Acrylic acid-methyl methacrylate (2.5:7.5/2:8) enteric copolymer for colon targeted drug delivery.
Enteric copolymers of acrylic acid and methyl methacrylate (2.5:7.5 and 2:8) were prepared using tetrahydrofuran as solvent and AIBN as free radical initiator for colon targeting. FTIR and (1)H NMR spectra of the copolymers showed absence of vinyl bond/protons present in the monomers suggesting successful polymerization. Flurbiprofen sodium microspheres (M1 and M2) made with the copolymers, by oil/oil solvent evaporation, were spherical, anionic (zeta potential -57.8 and -53.7 mV) and contained 5.47 and 5.89% drug. FTIR spectrum of microspheres showed peaks for aromatic C = C stretching and substituted benzene ring, indicating entrapment of flurbiprofen. PXRD revealed crystalline structure of flurbiprofen while copolymer and microspheres were amorphous. DSC thermograms showed a sharp melting endotherm of flurbiprofen sodium at 129.26°C against broad endotherms of copolymers and microspheres. The microspheres released 43 and 36% drug at pH 6.8 in 2 h and 99 and 96% at pH 7.4 in next 3-4 h.The microspheres did not adhere on gastric-mucosa at pH 1.2 but showed mucoadhesion time of 18 min and 9 min on intestinal mucosa at pH 6.8. Thus, the microspheres on oral administration, would release the drug in colon, suggesting the potential of the hemocompatible copolymers for pH dependent colon targeted drug delivery system.
Department of Pharmaceutical Chemistry, Dolphin (PG) Institute of Biomedical and Natural Sciences, Manduwala, Dehradun, Uttarakhand, India.
Saurabh
S
Vijay
O P
OP
Sati
Dipak K
DK
Majumdar
D000179:Acrylates / Q000737:chemistry*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000493:pharmacokinetics; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D004339:Drug Compounding / Q000379:methods; D016503:Drug Delivery Systems / Q000379:methods*; D005480:Flurbiprofen / Q000008:administration & dosage / Q000493:pharmacokinetics; D005753:Gastric Mucosa / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism; D020366:Methylmethacrylate / Q000737:chemistry*; D008863:Microspheres; D009994:Osmolar Concentration; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry; D012756:Sheep; D013270:Stomach / Q000187:drug effects; D013608:Tablets, Enteric-Coated / Q000008:administration & dosage / Q000138:chemical synthesis* / Q000737:chemistry; D014867:Water / Q000378:metabolism; D017155:Wettability
D000179:Acrylates; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004337:Drug Carriers; D011108:Polymers; D013608:Tablets, Enteric-Coated; D014867:Water; D020366:Methylmethacrylate; D005480:Flurbiprofen; C036658:acrylic acid