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Objective: To develop and evaluate the mucoadhesive microsphere using combinations of natural polymers chitosan and xanthan gum for sustained release. Methods: In the present work mucoadhesive microspheres were prepared by using natural polymers like chitosan and xanthan gum by using the emulsion chemical cross-linking method. Chemical cross-linking was done by using glutaraldehyde. The 22 factorial design was employed to show the effect of cross-linking agent and processing factor-like stirring and speed. Prepared microspheres were evaluated for their particle size, surface morphology, drug entrapment efficiency, in vitro drug release, swelling index, and mucoadhesive strength. Results: The size of microspheres of factorial batches were in the range of 26-46 µm. The swelling index was showed in the range of 1.51-1.66 percentage. The equation of multiple regression revealed that there was significant interaction among factors. The glutaraldehyde concentration had a positive effect on % entrapment efficiency, % cumulative drug release and % mucoadhesion. Stirring speed showed a negative impact on % entrapment efficiency, % cumulative drug release and % mucoadhesion. The interactive effect of glutaraldehyde concentration and the stirring speed was found to be positive for % entrapment efficiency and % cumulative drug release. In vitro drug release study of optimized formulation F2 show 96 % of drug release with 6 h indicating sustained release behavior with diffusion mechanism. The SEM image of the optimized batch was spherical with a porous surface. Conclusion: The results obtained in this research work indicated that a promising potential of chitosan and xanthan gum combination for the preparation of the mucoadhesive microsphere of Racecadotril.
RESUMO
Purpose: To report clinical manifestations of ocular allergy to atropine eye drops used for retardation of progressive myopia in children. Methods: Myopic children, who developed bothersome itching that subsided promptly after cessation of atropine eye drops, were included. History of systemic or ocular allergy, preexisting ocular conditions, and clinical features of allergy were noted. Results: Six children, age 5–15 years, were included. Four developed allergy to 1% atropine sulfate eye drops and two to 0.01% concentration of atropine sulfate. The onset of allergy was within a month to as late as 4 years after using atropine eye drops. The severity of allergy was higher with 1% concentration. The most common symptoms of atropine allergy were itching and burning. The most common signs were lid swelling and hyperemia. The allergic manifestations promptly reversed with the stoppage of eye drops. Reintroduction was possible in three patients, either by reducing the concentration of atropine or using benzalkonium free formulation. Conclusion: Allergy to atropine eye drops in children may develop within a few weeks or after many years of usage. Prompt cessation followed by a reintroduction and continuation of therapy may be possible in few patients.
RESUMO
Reactive arthritis is associated with demonstrable infection at a distant site without evidence of sepsis at the affected joint(s). We present a rare case reactive arthritis where no bacterial or chlamydial infections could be established, rather larvae of Strongyloides stercoralis could be demonstrated in the stool and duodenal biopsy. Reactive arthritis, psoriasiform lesions and malabsorption with hypoproteinaemia, responded to successful treatment with antihelminthic drugs. Early recognition and adequate treatment for gastrointestinal infections and infestations before complications is important.