mucoadhesive microspheres

In an endeavor to boost the prophylactic action of Quercetin Dihydrate against mustard agent poisoning, mucoadhesive microspheres, were formulated. The microspheres enclosed Quercetin Dihydrate, an adhesive polymer (ethyl cellulose) and a colon specific polymer (Eutragit S100). Microspheres were devised by an oil/water emulsification solvent evaporation method. Two variables polymer concentration and plasticizer concentration for formulation were used. The mean particle sizes of the prepared microspheres were found significantly increasing with polymer concentration and decreased with increasing plasticizer concentration. The drug entrapment effectiveness increased with increasing plasticizer concentration. The Percentage mucoadhesion increases with increasing concentration of ethyl cellulose but not much affected by concentration of eudragit. Drug entrapment efficiency was found in range of 73.35±2.7 (batch R1) to 80.61±1.54 (batch F5). The entire formulations had excellent flow property. The best fit release kinetic model was found to be Higuchi for all formulations, which indicated release from matrix type formulation. The In vivo studies on male wistar rats were conducted and plasma concentration time method was employed to study the influence of quercetin by formulating it as microspheres. By Statistical Analysis through sigma plot, the semi log plot of pure drug (Quercetin) and its microspheres shows linearity which indicates that they follow linear kinetics. Formulation of microspheres produced a sustained effect on its absorption and availability and several parameters are there which concluded that the microspheres of quercetin are better choice for mustard toxicity as compared to pure drug.

Terbutaline sulphate loaded microspheres were prepared for Nasal administration with the aim of avoiding first pass effect. The microspheres were prepared by a water-in-oil (w/o) emulsification-cross-linking technique by using chitosan as a mucoadhesive polymer, liquid paraffin (heavy and light, ratio 1:1) as a external phase, dioctyl sodium sulfosuccinate (0.2% w/v) as a stabilizer, volume of cross-linking agent (Glutaraldehyde, 25% solution, 1 mL) and time of cross linking 2 hrs. A 23 full factorial design was constructed to study the effect of three independent variables i.e. drug: polymer ratio (X1), volume of cross linking agent (ml) (X2), cross linking time (Hrs)(X3) while Particle size of the microspheres (Y1) and In vitro mucoadhesion (Y2) were taken as response parameters as the dependent variables. Particle size was found to be 26.11 ± 1.98 mm, which is favorable for intranasal absorption. The shape and surface characteristics were determined by scanning electron microscopy (SEM) which depicted the spherical nature and nearly smooth surfaces of the microspheres. The percentage encapsulation efficiency was found to be 74.4 ± 0.604%. In vitro mucoadhesion was performed using sheep nasal mucosa and was observed 72.32 ± 0.25%. FTIR Spectroscopy indicates characteristic peaks of the functional groups present in the drug, Differential scanning calorimetry and X-ray diffraction results indicated a molecular level dispersion of Terbutaline sulphate in the microspheres. In vitro release studies in pH 6.2 phosphate buffer indicated the mechanism of drug release was of zero order.