Research Progress of Transdermal Patches in Veterinary Drug Preparations

With the development of pharmaceutics and other disciplines theories and advanced technologies, the application of many new drug delivery systems has gradually increased in clinical veterinary. Among the many drug delivery systems, transdermal patch can maintain stable and effective plasma concentration and therapeutic effect in vivo for a long time after skin dressing delivery, which provides a safe and effective drug-delivery way for the therapy and prevention of some chronic diseases and partial analgesia in a simple and convenient way. Veterinary drug transdermal preparations have been developed both at home and abroad, and satisfactory results have been achieved in the experimental application. Based on the study of veterinary transdermal patches at home and abroad, this paper systematically describes the development and characteristics of transdermal patches, the factors affecting skin permeation and the evaluation this type of preparations in veterinary drugs.

A continued study on the bisoprolol and isosorbide dinitrate transdermal patches:cardiovascular protection in spontaneously hypertensive rats

The objective of the present study is to examine cardiovascular protective action of a newly developed transdermal patch by incorporating bisoprolol and isosorbide dinitrate in spontaneously hypertensive rats. As the combination therapy with these two synergistic drugs at low doses through a suitable form of administration could provide optimal therapeutic benefit, we further evaluated the effects of a 42 d period of anti-hypertensive treatment in spontaneously hypertensive rats. Rats were divided into the following five groups： control （blank patch）, bisoprolol fumarate tablets （BP-FT, 20.0 mg/kg, i.g.）, bisoprolol transdermal patch （BP-TP, 20.0 mg/kg）, isosorbide dinitrate transdermal patch （ISDN-TP, 20.0 mg/kg）, and the combination of BP and ISDN in a transdermal patch at low doses （8 and 12 mg/kg, respectively）. The effects of treatment were evaluated via biochemical indicators related to cardiovascular protection, structure and function. The combination therapy had synergistic anti-hypertensive effects and significantly reduced blood pressure with the benefit of controlling blood pressure variability compared to BP-FT and BP-TP. The combined treatment also reduced heart rate as well as BP-FT and BP-TP, while ISDN-TP had no evident effects on blood pressure, heart rate, and cardiovascular protection. Combination therapy was superior to BP-TP and BP-FT at increasing blood atrial natriuretic peptide and nitric oxide, while also reducing cardiac hydroxyproline and endothelin-1 with no difference in blood endothelin-1 and cardiac malondialdehyde levels. Cardiovascular remodeling differed among the groups, with the combination therapy reducing cardiac hypertrophy and the aortic media/lumen ratio. The consequential improvements in relaxation in response to cumulative concentrations of acetylcholine may explain the associated improvement in endothelial function. Combi- nation treatment with a transdermal patch exhibited a synergistic therapeutic effect. Such favorable cardiovascular effects with nitric oxide donors and β-blockade combination through a transdermal patch may provide long-term cardiovascular protection during anti-hypertensive treatment.

Expert consensus of the Chinese Association for the Study of Pain on pain treatment with the transdermal patch

Chronic pain lasting more than 3 mo,or even several years can lead to disability.Treating chronic pain safely and effectively is a critical challenge faced by clinicians.Because administration of analgesics through oral,intravenous or intramuscular routes is not satisfactory,research toward percutaneous delivery has gained interest.The transdermal patch is one such percutaneous delivery system that can deliver drugs through the skin and capillaries at a certain rate to achieve a systemic or local therapeutic effect in the affected area.It has many advantages including ease of administration and hepatic first pass metabolism avoidance as well as controlling drug delivery,which reduces the dose frequency and side effects.If not required,then the patch can be removed from the skin immediately.The scopolamine patch was the first transdermal patch to be approved for the treatment of motion sickness by the Food and Drug Administration in 1979.From then on,the transdermal patch has been widely used to treat many diseases.To date,no guidelines or consensus are available on the use of analgesic drugs through transdermal delivery.The pain branch of the Chinese Medical Association,after meeting and discussing with experts and based on clinical evidence,developed a consensus for promoting and regulating standard use of transdermal patches containing analgesic drugs.

