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ABSTRACT: This work is focused on the development of controlled drug delivery systems using different wax/fat embedded indomethacin (IM). Discrete wax/fat embedded microspherules containing indomethacin were prepared by using cetostearyl alcohol, paraffin wax and stearic acid by employing emulsification-phase separation method. These matrices have been used as barrier coatings due to their hydrophobic nature. Chemically inert and tasteless nature of wax/fats promotes their use as taste masking agents for bitter drugs. Various waxes and fats are available having different physicochemical properties to suit the needs of formulation. Methyl cellulose (MC) 1% w/v, sodium alginate (SA) 0.5% w/v and Tween-80 (TW) 1% w/v were used as emulgents. The resulting microspherules were discrete, large, spherical and also free flowing. It is revealed from the literature that natures of wax/fat emulgents were found to influence the rate of drug release. In the present work the drug content in all the batches of microspherules were found to be uniform. The rate of drug release corresponded best to first order kinetics, followed by Higuchi and zero-order equations. The release of the model drug from these wax/fat microspherules was prolonged over an extended period of time and the drug release mechanism followed anomalous (non-Fickian) diffusion controlled as well as Super Case II transport. Among the three matrix materials used, paraffin wax retarded the drug release more than the other two. Surface characteristics of microspherules have been studied by Scanning Electron Microscope (SEM). A fair degree rank of correlation was found to exist between the size and release retardation in all the three-wax/fat emulgent combinations.
Current Drug Delivery 11/2008; 5(4):248-55.
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ABSTRACT: The present study was aimed for the development and evaluation of hydrotropic starch gels of terbinafine hydrochloride which is an allylamine derivative of antifungal agent was formulated by using corn starch and sodium salicylate as hydrotropic salt. The gels were prepared in presence and absence of propylene glycol. The prepared gels were evaluated for in vitro drug release, rheological behavior and microbial studies. The degree of increase in the drug diffusion was found to be in order corn starch gel with propylene glycol was greater than corn starch gel without propylene glycol. The microbial studies were carried out in soya bean casein digest medium with Candida albicans as test organisms and were found to be 22.86 ± 0.58 and 20.22 ± 0.65 mm for TCSG (IV) and TCS (III), respectively. All the gels exhibited shear thinning. The rheogram indicated that the gel systems are pseudoplastic and exhibited thixotropy. The added propylene glycol has not appreciably altered the apparent viscosity values.
Asian Journal of Pharmaceutics. 01/2008;
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ABSTRACT: A study has been carried out to assess the potential use of pectin in combination with two added hydrocolloids, i.e., hydroxy-propyl-methyl cellulose and hydroxyethyl cellulose in varied concentrations and coated with ethyl cellulose and cellulose acetate phthalate. The results of in vitro drug release showed that the matrix tablets prepared with pectin, hydroxy ethyl cellulose (20 percent) when coated with ethyl cellulose and cellulose acetate phthalate were found to be 63.0 percent, 8.4 percent, and 4.5 percent, respectively, in after eight hours during drug release study period. These results were confirmed with the results of roentgenographic studies in nine healthy human volunteers to find the shape and integrity of the dosage form. The X-ray photographs revealed that the enteric-coated tablet was visible only up to 5.5 hours and at the end of eighth hour, the photograph has not shown any presence of tablet indicating the loss of shape and size by the microflora present in the colon region. So, the results of in vitro and roentgenographic studies revealed that pectin, hydroxy ethyl cellulose (20 percent) base coated with ethyl cellulose and cellulose acetate phthalate was found to be a promising carrier for naproxen to colon.
The Yale journal of biology and medicine 08/2003; 76(4-6):149-54.
