PHYSICOCHEMICAL AND PHARMACEUTICAL CHARACTERISATION OF MUCILAGE FROM SWEET BASIL SEED

Objective: Gums and mucilages are of immense significance as excipients owing to their renewable natural sources, cheapness, ready availability, biodegradability, non-toxicity, ability to undergo hydration and swelling rapidly. To satisfy the ever-increasing demand for highly specific and functional excipients, sweet basil (Ocimum basilicum L.) has been selected for the purpose of isolation of mucilage from its seeds and its physicochemical and pharmaceutical characterisation. Methods: Physicochemical characterisation of sweet basil seed mucilage was carried out by FTIR spectroscopy, HPTLC, phytochemical tests, X-ray diffractometry, studies on mucilage hydration, water holding capacity and swelling behaviour. Determination of compressibility index, Hausner ratio and angle of repose was done as part of pharmaceutical characterisation of mucilage. Results: The geometric diameter, sphericity and surface area of the seed have been found to be 1.24±0.31 mm, 0.62±0.01 and 4.83±0.5 mm2 respectively. From microscopy, mucilage from seeds was seen to emerge as spiral filaments as soon as they were placed in water. The FTIR study reveals the mucilage to be a carbohydrate containing–OH groups with intermolecular hydrogen bonding as in polysaccharides, with 1→4 glycosidic bonds. Qualitative phytochemical screening of Ocimum basilicum L. seed mucilage (BSM) revealed the presence of non-reducing sugars, gums and mucilage. X-ray diffractogram presented its amorphous structure. The HPTLC profiles of BSM in n-butanol: acetic acid: water (4:1:1) at 254 nm and at 366 nm (before and after spraying with p-anisidine) revealed several bands with Rf values ranging from<0.1 to 0.5. The water-holding capacity of the mucilage has been found to be 97.5±2.4 g/g mucilage and swelling index values (0.1-0.5% w/v) were in the range of 100±10 to 200±13 at 25 °C. BSM was found to possess fair to passable flow property with Hausner’s ratio of 1.247 and angle of repose of 37.57°. Conclusion: Therefore, mucilage from sweet basil seed can be employed as an excipient in manufacture of tablets by wet granulation after addition of suitable lubricants and also in development of liquid dosage forms.