Multicenter Clinical Study for Evaluation of Efficacy and Safety of Transdermal Fentanyl Matrix Patch in Treatment of Moderate to Severe Cancer Pain in 474 Chinese Cancer Patients

Objective: Although a new matrix formulation fentanyl has been used throughout the world for cancer pain management, few data about its efficacy and clinical outcomes associated with its use in Chinese patients have been obtained. This study aimed to assess the efficacy and safety of the new system in Chinese patients with moderate to severe cancer pain. Methods: A total of 474 patients with moderate to severe cancer pain were enrolled in this study and were treated with the new transdermal fentanyl matrix patch (TDF) up to 2 weeks. All the patients were asked to record pain intensity, side effects, quality of life (QOL), adherence and global satisfaction. The initial dose of fentanyl was 25 ?g/h titrated with opioid or according to National Comprehensive Cancer Network (NCCN) guidelines. Transdermal fentanyl was changed every three days. Results: After 2 weeks. The mean pain intensity of the 459 evaluated patients decreased significantly from 5.63?1.26 to 2.03?1.46 (P<0.0001). The total remission rate was 91.29%, of which moderate remission rate 53.16%, obvious remission rate 25.49% and complete remission rate 12.64%. The rate of adverse events was 33.75%, 18.78% of which were moderate and 3.80% were severe. The most frequent adverse events were constipation and nausea. No fatal events were observed. The quality of life was remarkably improved after the treatment (P<0.0001). Conclusion: The new TDF is effective and safe in treating patients with moderate to severe cancer pain, and can significantly improve the quality of life.

Mechanistic insights of the controlled release capacity of polar functional group in transdermal drug delivery system:the relationship of hydrogen bonding strength and controlled release capacity

Background:Hydrogen bonding interaction was considered to play a critical role in controlling drug release from transdermal patch.However,the quantitative evaluation of hydrogen bonding strength between drug and polar functional group was rarely reported,and the relationship between hydrogen bonding strength and controlled release capacity of pressure sensitive adhesive(PSA)was not well understood.The present study shed light on this relationship.Methods:Acrylate PSAs with amide group were synthesized by a free radical-initiated solution polymerization.Six drugs,i.e.,etodolac,ketoprofen,gemfibrozil,zolmitriptan,propranolol and lidocaine,were selected as model drugs.In vitro drug release and skin permeation experiments and in vivo pharmacokinetic experiment were performed.Partial correlation analysis,fourier-transform infrared spectroscopy and molecular simulation were conducted to provide molecular details of drug-PSA interactions.Mechanical test,rheology study,and modulated differential scanning calorimetry study were performed to scrutinize the free volume and molecular mobility of PSAs.Results:Release rate of all six drugs from amide PSAs decreased with the increase of amide group concentrations;however,only zolmitriptan and propranolol showed decreased skin permeation rate.It was found that drug release was controlled by amide group through hydrogen bonding,and controlled release extent was positively correlated with hydrogen bonding strength.Conclusion:From these results,we concluded that drugs with strong hydrogen bond forming ability and high skin permeation were suitable to use amide PSAs to regulate their release rate from patch.

Multi-compartmental transdermal patch for simultaneous delivery of multiple drugs:formulation and evaluation of newly developed novel dosage form

Objective:To evaluate the formulation of multi-compartmental transdermal patches for simultaneous delivery of multiple drugs:aceclofenac and serratiopeptidase.Methods:The patch was prepared by simple solvent casting method using hydroxy propyl methyl celluloseK100Mas matrix forming agent and dimethyl sulphoxide as permeation enhancer.The prepared transdermal patch was evaluated by physiochemical parameters andin-vitro diffusion studies.Results:The multi-compartmental transdermal patch showed sustained drug release over the period of 12 h.Conclusions:Multicompartmental transdermal patches shows better bioavailability,therapeutic efficacy and very economic as compared with other dosage forms.