FORMULATION ANDCHARACTERIZATION OF OLANZEPINELOADED MUCOADHESIVE MICROSPHERES

Objective: The objective of this research was to formulate and evaluate olanzapine (OLE) mucoadhesive microsphere prepared using carbopol and sodium combination. OLE having extensive hepatic first pass metabolism and low bioavailability problem, determined the need for the development of sustained release formulation.Methods: OLE mucoadhesive microspheres were prepared by ionic gelation method. OLE mucoadhesive microspheres were prepared by ionic gelation method by using calcium chloride as crosslinking agent. The OLE mucoadhesive microsphere was characterized by particle size measurement, process yield, morphology of microsphere, drug entrapment efficiency, mucoadhesion test, differential scanning calorimetry, powder X-ray diffraction, Fourier transforms infrared (FTIR) study and in-vitro drug release.Results: The OLE mucoadhesive microsphere having mean particle size ranged from 546.0 µm to 554.3 µm, and the entrapment efficiencies ranged from 73% to 96%. All the olanzapine (OLE) microsphere batches showed good in-vitro mucoadhesive property ranging from 75.89% to 96.47% and in the in-vitro wash off test ranging from 68.12% to 81.3%. FTIR studies indicated the no drug-polymer interactions in the ideal formulation F9. Therewere no compatibility issues, and the crystallinity of OLE was found to be reduced shoeing less intense peak in prepared mucoadhesive microspheres, which were confirmed by differential scanning calorimeter and X-ray diffraction studies. Among different formulations, the OLE microspheres of batch F9 had shown the optimum percent drug entrapment of microspheres. Release pattern of OLE from F9 microspheres batch followed Higuchi kinetic model. Stability studies were carried out for F9 formulation at 4°C/ambient, 25±2°C/60±5%, 40±2°C/75±5% relative humidity revealed that the drug entrapment, mucoadhesive behavior, and drug release were within permissible limits.Conclusion: The results obtained in this work demonstrate the use of carbopol and sodium alginate polymer for preparation of mucoadhesive microsphere.Keywords: Ionic gelation method, Gastroretentive delivery, Mucoadhesive microsphere, Carbopol

FORMULATION AND EVALUATION OF GLICLAZIDE NANOSPONGES

Objective: The objective of the present study was to develop and characterize an optimal stable nanosponges of Gliclazide (GLZ) by using the emulsion solvent diffusion method and aimed to increase its bioavailability and release the drug in sustained and controlled manner. Methods: The GLZ nanosponge was prepared by emulsion solvent diffusion method using different drug-polymer ratios (1:1 to 1:5) Eudragit S100 is used as a polymer. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) estimated the compatibility of GLZ with polymer. All formulations evaluated for production yield, entrapment efficiency, in vitro drug release, scanning electron microscopy (SEM) and stability studies. Results: The DSC and FTIR Studies revealed that no interaction between drug and polymer. The Production yield of all batches in the range of 73.8±0.30 to 85.6±0.32. Batch F3 showed the highest production yield, the entrapment efficiency of batch F3 70.6±0.77. The average particle size ranges from 303±2.36 to 680±2.50 nm. By the end of 10th hour F3 formulation shown highest drug release was found to be 94.40±1.12%. The release kinetics of the optimized formulation shows zero-order drug release. The stability study indicates no significant change in the in vitro dissolution profile of optimized formulation. Conclusion: The results of various evaluation parameters, revealed that GLZ nanosponges would be possible alternative delivery systems to conventional formulation to improve its bioavailability, the emulsion solvent diffusion method is best method for preparation of nanosponges and release the drug in sustained and controlled manner

