Preparation and evaluation of bromocryptine mesylate-polydimethylsiloxane matrices

The aims of the present study were to characterize the compatibility of silicone polymers with bromocryptine mesylate and excipients and to investigate the in vitro release characteristics of the drug from polydimethylsiloxane matrices. Silicon elastomers, MDX-4-4210 and A-2186, were chosen as polymer materials. Compatibility studies of polymers with drug and various liquid and solid excipients such as propylene glycol, polyethylene glycol, glycerol, sorbitan monolaurat, polysorbate 20, polysorbate 80, polyvinylpyrrolidone, citric acid, lactose, sodium chloride and low-molecular-weight gelatin were carried out. After the macroscopic examination of the excipient-polymer formulations, sorbitan monolaurat, propylene glycol, lactose, sodium chloride, citric acid and low molecular weight gelatin were chosen for investigation of the effect of these materials on drug release. Cylinder-shaped drug polymer matrices were prepared for the drug release studies. The best release profile was obtained with the formulation containing MDX-4-4210, 10% of propylene glycol and a kneading mixture of drug: low-molecular-weight gelatine in a ratio of 1:3.