Prednisolone Loaded Tamarind Gum Microspheres for Colonic Delivery

The aim of this work was to formulate a novel multiparticulate system having pH sensitive property and specific enzyme biodegradability for colon specific drug delivery of Prednisolone (PD). Natural polysaccharide, Tamarind gum is used for microsphere preparation and Eudratit S- 100 for coating to provide pH controlled drug release. The formulation aims at minimal degradation and optimum delivery of the drug with relatively higher local concentration, which may provide more effective therapy for inflammatory bowel disease including Crohn disease and ulcerative colitis. Tamarind gum microspheres were prepared by emulsion dehydration technique using polymer in ratio of 1:1 to 1: 9. These microspheres were coated with Eudragit S-100 by oil in oil solvent evaporation method using core: coat ration (5:1). Tamarind gum microspheres and Eudragit coated tamarind gum microspheres were evaluated for surface morphology, particle size and size distribution, percentage drug entrapment, surface accumulation studies, in vitro drug release in simulated gastrointestinal fluids. The effect of various formulation variables were studied the prepared microspheres were spherical in shape in the size range of 64 µm to 113 µm, the encapsulation efficiency was in range of 30-72% depending upon the concentration of gum. The drug release was about 14-20% in first four hours of study gradually rises in 5th hour and 85% drug release occurs in 10-12% hr thus showing desirable drug release in the colonic simulated environment. PD tamarind gum microspheres are thought to have the potential to maintain drug concentration within target ranges for a long time, decreasing the side effects caused by concentration fluctuation, ensuring the efficiency of treatment and improving patient compliance by reducing dosing frequency. The animal study done using acetic acid induced colitis model on rats also suggest the anti inflammatory activity of the formulation.

DOPO-Modified Cellulose Microsphere: Preparation and Application for Selective Adsorption U(VI) under Acidic Solutions

Effective radioactive wastewater disposal is of great significance to the wide use of nuclear energy. In this work, 4, 4ˊ-[1, 4-phenyl-bis (9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl) dimethyneimino)] diphenol (t-DOPO) was used to modify microcrystalline cellulose microsphere (t-DOPOR) to further enhance it affinity toward U(VI) through radiation method. The t-DOPOR were characterized for structural, morphological, and thermal properties by FTIR, SEM and TGA, which prove that t-DOPO is successfully modified on cellulose. Combination the advantage of cellulose and t-DOPO, t-DOPOR possessed abundant functional group (-OH, -NH and P=O), and exhibited extremely strong affinity toward U(VI) with a maximum adsorption capacity of 51.51 mg/g at pH 3. Particularly, A large distribution, KdU, up to 2.54×104 mL g−1 is found, implying extremely strong affinity toward U(VI) than Ln(III) (La(III), Eu(III), Dy(III), Yb(III)) at the binary system. Dynamic column experiment confirmed that t-DOPOR could separate selectively U(VI) in column experiment. In addition, even in the simulated groundwater trace amount of U(VI) was also eliminated efficiently by t-DOPOR. Lastly, the adsorption mechanism elaborated by XPS analysis was inner-sphere surface complexation between U(VI) and -OH, -NH and P=O groups of t-DOPOR. Overall, the synthesized t-DOPOR may be utilized as a promising adsorbent for separation and remediation of U(VI) from wastewater.

Design and Optimization of Novel Vaginal Microsphere Gel of Clotrimazole

The objective of the study was to develop and evaluate sustained release microsphere gel for the drug clotrimazole to be administered through the vaginal route. The effect of polymer ethylcellulose and carbopol 934 on entrapment efficiency and diffusion behavior were investigated respectively. A 32 full-factorial design was used to optimize the formulation of Microsphere gel. Microspheres were characterized by SEM, FTIR, Entrapment efficiency, and particle size. Gels were evaluated for in-vitro drug release in simulated vaginal fluid. The microsphere loaded with clotrimazole in bioadhesive carbopol gel formulation was evaluated for various physicochemical studies and was found to be satisfactory. The rheological profile shows the gel formation at desired condition. It is evaluated for spreadability, drug content, In-vitro drug diffusion, stability study, and bioadhesive study. It may be concluded that spray drying is a suitable method for microsphere preparation and microsphere gel can be used as a novel drug delivery system to prolonge release of clotrimazole for vaginal candidiasis.

