Comparative evaluation of hydrolytic efficiency toward microcrystalline cellulose of Penicillium and Trichoderma cellulases

1995 ◽  
Vol 52 (2) ◽  
pp. 119-124 ◽  
Author(s):  
O.F. Castellanos ◽  
A.P. Sinitsyn ◽  
E.Yu. Vlasenko
2020 ◽  
Vol 16 (1) ◽  
pp. 31-37
Author(s):  
S.O. Eraga ◽  
D.N. Elue ◽  
M.A. Iwuagwu

Background: Natural materials have gained a lot of significance in the field of drug delivery because of their cost effectiveness and ready availability.Purpose: The study aimed at evaluating the direct compression property of microcrystalline cellulose from cassava fermentation waste in directly compressed paracetamol tablet formulations.Methods: Alkali delignification of the dried cassava fermentation fibres, followed by bleaching and acid depolymerisation was employed in the extraction of α-cellulose and conversion to microcrystalline cellulose (MCC). The MCC obtained and Avicel® were used at different concentrations (5.0-15 %w/w) to formulate batches of paracetamol tablets by directed compression. A comparative evaluation of the formulated paracetamol granules and tablets properties were undertaken.Results: The paracetamol granules formulated showed good flowability with Hausner’s ratios of 1.15-1.25, Carr’s indices of 13.10-20.00 % and angles of repose ≤ 34.41°. The formulated tablets showed good hardness (> 5.0 kgf) and disintegration time within 10 min. Only tablets containing 5.0 and 7.5 %w/w of the test MCC failed the BP dissolution test specification for tablets which stipulates that at least 70 % of the drug should be in solution after 30 min.Conclusion: This study has shown that the extracted MCC has direct compression ability evidenced in the mechanical strength of the formulated paracetamol tablets. The tablet properties of the formulated paracetamol tablets revealed pharmaceutically acceptable tablets though they were not comparable with Avicel® at all concentrations and the MCC may serve as an alternative local source for direct compression excipient. Keywords: Cassava, microcrystalline cellulose, direct compression, paracetamol, tablets


1986 ◽  
Vol 51 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Donna M. Risberg ◽  
Robyn M. Cox

A custom in-the-ear (ITE) hearing aid fitting was compared to two over-the-ear (OTE) hearing aid fittings for each of 9 subjects with mild to moderately severe hearing losses. Speech intelligibility via the three instruments was compared using the Speech Intelligibility Rating (SIR) test. The relationship between functional gain and coupler gain was compared for the ITE and the higher rated OTE instruments. The difference in input received at the microphone locations of the two types of hearing aids was measured for 10 different subjects and compared to the functional gain data. It was concluded that (a) for persons with mild to moderately severe hearing losses, appropriately adjusted custom ITE fittings typically yield speech intelligibility that is equal to the better OTE fitting identified in a comparative evaluation; and (b) gain prescriptions for ITE hearing aids should be adjusted to account for the high-frequency emphasis associated with in-the-concha microphone placement.


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