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Microencapsulated gelospheres were prepared using the water swellable polymers, poly(vinyl alcohol) and polyacrylamide in which the drug was embedded. Polymeric coating was formed by interfacial polymerization using 1, 6 hexamine and sebacoyl chloride. The size, shape, in vitro release, kinetics and in vivo efficiency of the formulation were determined. The shape was found to be spherical with a size range below 100μm. The per cent drug loaded was found to be higher in the case of gelospheres prepared with polyacrylamide than those prepared with poly(vinyl alcohol). The release rate was found to be near zero order. The AUC was found to be higher in the case of polyacrylamide and polyvinyl alcohol gelospheres as compared to plain drug solution. [ABSTRACT FROM AUTHOR]

Aim: The present study was conducted to formulate and investigate liposomes for the dual drug delivery based on anti-tubercular drug(s) combination i.e. Isoniazid (INH) and Rifampicin (RIF)., Materials and Methods: Mannosylated and non mannosylated liposomes were prepared by lipid thin film hydration method, using DSPC: Chol at a molar ratio 6:4 while in case of mannosylated liposomes DSPC: Chol: Man-C4-Chol at a molar ratio 6.0:3.5:0.5 were used and extensively characterised. The particle size and zeta potential were recorded to be 1.29 ± 0.24 µm and -9.1 ± 0.11 mV. The drug entrapment (%) was recorded to be 84.7 ± 1.25% for Rifampicin and 31.8 ± 0.12% for Isoniazid., Results: The antitubercular activity studied in Balb/C mice was maximum in the case of mannosylated liposomes. The biodistribution studies also revealed higher drug(s) concentration (accumulation) maintained over a protracted period., Conclusions: The liposomal preparations are passively as well as actively uptaken by the alveolar macrophages which are the cellular tropics of infection. The mannosylated liposomes appear to be a potential carrier for dual drug delivery and targeted antitubercular therapy.

Indomethacin, a non-steroidal anti-inflammatory drug was successfully entrapped into liposomes (soyabean lecithin, cholesterol, stearylamine or dicetylphosphate) with uniform size distribution. The liposomal vesicles were derived from dried effervescent granule-based proliposomes. The in vivo distribution characteristics of the reconstituted liposomal indomethacin was studied in normal rats and in the rats with inflamed paws following intravenous administration. The localization of the liposome-based indomethacin was in liver, lungs and inflamed tissues (inflamed rats studies). Further, an enhanced anti-inflammatory activity of lipo-indomethacin was found as compared with the activity recorded for plain drug in carrageenan induced paw oedema in rats.

The pseudolatex-based ocular formulations of pilocarpine were prepared using different combinations of Eudragit RS 100 and polyvinyl pyrrolidone for prolonged and controlled release of the drug. The designed system was essentially based on polymeric pseudolatex dispersion. The process variables that effect the latex particle size, drug loading and release profiles of drug were studied. Preparations were evaluated for their in vitro performance with regard to release profile and diffusion co-efficient. The designed system exhibited linear relationship between cumulative drug release (Q) and square root of time (t0.5). The products selected on the basis of in vitro characterization were studied for in vivo performance evaluation. It was observed that the preparations exhibited in vivo prolonged therapeutic efficacy. Thus polymer based pseudolatices hold promise for controlled pilocarpine ocular delivery.

Human serum albumin microspheres containing neomycin sulphate were prepared using emulsion polymerization and polymer dispersion techniques. The many variables which may affect the shape, size, stability, release of the drug from the microspheres such as internal phase to external phase volume ratio, human serum albumin content, stirring rate, polymer content and stabilizing agent concentration, were studied. Unlike the microspheres prepared by the emulsion polymerization technique, polymer dispersion stabilised microspheres were uniform in size and shape with a narrow range of size distribution. In vitro release of neomycin sulphate from albumin microspheres was studied using the dialysis cell method. The drug release from microspheres followed Q versus (t)-1/2 linear relationship. The in vivo distribution studies on prepared microspheres revealed that the localization takes place preferably in lung tissues, liver, spleen and kidney and is found to be dependent on the microsphere size. On administration of microspheres of 3-6 microns size, approximately 55 per cent of administered drug could be localized in the lungs.

The in vivo magnet responsiveness and kinetics of distribution of indomethacin entrapped in a magnetic and plain carrier were characterized by rat tail model and periodic monitoring of drug concentration in various visceral organs after intraarterial and intravenous administration respectively. Up to 60 min post injection time 60-fold higher concentrations could be achieved in tail target segment which resulted in considerably reduced drug concentration in other organs as evinced by data from control rats. Following normal administration (no magnetic field applied) the drug concentration was higher in the liver and spleen where endocytosis and phagocytosis occur. The magnetic nanoparticle of indomethacin holds promise for selective targeting under magnetic field of 8000 Oe strength.