R. F. Helwing

Controlled release of water-soluble macromolecules from bioerodible hydrogels

J. Heller, R. F. Helwing, Robert J. Baker et al. · Biomaterials · 1983 · 92 citations

Hydrogels, Engineering, Micro-encapsulation +2

Preparation of poly(ortho esters) by the reaction of diketene acetals and polyols

J. Heller, D. W. H. Penhale, R. F. Helwing · Journal of Polymer Science Polymer Letters Edition · 1980 · 86 citations

Chemical Engineering, Engineering, Ortho Esters +8

Preparation of polyacetals by the reaction of divinyl ethers and polyols

J. Heller, D. W. H. Penhale, R. F. Helwing · Journal of Polymer Science Polymer Letters Edition · 1980 · 51 citations

Chemical Engineering, Engineering, Polymer Science +8

Release of norethindrone from poly(ortho esters)

J. Heller, D. W. H. Penhale, R. F. Helwing et al. · Polymer Engineering and Science · 1981 · 48 citations

Sodium Chloride, Pharmaceutical Science, Engineering +18

Controlled release of contraceptive steroids from biodegradable poly (ortho esters).

J. Heller, D. W. H. Penhale, Bernd Fritzinger et al. · PubMed · 1983 · 21 citations

Hormonal Contraceptive, Contraceptive Implants, Engineering +11