title: Evaluation of Skin Penetration of Diclofenac from a Novel Topical Non Aqueous Solution: A Comparative Bioavailability Study.
abstract: BACKGROUND
  Different topical formulations of diclofenac have varying skin penetration profile. Recent advances in science and technology has led to the development of many new formulations of drugs for topical drug delivery. One such technological development has led to the innovation of Dynapar QPS, a novel, non-aqueous, quick penetrating solution (QPS) of diclofenac diethylamine.
  
  
  OBJECTIVE
  This study was aimed to measure the total exposure from the drug penetrating the skin in healthy human subjects and comparing the relative systemic bioavailability of Dynapar QPS(®) with diclofenac emulgel.
  
  
  METHODS
  A 200 mg of diclofenac from either Dynapar QPS(®) (5 ml) or emulgel (20 g) was applied on back of subject as per the randomisation schedule. Blood samples were collected up to 16 hours post drug application. Plasma concentration of diclofenac was measured by pre-validated HPLC method. Pharmacokinetic (PK) parameters like Cmax, Tmax, t1/2, AUC0-t, AUC0-∞, and Kel, of diclofenac were determined for both the formulations.
  
  
  RESULTS
  Mean Cmax after administration of Dynapar QPS(®) and diclofenac emulgel were 175.93 and 40.04 ng/ml, respectively. Tmax of diclofenac was almost half with QPS compared to emulgel (5.24 hrs versus 9.53 hrs respectively). The mean AUC0-t and AUC0-∞ after administration of Dynapar QPS(®) was higher as compared to diclofenac emulgel (AUC0-t: 1224.19 versus 289.78 ng.h/ml, respectively; AUC0-∞: 1718.21 versus 513.83 ng.h/ml, respectively). None of the subject experienced any adverse event during the study.
  
  
  CONCLUSIONS
  The results indicate an enhanced penetration and subsequent absorption of diclofenac from Dynapar QPS(®) as compared to diclofenac emulgel. Higher penetration is likely to translate into better pain relief in patients.
authors.affiliation: Director, B. V. Patel Pharmaceutical Education and Research Development (PERD) Centre , Sarkhej-Gandhinagar Highway, Ahmedabad-Gujarat, India .
authors.forename: Manish
authors.initials: M
authors.lastname: Nivsarkar
authors.affiliation: Senior G.M., Medical Services Department, Troikaa pharmaceuticals Ltd , Ahmedabad, Gujarat, India .
authors.forename: Sanjaykumar H
authors.initials: SH
authors.lastname: Maroo
authors.affiliation: M. Pharm (Pharmaceutical Chemistry), Research and Development, Chairman and Managing Director, Troikaa pharmaceuticals Ltd , Ahmedabad, Gujarat, India .
authors.forename: Ketan R
authors.initials: KR
authors.lastname: Patel
authors.affiliation: M. Pharm, Executive, Medical Services Department, Troikaa pharmaceuticals Ltd , Ahmedabad, Gujarat, India .
authors.forename: Dixit D
authors.initials: DD
authors.lastname: Patel
keywords: Gel; Pharmacokinetics; Quick penetrating solution (QPS); Topical drug
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