Preparation andin vitroevaluation of polylactic acid-mitomycin C microcapsules

Abstract

An emulsion method was developed for the incorporation of water-soluble mitomycin C into polylactic acid biodegradable microcapsules. With an average particle size of about 95 microns, microcapsules with a desired loading of from 3.65 to 13.80 per cent were prepared. These microcapsules, which contained both crystalline and finely dispersed drug particles, showed a dose-dependent drug release pattern with microcapsules of higher drug loading having a faster release rate than those of lower drug loading. Effective sterilization of the microcapsules for parenteral use was achieved by 60Co gamma-ray irradiation, which did not affect the microcapsule structure, release rate or drug stability. Mitomycin C showed dose-dependent antiproliferative activity against the growth of the K562 human erythroleukaemia cells. The microencapsulated dosage form of mitomycin C was found to enhance the drug's activity through sustained drug release. In experiments where drug concentrations in the cell medium were reduced according to the drug's biological half-life, the microcapsule systems showed a distinct advantage over the non-capsulated dose for the kinetic inhibition of K562 cell growth.

Biopolymer albumin for diagnosis and in drug delivery

“…Hence, the ideal dosage form in cancer therapy is the one that provides a specific delivery of anticancer agent to the tumor site in a sufficient amount, for a long period of time with no interaction with the normal tissue [Gregoriadis, 1977]. Sustained release targeting of antitumor drug to the specific site has received attention during recent years, and albumin, gelatin, and polylactic acid have been evaluated [Willmott and Harrison, 1988;Yoshioka et al, 1981, Tsai et al, 1986.…”

Development and Evaluation of Stavudine Loaded Injectable Polymeric Particulate Systems

“…5-7). That might be attributed to slow degradation characteristics of the RESOMER ® with time [23]. Scanning electron micrograph of the microspheres taken after seven days showed negligible changes in surface morphology whereas samples after 15 days showed some hairline demarcations leading to wrinkled surface of the microspheres.…”

“…The release exponent n and K value were calculated through the slope of the straight line [23,28]. [7] Where M t represents amount of the released drug at time t, M is the total amount of drug released after an infinite time, K is the diffusional characteristic of drug/polymer system constant and n is an exponent that characterizes the mechanism of drug release.…”

Neem Seed Oil: Encapsulation and Controlled Release - Search for a Greener Alternative for Pest Control

“…In the case of extraction, the emulsion is transferred to a large quantity of water or other quench medium, into which the solvent associated with the oil droplets is diffused out. Several reports are available that discusses on the formation of microspheres, for increase of encapsulation efficiency and release pattern of microspheres formed by this method (Jeyanthi, 1996;Arshady, 1991;Cavalier et al, 1986;Jalil, 1990;Tsai et al, 1986). …”