Analysis of Epidemiology Models by Non Standard Finite Difference Scheme and Laplace Adomian Decomposition Method

Abstract

The present work has been planned through rational designing to develop targeted drug delivery system for alfuzosin HCl. Alfuzosin is basically selective antagonist of alpha 1 adrenoreceptors, indicated for treating benign prostatic hyperplasia. Its dose is 2.5 mg thrice daily and the treatment plan includes steady-state concentration of the drug throughout course of therapy. Due to readily absorbance and development of postural hypotension, it is not being indicated for treatment of hypertension. Through this research project, development of targeted systems like hydrogels and floating drug delivery system has been made in order to control the release of drug molecule. Regarding hydrogels; two different types of pH dependant three dimensional polymeric networks have been developed through free radical polymerization. In first phase; nine different formulations of pectin (Pec) have been evaluated in combination with acrylic acid and crosslinked through glutaraldehyde. In second phase; various grades of poly (ethylene glycol) (PEG) (Mw 400, 4000, 8000, 10000, 12000 & 20000) have been crosslinked with acrylic acid through N,N,,-Mehtylene-bis-acrylamide (MBAAm). After development of discs, these model systems were envisaged for various important elucidations like swelling studies, In-Vitro drug release analysis, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (X RD) and Scanning Electron Microscopy (SEM). In order to predict releasing site and pattern; both dynamic and equilibrium swelling studies were conducted and implementation of various kinetic models has helped to elucidate kinetics of released molecule more efficiently. For both of the systems, frequency variations indicated by FTIR spectrum revealed interaction between the used polymers and monomers. Thermal stability has been reported by thermo gravimetric analysis while after copolymerization; increased enthalpy characters have been reported. In pectin based formulations, release of the drug followed zero order rates while in case of PEG based formulations; variations were reported in both rate and mechanism of drug release along with variations of molecular weights used. In both type of formulations, the drug release data is closely related to the swelling study’s findings and there is development of common character i.e. release of maximum amount of drug at pH 7.5. In floating drug delivery system, direct compression methodology has been adopted. The study has been aimed at developing floating system with non effervescent mechanism by using hydroxypropyl methylcellulose (HPMC) K100M, microcrystalline cellulose (MCC) PH 102, carbopol® and three grades of poly (ethylene glycol) (MW 10,000, 12,000 and 20,000). Various pre-compressional (angle of repose, compressibility index and Hausner’s ratio) and post compressional parameters (In-vitro buoyancy test, thickness, diameter, hardness, friability and In-vitro dissolution test) have been conducted to evaluate the suitability of developed dosage form for floating drug delivery system. The study is more focused towards evaluation of three grades of PEG (MW 10000, 12000, 20000) as all other parameters have been used as a constant quantity. Good matrix integrity has been found as all the formulations have presented total flotation time for more than 24 hours without disintegration. The formulation which doesn’t contain PEG has demonstrated first order along with fickian transport mechanism while all other formulations showed variation in their kinetic profile as the quantity and type of PEG varied. On the bases of revealed data of hydrogel and floating drug delivery system characterizations, it can be concluded that these systems are capable of delivering the drug molecule to the desired site in a predetermined mode of release.