Design development and evaluation of gastro retentive drug delivery system by incorporation of nanoparticles or microspheres

Abstract

In view of formulating gastro retentive sustained release dosage form, we have successfully encapsulated the two drugs famotidine and captopril by different techniques. Modified spontaneous emulsification- solvent diffusion was used for the generation of famotidine loaded PLGA nanoparticles wherein mucoadhesion was attained by using Carbopol as the mucoadhesive polymer. On the other hand ernulsification- solvent diffusion encapsulating captopril into porous carrier calcium silicate with the aid of matrix forming polymer Eudragit S 100 was used for the generation of floating microspheres of captopril. Farnotidine (FAM) is an I-12-receptor blocker used to treat duodenal ulcers, Zollinger-Ellison syndrome and reflux oesophagitis. It is classified as a BCS class IV drug, i.e. it is poorly water soluble, making it an ideal candidate for improving its solubility by particle size reduction. It has higher solubility in acidic medium and studies have been conducted which demonstrated the effectiveness of retaining FAM in the stomach, thus justifying its formulation into a gastroretentive dosage form. FAM has a dose of 20- 40 mg and a short half life, thereby justifying its development into a sustained release formulation. Thus famotidine was an ideal candidate to be formulated as a combined drug delivery system which encompassed the advantages of sustained release, gastroretentive, nanoparticulate system. newlineCaptopril, is an ACE inhibitor, i.e. anti-hypertensive drug. It belongs to Class III category. Also the drug has an absorption window in the stomach. In order to prevent burst release, mu ltiparticluate in the form of microspheres was adopted as a technique to formulate microspheres of CAP. In conclusion, it can be said that combining various strategies has shown an improvement in the bioavailability of FAN /I and CAP effectively. The strategies employed, excipients and equipments are routinely used and can very easily be scaled up. Thus it can be conclusively said that the goals envisaged have been fulfilled.