title: Development of nitrendipine transdermal patches: in vitro and ex vivo characterization.
abstract: OBJECTIVE
  The aim of the investigation was to develop and evaluate matrix type transdermal drug delivery systems (TDDS) of nitrendipine (NTDP).
  
  
  METHODS
  The matrix type TDDS of NTDP were prepared by solvent evaporation technique. Ten formulations (composed of Eudragit RL 100 and Hydroxypropyl methyl cellulose in the ratios of 5:0, 4:1, 3:2, 2:3, 1:4 in formulations A1, A2, A3, A4, A5 and Eudragit RS 100 and Hydroxypropyl methyl cellulose in the same ratios in formulation B1, B2, B3, B4, B5 respectively) were prepared. All formulations carried 6 % v/w of carvone as penetration enhancer and 15% v/w of propylene glycol as plasticizer in dichloromethane and methanol as solvent system. The prepared TDDS were evaluated for in vitro release, ex vivo permeation, moisture absorption, moisture content and mechanical properties. The physicochemical interactions between nitrendipine and polymers were investigated by Fourier Transform Infrared (FTIR) Spectroscopy.
  
  
  RESULTS
  The maximum drug release in 24 hrs for A series formulations was 89.29% (A4) and 86.17% for B series (B5), which are significantly (p < 0.01) different to the lowest values (57.58 for A1 and 50.64 for B1). Again formulations A4 (flux 23.51 microg/hr/cm(2)) and B5 (flux 22.98 microg/hr/cm(2)) showed maximum skin permeation in the respective series. The flux obtained with formulation A4 and B5 meets the required flux (19.10 microg/hr/cm(2)). The mechanical properties, tensile strength, elastic modulus (3.42 kg/mm(2) for A4 and 4.25 kg/mm(2) for B5) reveal that the formulations were found to be strong but not brittle. FTIR studies did not show any evidence of interaction between the drug and the polymers.
  
  
  CONCLUSIONS
  Nitrendipine matrix type transdermal therapeutic systems could be prepared with the required flux having suitable mechanical properties.
authors.affiliation: Center for Biopharmaceutics and Pharmacokinetics, University College of Pharmaceutical Sciences, Kakatiya University, Warangal-506 009 (A.P), India.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Gannu
authors.forename: Y Vamshi
authors.initials: YV
authors.lastname: Vishnu
authors.forename: V
authors.initials: V
authors.lastname: Kishan
authors.forename: Y Madhusudan
authors.initials: YM
authors.lastname: Rao
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000279:Administration, Cutaneous; D000465:Algorithms; D000818:Animals; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000379:methods; D005079:Excipients / Q000737:chemistry; D065347:Hypromellose Derivatives; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000737:chemistry; D009568:Nitrendipine / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D010539:Permeability / Q000187:drug effects; D011108:Polymers / Q000737:chemistry; D051381:Rats; D012867:Skin / Q000378:metabolism; D012869:Skin Absorption; D012995:Solubility; D013055:Spectrophotometry, Infrared / Q000379:methods; D013678:Technology, Pharmaceutical / Q000379:methods*; D013718:Tensile Strength / Q000187:drug effects
chemical_list: D000180:Acrylic Resins; D002121:Calcium Channel Blockers; D005079:Excipients; D011108:Polymers; C050528:Eudragit RS; D065347:Hypromellose Derivatives; C058665:Eudragit RL; D008747:Methylcellulose; D009568:Nitrendipine