Available online at www.scholarsresearchlibrary.com Scholars Research Library Der Pharmacia Lettre, 2015, 7 (7):124-136 (http://scholarsresearchlibrary.com/archive.html) ISSN 0975-5071 USA CODEN: DPLEB4 124 Scholar Research Library Regression analysis a tool for optimization of matrix systems Koushik Sen Gupta* and Lakshmi K. Ghosh Department of Pharmaceutical Technology, Jadavpur University, Kolkata, West Bengal, India _____________________________________________________________________________________________ ABSTRACT Salbutamol sulphate,a short acting highly selective beta 2 adrenoceptor agonist, used for the treatment of nocturnal asthma. The occurrence of nocturnal asthma is associated with increased morbidity and inadequate asthma control, and has an important negative impact on quality of life. Matrix tablets (Seven formulations F1 – F7) were prepared by direct compression technique using two different grades of hydrophilic polymerMethocel® K4M and K15M in varying ratios.Various rheological and physicochemical parameters were studied and complied with the in-house specifications for tested parameters. Drug excipient compatibility study was performed using Fourier Transform Infra-red spectroscopy and Differential Scanning Calorimetry. In-vitro drug release study was carried out in two different medium (initial 2 hrs in 700 ml 0.1 N HCl, and rest 10hrs add 200 ml 0.2 Mtrisodium phosphate to maintain pH 6.8) and nearly 86 to 96 % drug was released from the system. Scanning Electron Microscopic study was performed to observe the morphological changes of tablets before and after dissolution process. The data obtained from drug release study were fitted into different kinetic models to identify the pattern of drug release from the matrix systems. A linear regression analysis was used to optimize the release of salbutamol sulphate from hydrophilic matrix formulations using Analyse-it + General 1.73 softwaredemo versionto study different responses. On the basis of different equations obtained from the regression analysis, one more formulation (F8) was prepared by taking any combinations of above mentioned polymersfor the optimization of pharmaceutical formulations with desirable performance characteristics. Keywords: Salbutamol sulphate, Hydrophilic matrix tablets, Differential Scanning Calorimetry, Scanning Electron Microscopy, Linear regression analysis _____________________________________________________________________________________________ INTRODUCTION Pharmaceutical formulations are complex systems in which the properties and performance characteristics are influenced by numerous formulation and process factors that may not be easily understood. Pharmaceutical optimization has been defined as the implementation of systematic approaches to establish the best possible combination of materials and/or process variables under a given set of conditions that will result in the production of a quality pharmaceutical product with predetermined and specified characteristics each time it is manufactured [1]. Hydrophilic monolithic matrix devices are a popular choice for the manufacture of sustained release solid oral dosage forms due to their ease of manufacture and the extensive amount of information available regarding this well understood technology. The use of hydrophilic matrix formulations to control the release of drugs from pharmaceutical tablets is well documented [2–5]. The rate and mechanism of drug release from monolithic devices can be adjusted by the levels and types of polymer combinations that are used to manufacture a formulation. When hydrophilic matrix tablets are immersed in aqueous media, the polymer hydrates, swells and increases in size after which the matrix dissolves and/or erodes with time. Early studies have shown that drug release from swellable hydrophilic matrices is dependent on the thickness of the hydrated gel layer that is formed during the swelling phase of polymer hydration [6, 7]. The degree of swelling determines the diffusional path length of a drug and the thicker the gel layer, slower the rate of drug release from a matrix [8]. Drug release from hydrophilic matrix formulations