Physicochemical properties and characterization of nata de coco from local food industries as a source of cellulose (Sifat fizikokimia dan pencirian nata de coco daripada industri makanan tempatan sebagai sumber selulosa)

Nata de coco, a dessert originally from the Philippines is produced by fermentation of coconut water with a culture of Acetobacter xylinum, a gram negative bacterium. Acetobacter xylinum metabolizes glucose in coconut juice and converts it into bacterial cellulose that has unique properties including high purity, crystallinity and mechanical strength. Because the main component of nata de coco is bacterial cellulose, nata de coco was purified, extracted and characterized to determine whether pure cellulose could be isolated from it. The FTIR spectra of bacterial cellulose from nata de coco showed distinguish peaks of 3440 cm-1, 2926 cm-1, 1300 cm-1, 1440 cm-1, 1163 cm-1 and 1040 cm-1, which correspond to O-H stretching, C-H stretching, C-H bending, CH2 bending, C-O-C stretching and C-O stretching, respectively, and represent the fingerprints of pure cellulose component. Moreover, the FTIR curve showed a pattern similar to other bacterial cellulose spectra reported by report. Thermal analysis showed a DTG peak at 342°C, which falls in the range of cellulose degradation peaks (330°C - 370°C). On the other hand, the TGA curve showed 1 step of degradation, and this finding confirmed the purity of nata de coco. Bacterial cellulose powder produced from nata de coco was found to be soluble only in cupriethylenediamine, a well known solvent for cellulose; thus, it was confirmed that nata de coco is a good source of bacterial cellulose. The purity of bacterial cellulose produced from nata de coco renders it suitable for research that uses pure cellulos

Deformation and Mechanical Characteristics of Compacted Binary Mixtures of Plastic (Microcrystalline Cellulose), Elastic (Sodium Starch Glycolate), and Brittle (Lactose Monohydrate) Pharmaceutical Excipients.

This work studies the tensile strength, coherence, elastic, and plastic energy of single and bi-component compacted tablets consisting of (i) microcrystalline cellulose (MCC) PH 102 as a plastic material, (ii) (SSG) as an elastic material, and (iii) alpha lactose monohydrate as a brittle material by direct compression. Compacted tablets were studied with various mass ratios formed at an ultimate compaction stress of 150 MPa. The loading and unloading stages of the compaction process for the single and binary tablets were evaluated based on the energies derived from the force-displacement data obtained. The resulting tablet quality was measured in terms of the tensile strength. Material that exhibit predominantly plastic deformation (MCC) shows a dominant property over elastically deforming sodium starch glycolate (SSG) and brittle (lactose) materials during the loading and unloading stages of the compaction process. In conclusion, the tensile strength of the formed tablets depends directly on the plastic energy and indirectly on the elastic energy and is negatively affected by the presence of a brittle material

Physical properties and in vitro studies of sustained-release ketoprofen matrix tablets

The use of sustained release tablet formulation for non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin has shown its capability to protect the stomach lining from the adverse effect of gastric juice from the body. This study was carried out to evaluate the efficiency of sustained release matrix tablet formulation using ketoprofen as a model drug with different polymers concentration. The tablets were prepared by the wet granulation method using hydrophilic polymer (hydroxypropyl methylcellulose), hydrophobic pH dependent polymer (Eudragit L100-55) and independent polymer (Eudragit RD 100) as matrix forming retarding materials at 10%w/w, 20%w/w and 30%w/w. All formulations were compressed using 10 mm concave faced punches. The compressed tablets were evaluated for uniformity of weight, friability, hardness, thickness, % drug content and in vitro dissolution test with regard to BP 2007. The results showed that the drug release rate was found to be governed by the type and concentration of polymer in the matrix system. Generally, increasing the polymeric concentration in the matrix tablets will decrease the rate of drug release. When the polymers were compared at similar concentration using t50%, the difference in drug release was found to be statistically significant (p<0.05). Based on the in vitro drug dissolution studies, the hydrophobic pH dependent polymer (Eudragit L100-55) showed a better zero drug release profile compared to other polymers

