Controlled Delivery of Pilocarpine. 1. In Vitro Characterization of Gelfoam® Matrices

Sreekant R. Nadkarni, Samuel H. Yalkowsky

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


The potential of Gelfoam absorbable gelatin sponge as a carrier for ophthalmic delivery of pilocarpine was examined. Prolonged in vitro release of pilocarpine was achieved through pharmaceutical modification of the device by embedding a retardant in the pores. The device embedded with cetyl ester wax released pilocarpine in a zero-order pattern (release exponent = 0.93 ± 0.04) for up to 5 hr. This result corresponded well with a linear penetrant uptake by this device. The device impregnated with polyethylene glycol 400 mono-stearate exhibited anomalous drug transport with a release exponent of 0.63 ± 0.02. The absorption of water by this retardant and the formation of a gel layer on the surface slowed the penetration of the release medium into the deeper sections of the matrix, as well as the rapid outward diffusion of drug, resulting in a prolonged release of pilocarpine.

Original languageEnglish (US)
Pages (from-to)109-112
Number of pages4
JournalPharmaceutical Research: An Official Journal of the American Association of Pharmaceutical Scientists
Issue number1
StatePublished - Jan 1993


  • absorbable gelatin
  • ophthalmic drug delivery
  • pilocarpine
  • prolonged release
  • zero-order release

ASJC Scopus subject areas

  • Biotechnology
  • Molecular Medicine
  • Pharmacology
  • Pharmaceutical Science
  • Organic Chemistry
  • Pharmacology (medical)


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