tetracycline and hydroxyethyl-methacrylate

In order to utilize the psyllium husk, a medicinally important natural polysaccharide, to develop the hydrogels meant for the drug delivery, we have prepared psyllium 2-hydroxylethylmethacrylate (HEMA) and acrylamide (AAm)-based polymeric networks by using N,N'-methylenebisacrylamide (N,N'-MBAAm) as crosslinker and ammonium persulfate (APS) as initiator. The polymeric networks thus formed [psy-cl-poly(HEMA-co-AAm)] were characterized with FTIR and swelling studies which were carried out as a function of crosslinker concentration, time, pH and [NaCl] of the swelling medium. The swelling kinetics of the hydrogels and in vitro release dynamics of model drug (tetracycline hydrochloride) from these hydrogels has been studied for the evaluation of swelling mechanism and drug release mechanism from the hydrogels. The values of the diffusion exponent 'n' have been obtained 0.5 for both swelling kinetics and drug release dynamics. This value shows that the Fickian type diffusion mechanism has occurred for the swelling of the polymers and for the release of drug from the polymers in different release mediums. The values of the initial diffusion coefficients (10.6 x 10(-4), 13.1 x 10(-4), 14.0 x 10(-4))cm(2)/min, average diffusion coefficients (22.2 x 10(-4), 25.7 x 10(-4), 27.0 x 10(-4))cm(2)/min and late diffusion coefficients (1.68 x 10(-4), 2.15 x 10(-4), 2.28 x 10(-4))cm(2)/min for the release of tetracycline HCl respectively in distilled water, pH 2.2 buffer and pH 7.4 buffer from the drug loaded samples shows that in the initial stages, the rate of release of drug from the hydrogels is slow and rate of diffusion of drug increases with time.

Topics: Acrylamides; Ammonium Sulfate; Animals; Anti-Bacterial Agents; Chemistry, Pharmaceutical; Colon; Cross-Linking Reagents; Diffusion; Drug Carriers; Drug Compounding; Humans; Hydrogels; Hydrogen-Ion Concentration; Kinetics; Methacrylates; Models, Chemical; Psyllium; Sodium Chloride; Solubility; Spectroscopy, Fourier Transform Infrared; Technology, Pharmaceutical; Tetracycline; Water

This study was performed to evaluate the enzyme production in response to implantation of the hydrogel material used in the experimental Chirila keratoprosthesis (KPro) and to assess the effects of five topical drugs on enzyme production and activity. KPros may be extruded from the cornea as a result of tissue melting, a process that involves excessive enzyme activity. To reduce the possibility of implant loss for the hydrogel Chirila KPro, a number of antiinflammatory drugs that have been used to treat other corneal melting conditions were investigated for their effect on initial collagenase activity after the implantation of KPro material into the rabbit cornea.. Poly(2-hydroxyethyl methacrylate) sponge pieces were implanted into rabbit corneas. Prednisolone, tetracycline, medroxyprogesterone, acetylcysteine, and sodium citrate were assessed for effects on gelatinolytic activity and stromal collagenase [matrix metalloprotease-1 (MMP-1)] production in vivo and in vitro by using zymography and Western blotting techniques.. Whereas all five anticollagenase drugs were effective in reducing gelatinolytic activity in vitro, many were ineffective in vivo. However, medroxyprogesterone caused a reduction of gelatinolytic activity in vivo. The amount of MMP-1, as measured by immunoblotting, also was reduced by medroxyprogesterone treatment when compared with untreated controls. An increase in the apparent molecular weight of MMP-1 in operated corneas appears to be the result of the association of MMP-1 with collagen fragments resulting from the surgical trauma.. This study indicates that topical medroxyprogesterone may be a useful adjunctive therapy after prosthokeratoplasty.

Topics: Acetylcysteine; Administration, Topical; Animals; Blotting, Western; Citrates; Collagenases; Cornea; Disease Models, Animal; Electrophoresis, Polyacrylamide Gel; Gelatinases; Graft Survival; Implants, Experimental; Matrix Metalloproteinase Inhibitors; Medroxyprogesterone; Methacrylates; Ophthalmic Solutions; Prednisolone; Rabbits; Sodium Citrate; Tetracycline; Treatment Outcome