A Review on Gastro-Retentive Floating Microspheres

The floating microsphere's purpose is to improve gastric retention time. Floating drug delivery systems are lower in bulk thickness than gastric juice and remain floating on gastric juice for a long period of time without impacting the gastric-emptying rate and increasing bioavailability. Gastro-retentive microspheres are particularly suitable for the continuous or late release of oral formulations with blending versatility to achieve various release patterns, low dose risk as a reproducible and short gastric retention time. The aim of this review is to address literature on the floating device, techniques, selection of suitable or inappropriate drug candidates for GRDDS, low density polymers used to swim over gastric fluid, processes, and floating microsphere assessment and application. Keywords: GRDDS, Floating system, Approaches, Polymer, Mechanism, Method

Hydrodynamically Balanced System: A Review

The most suitable drug delivery route is oral delivery due to its easily administration, patient adherence/ patient capacitance etc. Several approaches have been made for maximizing the G.R.T such as high-density system, floating system, swelling & expanding system and mucoadhesive & bio adhesive system etc. the main motive of reviewing the article is to focus on the mechanism of HBS system, classification with new system such as raft forming system and hollow microsphere, its application, marketed preparation and evaluation study. The procedure of gastric emptying is a complex and may leads to uncertainty for in vivo performance of the DDS. To prevent this type of complex formation and uncertainty, hard work has been done to expand the retention time of DDS for half of the day. The FDDS are beneficial in such process. Keywords: HBS system, GRDDS, gastric residence time (G.R.T), raft forming systems, floating formulations, evaluation study.&nbsp

A Review on Solubility Enhancement by Solid Dispersion Method

The issues of solubility for the targeted drug delivery of the new drug affects, the delivery many existing drug. The minimum 40% of the novel drug from the pharmaceutical industries are showing poor ability of solubilization in water. Hence to increase the solubility of such drug in waters and to increase their bioavailabilities are the major challenges to the scientists. So to overcome such problems and increase dissolution, development of solid dispersion with carriers having good water solubility is beneficiary. Hence solid dispersion methods are found to be an effective method to develop the solubility factor of the drug which showing poor solubility in water. The review highlights the various aspect of solid dispersion type, rational, advantages, limitation and manufacturing processes for the limited commercialization of solid dispersion. Keywords: Solid dispersions, hydrophilic, carrier, solubility, polymer, bioavailability

A stacked record of relative geomagnetic paleointensity for the past 270 kyr from the western continental rise of the Antarctic Peninsula

Paleomagnetic and rock magnetic investigations were carried out on four gravity cores recovered from the western continental rise of the Antarctic Peninsula during the SEDANO II cruise of RV OGS-Explora. The studied cores, each about 6.5 m-long, were collected at a depth of 3700–4100 m below the sea level, on the distal gentle side of sediment Drift 7, and consist of very fine-grained sediments spanning through various glacial–interglacial cycles. Detailed analysis of the paleomagnetic and rock magnetic data allowed to reconstruct relative paleointensity (RPI) records (NRM20 mT/ARM20 mT) for each core.We established a refined age model for the studied sequences by correlating individual SEDANO RPI curves to the global RPI stack SINT-800 [Y. Guyodo, J.-P. Valet, Global changes in intensity of the Earth's magnetic field during the past 800 kyr, Nature 399 (1999) 249–252]. The individual normalized SEDANO RPI records are in mutual close agreement; they were thus merged in a RPI stacking curve spanning the last 270 kyr and showing a low standard deviation. This study also points out that RPI records may provide a viable tool to date otherwise difficult-to-date sedimentary sequences, such as those deposited along peri-Antarctic margins. The new RPI chronology indicates that the sampled sedimentary sequence is younger than previously thought and allows a new high-resolution correlation to oxygen isotope stages. Furthermore, we recognized variations in the rock magnetic parameters that appear to be climatically-driven, with changes in the relative proportion of two magnetic mineral populations with distinct coercivities. Rock magnetic and lithological trends observed in the SEDANO cores indicate that during the climatic cycles of the Late Pleistocene this sector of the peri-Antarctic margin was subjected to subtle, yet identifiable, environmental changes, confirming a relatively higher instability of theWest Antarctic ice sheet with respect to the East Antarctic counterpart