IN VITRO STUDY OF (IRON+FOLIC ACID) TABLETS AS SUSTAINED RELEASE FROM BIOPOLYMERIC HYDROPHILIC POLYMER

Abstract

The objective of the present research was to design a suitable uncoated matrix tablet that contains ferrous fumarate + folic acid. This tablet was designed in a way to be capable of giving the least release of drug in the first hour in acidic medium 0.1N HCl which simulated the gastric fluid. Moreover, it should be capable of giving not less than 90% in the maximum time in D.M Water at pH 6 dissolution medium which was considered to simulate the intestinal fluid. This sustained release dosage form would decrease gastro intestinal disturbances most likely caused by increasing the drug release in shorter time. Especially that combination is used second and third trimester of pregnancy asprophylaxis of iron & folic acid deficiency. In this research, several formulations containing hydrophilicpolymer HPMC, were prepared by wet granulation technique. Statistical Taguchi experimental method was used to study the impact of different content levels of HPMC, MCC, Starch and Lactose in: (1) physical characterization for granules and matrix tablet. Also (2) Drug release rate and its kinetics for hydrophilic matrix tablets compared with conventional tablets when studied in a variety of dissolution media, pH buffer media with and without addition of various surfactants, to perform this in vitro studies, USP paddle method II was used. The spectrophotometry method was used to analyse all withdrawn dissolution samples to determine the percentage of iron (Fe +2 ) released in the pre-determined times using spectrometer UV\VIS double beam at wavelength 510nm. The granules for all preparedformulations showed satisfactory flow and compressibility properties. All tablets showed acceptable pharmacotechmical properties and complied with inhouse specifications for tested parameters. The conventional tablet released all drug (Fe +2 ) in acidic medium by the end of the 1 st hour compared with about only 40% of the drug release for hydrophilic matrix tablets at the same time. Also, conventional tablets released all drug in about 4 hours in D.M Water at pH 6 whereas most of the hydrophilic matrix tablets released all the drug by the end of the 17 th hour in D.M Water at pH 6. All the tablets showed slower drug (Fe +2 ) release in acidic medium (pH 4.5) and gives no drug release in dissolution medium pH 6.8. There is no significant difference in drugrelease of hydrophilic matrix tablets if the concentration of polymers HPMC increased whereas the increase in the concentrations of MCC, Starch, or Lactose affect drug (Fe +2 ) release profiles. Release profiles for most of hydrophilic matrix tablets showed a tendency to follow zero order kinetic (Non-fiction - Case II) Analysis with Taguchi experimental method showed that the best combination that gives the least drug release in the acidic medium at the 1 st hour, and required time for 90% of drug release was found to be the one containing 25% HPMC, 5% MCC, 5.46% Starch and 5.46% Lactose out of total tablet weight. The release profile and kinetic ofdrug release were functions of physio-chemical nature of drug (e.g. solubility) and types of selected excipients used. Swelling rate of the matrix tablets and quantity of fluid penetration in the matrix tablets were found to be influenced by the excipients (MCC, Starch, and Lactose). Food has strong influence in drug release profile.