microspheres

Gout is a disease caused by the deposition of monosodium urate (MSU) crystals in tissue such as cartilage, synovial membranes, bones and skin which causes inflammation in the synovial tissue. Indomethacin is first line of drug used as NSAID for the treatment of Gout. The aim of this study was to encapsulate Indomethacin in ethyl cellulose microspheres and compare the efficiency of the formulated Indomethacin microspheres with the Marketed formulation. Indomethacin microspheres were prepared by solvent evaporation method. FTIR  studies revealed there was no significant interaction between the drug and polymer. Preformulation studies gave satisfactory results. SEM studies showed a spherical smooth microsphere average size of 10.4±3.04. The percentage entrapment efficiency and percentage drug release after 10 hours was found to be 82.97±1.6 % and 52.04±0.58 % respectively. The therapeutic effect of the Indomethacin microspheres was evaluated by the swelling of knee joints, joint range of motion and histologic analysis of MSU induced rat model. The prepared indomethacin microspheres showed effective prolong in the retention time of the drug in the intra articular cavity to 30 d which is more than that of the marketed formulation. Intra- articular injection of Indomethacin microspheres efficiently relieved inflammatory symptoms such as swelling index, joint range motion and suppressed inflammatory cell infiltration than the marketed formulation. Thus intra-articular injection of Indomethacin loaded microspheres proved to be a promising therapeutic method in the treatment of Gout.

In the present investigation efforts were made to develop Misoprostal loaded microspheres to obtain a desirable drug release profile by Ionic gelation method using hydrophilic polymers and cross linking agent to decrease the gastric irritation and to enhance the drug penetration. Microspheres were prepared by using sodium alginate and calcium chloride in different ratios.  All the microspheres were evaluated for particle size, percentage yield, drug entrapment efficiency, stability studies and for in vitro release kinetics and found to be within the limits. Among all the formulations S7 was selected as optimized formulation based on the physico chemical properties and drug release studies. In vitro drug release study of formulation S7 showed 97.17% drug release up to 12h in a controlled manner, which is essential for an anti ulcer therapy. The innovator Misoprostal marketed product shows the drug release of 95.23 in 1 h. The drug release of optimized formulation S7 followed zero order release and Higuchi kinetics indicating diffusion controlled drug release. FT- IR study showed no drug excipient interaction takes place.

Present study aims to prepare and evaluate Metoprolol succinate microspheres by ionotropic gelation method. Among all the formulations S7 was selected as optimized formulations for based on the physico chemical parameters and drug release studies. In the in vitro release study of formulation S7 showed 96.29% after 12 h in a controlled manner, which is essential for disease like peptic ulcer. The in vitro release profiles from optimized formulations were applied on various kinetic models. The best fit with the highest correlation coefficient was observed in Higuchi model, indicating diffusion controlled principle. FT-IR and DSC analyses confirmed the absence of drug-polymer interaction. The results obtained from evaluation and performance study of different types of Metoprolol succinate microspheres that system may be useful to achieve a controlled drug release profile suitable for peroral administration and may help to reduce the dose of drug, dosing frequency and improve patient compliance when compared with marketed product.

Gemifloxacin mesylate loaded microspheres were prepared by Ionotropic gelation technique with different drug to carrier ratio. All the microspheres were characterized for particle size, scanning electron microscopy, FTIR study, DSC, percentage yield, drug entrapment, stability studies and for in vitro release kinetics and found to be within the limits. Among all the formulations S8, was selected as optimized formulation based on the physic chemical and release studies. In the in vitro release study of formulation S8 showed 95.92%, after 12 h in a controlled manner, which is essential for anti ulcer therapy. The innovator Gemiflox conventional tablet shows the drug release of 95.23% within 1 h. The drug release of optimized formulation S8 followed zero order and Higuchi kinetics indicating diffusion controlled drug release.

Gastroretention is advisable for metformin hydrochloride due to its site specific absorption and low bioavailability (60%). Therefore, the attempts have been carried out in present study to formulate bioadhesive microspheres of metformin hydrochloride. Microspheres provide precise control on drug release and bioadhesion is useful to obtain gastroretention for improvement in bioavailability. Drug loaded microspheres of bioadhesive polymers were prepared by ionic gelation method. Hydroxypropyl methyl cellulose (HPMC), hydroxypropyl cellulose (HPC) and methyl cellulose (MC) were used as bioadhesive polymers. Microspheres were prepared by using various ratios of sodium alginate to respective polymer(s). One gram of drug was added in 50ml solution of polymers separately. Microspheres were collected in 10% w/v calcium chloride solution with constant stirring. Formulation MS2 (sodium alginate: HPC; 1:1) was found to be the best among all. For MS2, percent yield (65.5%), drug entrapment efficiency (72±0.56%), particle size (851 µm), in vitro wash off test (63.9 %), in vitro drug release (80.77 %) etc. Some process parameters viz orifice diameter of needle used to pass polymer solution, dropping height and stirring speed were studied. It was observed that as the orifice diameter of needle decreased from needle no. 18 to 23, the microspheres were more spherical with retention in their shape and needle no. 20 was found to be optimum. More spherical microspheres were observed with decrease in dropping height and optimum was found to be 6 cm. With increase in stirring speed from 250 to 750 RPM, drug entrapment efficiency decreased. 

The present work is aimed at formulation and evaluation of floating drug delivery system of nateglinide for the management of diabetes. Hollow microspheres (microballoons), loaded with nateglinide in their outer polymer shells were prepared by using emulsion solvent diffusion method. The prepared formulations were evaluated for their surface morphology by scanning electron microscopy (SEM), micromeretic properties, % drug entrapment efficiency, % buoyancy and in-vitro drug release studies. The prepared microspheres exhibited prolonged drug release (24 h) and remained buoyant for >12 h. The mean particle size increased and the drug release rate decreased at higher polymer concentrations. No significant effect of the stirring rate during preparation on drug release was observed. The release pattern of nateglinide in simulated gastric fluid from all floating microspheres showed their sustained action.

The major problems associated with the anti-tubercular (TB) drug therapy include loss of efficacy through bacterial resistance, side effects, low patient compliance and duration and complexity of treatment. The present study attempts to confront them through a combined approach consisting of microspheres and bioenhancers. Microspheres containing rifampicin were prepared by emulsification technique using stearic acid as a cross-linking agent. Extract of Carum carvi were added as a bioenhancer in variable amount of 5 to 15 mg for each dose of rifampicin. The loading efficiency and release behavior of loaded microparticles were found to be dependent on the cross-linker concentration, cross-linking time and drug-polymer ratio. Prolonged release of the drug from the microspheres was demonstrated in a simulated intestinal fluid. In-vitro release of rifampicin from the microspheres containing 15 mg of bioenhancer showed significant increase in release profile (87.42% in formulation containing bioenhancer against 51.41% for the formulation without bioenhancer) and the release rates were reduced upon increasing the amount of cross-liking agent and prolonging the cross-linking time.