Characterization and chemical modification of cellulose from some selected local varieties of Oryza sativa chaff in Northern Nigeria

Abstract

Background: This study was targeted at extracting and production of microcrystalline cellulose from some local varieties of rice chaff being one of the most versatile excipient use in pharmaceutical tableting.    Methods: Microcrystalline cellulose was derived from locally sourced rice chaffs in Taraba, Kano, Kaduna, and Kogi-Nigeria by standard extraction procedures from literature with modifications. Ethanol (95 %) was utilized in solvent extraction for 6 h to remove wax and resins leaving the fibrous material. Alkaline hydrolysis with 17.5 % NaOH was employed to remove hemicelluloses leaving αcellulose with lignin followed by exposure to 200 mL of glacial acetic acid to neutralize excess of the alkali. This was then delignified and bleached by treatment with sodium hypochlorite solution. The α-cellulose was modified to microcrystalline cellulose by mineral acid (HCL) at 1050c for 15 mins leaving microcrystalline cellulose after washing with water. The final isolated product was characterized using Fourier Transform Infrared Spectroscopy (FTIR).   Results: The microcrystalline cellulose content of the four rice chaffs was 18, 15, 21, 11 % respectively. This compares reasonably with the findings of other previous studies, vis. 19 % for Oryza sativa sippi. From the extraction sets of studies, Oryza sativa sippi gave the highest content of microcrystalline cellulose. Fourier Transform Infra-red (FT-IR) spectra confirm the presence of characteristic functional groups and indicate the purity of the sample. Melting was observed at temperature 249⁰C, 231⁰C, 244⁰C, 203⁰C and 255⁰C with samples A, B, C, D and the reference respectively.    Conclusions: This study demonstrates that the geographical origin of the materials significantly influences their potential yields and may contribute to variations in specific physicochemical properties.