Physico-chemical aspects of modified biomaterial of Tympanotonus fuscata (periwinkle) shell powder considered as pharmaceutical excipient

Abstract

A modified biomaterial based novel pharmaceutical excipient was developed from Tympanotonus fuscata (periwinkle) shell and characterized. A 100 g quantity of milled shell was digested in 166 ml of 2 M HCl, filtered and neutralized with 5 M NaOH yielding a precipitate. It was washed severally with deionized water. Ortho-phosphoric acid was added drop wise to its thick aqueous suspension until a thick, dehydrated mass formed. This was dried at 60 ^o C and classified with 250 μm sieve to obtain a modified biomaterial powder of periwinkle shell (MBPPS). It was tested for calcium and phosphate compound, solubility, pH, moisture absorption, acute toxicity, elemental content, drug compatibility, ash values, densities, flow parameters, etc. A non-toxic (LD₅₀ 15,000 mg / kg body) tasteless, odourless and white powder testing positive for calcium and phosphate compound was obtained. Melting temperature was 190.8^oC. It was compatible with a range of drugs and was soluble in dilute HCl and HNO₃ but practically insoluble in cold water and organic solvents. A 10 % w/v aqueous dispersion of it has pH of 7.57. Lead, silver, cadmium, nickel, vanadium, mercury or barium were not detected. Iron and some other heavy metals within the Pharmacopoeia acceptable limit were detected. Moisture content was 2.28 ± 0.01%. It absorbed 6.98 ± 0.15, 9.08 ± 0.28 & 11.00 ± 0.87 moisture in relative humidity of 96, 84, 75 and 52% at 30 ^o C respectively. A total ash of 88.00 ± 1.30%, acid insoluble ash, 0.6 ± 0.24 % and water soluble ash, 0.5 ± 0.06 % was obtained. Considering the high production yield of MBPPS, its non-toxicity, compatibility with a range of drugs, and hardness above 12N of its compact, it may serve as a good material for direct compression of tablets especially for low dose drugs.

Keywords: Physicochemical, modified, biomaterial, Tympanotonus fuscata, periwinkle shell