Diffusion of lidocaine hydrochloride from lipid microparticles

Lipid particles, as drug carriers, are of increasing research interest, because a sustained drug release and avoidance of side effects could be achieved by using them. Lidocaine hydrochloride is a very efficient local anesthetic, but it has a short effect. The objective was to prolong the effect of the drug by encapsulating lidocaine hydrochloride in phospholipids microparticles. Two different procedures were used for the preparation of phospholipids microparticles. In both cases, phosphatidylcholine and ysophosphatidylcholine were used for the preparation of microparticles in which 5 % w/w lidocaine hydrochloride solution was encapsulated. The standard Franz diffusion cell was used for the experimental diffusion rate determination. The obtained results show that diffusion rate from microparticles is significantly lower than from the lidocaine hydrochloride solution, which means that this kind of microparticles could be used for the prolonged drug release. There was no much difference in diffusion rates from microparticles obtained by different procedures. That indicates that only the composition of the particles membrane has an influence on the lidocaine hydrochloride release rate.