Development of Diabecine™ tablet and confirmation of its physical properties and pharmaceutical safety analysis

Herbal medicine is usually made using dry powdered herbs in the form of capsule. Capsule form herbal supplement suffers lower shelf life as compared to compact herbal powder in tablet form. In this study, Diabecine™, a blend of herbal medicine traditionally used as herbal supplement for diabetic patients was selected and transformed into a compressed tablet. Direct compression method and minimal usage of excipients were the aims of this study. By using direct compression, the blend of 40% fine powder herbs and 60% of excipients performed the best and fulfill the pharmaceutical standard. The safety data of microbial and heavy metal testing obtained met the safety requirements for herbal supplement category under the National Pharmaceutical Control Bureau of Malaysia. In conclusion, the tablet formulation of Diabecine™ is suitable to be manufactured by using direct compression method. This research implicates the possibility of producing tablets with high dose of herbal powder by direct compression method

In Vitro

Mixed micelles of Pluronic F127 and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) in different molar ratios (10 : 0, 7 : 3, 5 : 5, and 3 : 7) were prepared to characterize this system as nanocarriers for targeted delivery of chemotherapeutic agents. Their size, zeta potential, critical micelle concentration, drug loading content, entrapment efficiency, drug release, cytotoxicity, and stability in serum were evaluated in vitro by using doxorubicin as the model anticancer drug. The micellar sizes ranged from 25 to 35 nm. The 7 : 3 and 5 : 5 micellar combinations had lower critical micelle concentrations ( M) than the 10 : 0 combination ( M). The entrapment efficiencies of the 7 : 3, 5 : 5, and 3 : 7 micellar combinations were 72%, 88%, and 69%, respectively. Doxorubicin release was greater at acidic tumour pH than at normal physiological pH. The doxorubicin-loaded mixed micelles showed greater percent inhibition and apoptosis activity in human breast adenocarcinoma (MCF-7) and acute monocytic leukaemia (THP-1) cell lines than free doxorubicin did. The mixed micelles were also stable against aggregation and precipitation in serum. These findings suggest that Pluronic F127-TPGS mixed micelles could be used as nanocarriers for targeted anticancer-drug delivery

PAMAM Dendrimers as Promising Nanocarriers for RNAi Therapeutics

Therapeutics based on RNA interference mechanisms are highly promising for the management of several diseases including multi-drug resistant cancers. However, effective delivery of siRNAs and oligonucleotides still remains challenging. In this regard, hyper-branched, PAMAM dendrimers having unique three-dimensional architecture and nanoscale size, with cationic surface charge can potentially serve as siRNA condensing agents as well as robust nano-vectors for targeted delivery. In addition, their surface functionality permits conjugation of drugs and genes or development of hybrid systems for combination therapy. Thus far, in vitro cellular testing of dendrimer-mediated siRNA delivery has revealed great potential, with reports on their in vivo effectiveness starting to appear. These favorable outcomes portend a promising future for dendrimer mediated RNAi therapeutics

Characterisation and In Vitro Antimicrobial Activity of Biosynthetic Silver-loaded Bacterial Cellulose Hydrogels

Wounds that remain in the inflammatory phase for a prolonged period of time are likely to be colonised and infected by a range of commensal and pathogenic microorganisms. Treatment associated with these types of wounds mainly focuses on controlling infection and providing an optimum environment capable of facilitating re-epithelialisation, thus promoting wound healing. Hydrogels have attracted vast interest as moist wound-responsive dressing materials. In the current study, biosynthetic bacterial cellulose hydrogels synthesised by Gluconacetobacter xylinus and subsequently loaded with silver were characterised and investigated for their antimicrobial activity against two representative wound infecting pathogens, namely S. aureus and P. aeruginosa. Silver nitrate and silver zeolite provided the source of silver and loading parameters were optimised based on experimental findings. The results indicate that both AgNO3 and AgZ loaded biosynthetic hydrogels possess antimicrobial activity (p < .05) against both S. aureus and P. aeruginosa and may therefore be suitable for wound management applications