In vivo evaluation of a novel zero order drug releasing transdermal system of rotigotine
Background: Rotigotine is a new non-ergolinic dopamine agonist used in the treatment of Parkinson’s disorder and restless legs syndrome. It has extensive pre-systemic metabolism and administration of rotigotine through transdermal route is the best way to avoid pre-systemic metabolism and thereby to increase the bioavailability and to deliver the drug in a controlled order.
Objective: A controlled release transdermal system was developed using a novel hybrid technique including a combination of micro reservoir and adhesive dispersion system.
Materials and Methods: Transdermal system was prepared by incorporating rotigotine drug in adhesive matrix layer in which microspheres loaded with rotigotine were dispersed. Microspheres were prepared by spray drying technique using poly-ecaprolactone and maltodextrin (1:1 ratio) as carriers in various drug to polymer ratios.
Results: Microsphere composition comprising drug to polymer ratio 1:9 was found optimal for designing transdermal system. The optimized transdermal formulation comprised of 80 mg of silicon adhesive with 2.5 mg of rotigotine along with 20.1 mg of microspheres containing 2 mg of rotigotine.
Conclusion: From the PK study conducted in male wistar rats, it was observed that there was 1.679 folds improvement in bioavailability of test formulation when compared to reference (contains 4.5 mg of rotigotine pure crystalline drug in adhesive matrix layer) formulation.
Materials: Rotigotine USP (freebase) was received as a gift sample from Neuland Pharma, Hyderabad. Poly-e-caprolactone of (MW 14000) was procured from Sigma Aldrich, Germany. Povidone K90, Vitamin-E TPGS (D-α-tocopheryl polyethylene glycol succinate), Ascorbyl palmitate and DAlpha tocopherol of USP-NF grade were procured from BASF, Germany. Maltodextrin (Glucidex IT17, USP-NF) was procured form Roquette Pharma, France. Sodium metabisulfite (Ph. Eur.) grade was procured form Merck India. Aluminum vapor coated pigmented polyethylene polyester backing membrane (3M Scotchpack 1109) and Fluoropolyester coated release liner (3M Scotchpack 9744) were received as gift samples from 3M Corporation, USA. Silicon adhesive (7- 4302 BIO PSA, USP-NF) was procured from DOW Corning, USA. Methanol, Ethanol (99.9%), 2- propanol, tert-butyl methyl ether, Acetonitrile, Methanesulfonic acid, ethyl acetate and dichloromethane of HPLC grade were procured from Merck, India.
Article information: Sravanthi A., Sunitha M. Reddy, Jaswanth A., Asian Journal of Pharmacy and Pharmacology 2021;7(3):126-130.