polymers, using the wet granulation technique. A total of 16 formulations (F1-F16) were produced using different combinations of the gel-forming polymers: tamarind kernel powder, salep (palmate tubers of Orchis morio), and xanthan. Post-compression studies showed that there were no interactions between the active drug and the polymers. Results of in vitro drug-release studies indicated that the F10 formulation which contained 5 mg of tamarind kernel powder, 33.33 mg of xanthan, and 61.67 mg of salep could sustain a 95% release in 12 hours. The results also showed that F2 had a 55% similarity factor with the commercial formulation (C-ER), and the release kinetics were explained with zero order and Higuchi models. The in vivo study was performed in New Zealand White rabbits by gamma scintigraphy; the F10 formulation was radiolabeled using samarium (III) oxide ((153)Sm2O3) to trace transit of the tablets in the gastrointestinal tract. The in vivo data supported the retention of F10 formulation in the gastric region for 12 hours. In conclusion, the use of a combination of polymers in this study helped to develop an optimal gastroretentive drug-delivery system with improved bioavailability, swelling, and floating characteristics.
Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Mahboubeh
M
Razavi
Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Hamed
H
Karimian
Department of Biomedical Imaging and University Malaya Research Imaging Centre, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Chai Hong
CH
Yeong
Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Lip Yong
LY
Chung
Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Shaik
S
Nyamathulla
Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia ; Center for Natural Products and Drug Discovery (CENAR), Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
Mohamed Ibrahim
MI
Noordin
D000818:Animals; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D065546:Drug Liberation; D005079:Excipients / Q000737:chemistry*; D005772:Gastrointestinal Transit; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics; D008297:Male; D008687:Metformin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D011108:Polymers / Q000737:chemistry*; D011817:Rabbits; D011868:Radioisotopes / Q000032:analysis; D012493:Samarium / Q000032:analysis; D012995:Solubility; D013607:Tablets
D003692:Delayed-Action Preparations; D005079:Excipients; D007004:Hypoglycemic Agents; D011108:Polymers; D011868:Radioisotopes; D013607:Tablets; D012493:Samarium; D008687:Metformin
gamma scintigraphy; gastroretentive drug delivery; salep; sustain-release study; tamarind seed; xanthan