Transdermal patch
A transdermal patch suitable for the administration of nitroglycerin.
1. A drug-in-adhesive type transdermal patch comprising:
a) a backing layer impermeable to nitroglycerin; and
b) a matrix layer consisting essentially of:
(I) between 40% and 45% by weight, based on the dry mass, of nitroglycerin;
(II) between 50% and 55-% by weight, based on the dry mass, of self-cross-linking acrylic acid/2-ethyl-acrylate/methyl-acrylate copolymer;
(III) between 1.5% and 2.5% by weight, based on the dry mass, of sorbitan monooleate;
(IV) between 1% and 3% by weight, based on the dry mass, of propylene glycol; and
(V) between 0% and 7.5% by weight of other pharmacologically acceptable excipients,
wherein no absorption enhancers are present in the patch.
2. The patch as claimed in claim 1 , wherein said matrix layer presents the following percentage composition:
(I) between 43% and 44% by weight, based on the dry mass, of nitroglycerin;
(II) between 52% and 53% by weight, based on the dry mass, of self cross-linking acid/2-ethyl-acrylate/methyl-acrylate copolymer;
(III) between 1.5% and 2.5% by weight of sorbitan monooleate;
(IV) between 1% and 2-% by weight of propylene glycol; and
(V) between 0% and 2-% by weight of other pharmacologically acceptable excipients.
3. The patch as claimed in claim 1 , wherein the excipients of group V are not present.
4. A process for preparing the patch as claimed in claim 1 , comprising the following steps:
a) preparing a semi-solid adhesive mass containing the nitroglycerin and all the other components of the matrix layer;
b) spreading the mass onto a siliconized support to obtain a uniform and homogeneous film;
c) drying the film;
d) bonding the adhesive film to a backing; and
e) cutting the adhesive film on the backing into a desired shape and dimensions.