In Situ Implant for the Treatment of Prostate Cancer

Abstract

A controlled release parenteral dosage form is usually selected when there are problems associated with oral delivery (e.g. gastric irritation, first pass effects or poor absorption) and a need for extended release and/or targeted drug delivery (e.g. rapid clearance, toxic side effects). Parenteral injection is so far a preferred method to deliver polypeptides; however, due to their short plasma half-live, gastric degradation, daily multiple injections are needed. This reduces the patient’s compliance, increases the need for medical supervision, and causes the drug plasma concentration fluctuation. Injectable implants, as novel drug delivery systems, proved as very promising in protein drugs delivery. These systems are liquid, which are injected subcutaneously or intramuscularly and deform to semisolid or solid matrices when come in contact with aqueous fluids in body or release media and release their drug in a controlled manner. The protein (DCPT 142) has half life of 4-5 hrs therefore; it was decided to formulate in situ implant it which provides drug release up to 1 month (28 days) and thereby helpful in treatment of prostate cancer. During preliminary in vitro drug release study it was revealed that initial burst release of from ISI were depend on grade of PLGA, its concentration an combination, solvent and its concentration, Drug release rate upto initial 6Hr were taken as responses. The results of release study revealed that grade of PLGA and solvent system plays a important role in controlling initial burst release of drug. Batch B3 comprising PLGA X selected as a in situ gelling polymer (40 % w/w), NMP (60 % w/w) as a water miscible solvent showed more than 85% drug release upto 28 days and considered as optimized formulation. Thus it was concluded that in developed situ implant system considered as a promising drug delivery system of proteins.