Comparison Ability of Polymers Acrycoat S100 And HPMC K4M to Entrapment Efficiency Domperidone in Microspheres

Domperidone is a prokinetic and antiemetic agent which has low bioavaibility. To increase the bioavaibility of drug, it can be modified into microsphere that can hold drug more longer in gastric to improve the bioavaibility. The microsphere preparation requires a polymer that can make matrix system to protect and deliver the drugs. Acrycoat S100 and HPMC K4M are the usual polymers that used for encapsulation and have biodegradable characteristic. The aim of this research is to know the comparison ability of two different polymers to entrapment the drug in microsphere. Microsphere domperidone made by solvent evaporation method in 6 formula. F1, F2 and F3 using 50 mg, 100 mg and 150 mg Acrycoat S100 polymer, while F4, F5 and F6 using 50 mg, 100 mg and 150 mg HPMC K4m polymer. The tests were conducted by the determination of the percentage of entrapment efficiency using UV spectrophotometer and evaluation of organoleptic, particle measurement and surface microsphere morphology. The results showed that F3 with Acrycoat S100 polymer has a greater entrapment efficiency of 78,712% ± 4,260% compared to the highest percentage efficiency of HPMC K4M polymer of 4,734±0,390.Key words: Acrycoat S100, domperidone, entrapment efficiency, HPMC K4M, microsphere

From hollow lignin microsphere preparation to simultaneous preparation of urea encapsulation for controlled release using industrial kraft lignin via slow and exhaustive acetone-water evaporation

Lignin nano/microparticles have recently attracted growing interest for various value-additive applications of lignin, especially encapsulation. In this study, in order to establish a highly efficient and highly productive preparation process to effectively utilize technical lignin, a brand-new, slow and exhaustive solution evaporation process following a simple, self-assembly principle was developed using industrial softwood kraft lignin (SKL) from a starting acetone-water (80/20, v/v) solution to recover 100% of the lignin as homogeneous and well-shaped microspheres. The prepared microspheres had a typical average diameter of 0.81 ± 0.15 μm and were hollow with very thin shells (of nanoscale thickness). Based on this developed technique, encapsulation of urea by these lignin microspheres was directly achieved using the same process as hollow lignin microspheres with urea attached to the outside and entrapped inside of the wall. Two distinct urea release rates were observed for the urea-encapsulated microspheres: a fast release of the urea outside the shell wall and a slow (controlled) release of the urea inside the shell wall. The encapsulation efficiency was as high as 46% of the trapped urea as encapsulated inside the lignin microspheres. The slow and exhaustive solution evaporation procedure reported here is a simple and straightforward method for the valorization of industrial kraft lignin as hollow microspheres with controllable, homogeneous and desired morphologies, and especially for the direct preparation of lignin-based encapsulating fertilizers for controlled release.

Recent Advance in Polymer Based Microspheric Systems for Controlled Protein and Peptide Delivery

Sustained-release systems made by biodegradable polymers for protein and peptide drug delivery have received considerable attention by academic researchers and major pharmaceutical companies around the world. Various types of biodegradable materials, including natural and synthetic polymers, have been applied to form protein and peptide drug carriers. Among these material candidates, poly lactic acid (PLA) and poly lactic-co-glycolic acid (PLGA) are the most commonly used biodegradable materials in the development of protein and peptide microspheres. In addition, many microsphere preparation technologies, including spray drying, coacervation, multiple emulsion solvent evaporation method and microporous membrane emulsification have been developed for microspheres preparation. In this review, we particularly summarize and briefly introduce the materials and methods that are used to fabricate microspheres as protein delivery systems. The existing opportunities and challenges for successful protein delivery are also discussed.