Topical alprostadil cream for the treatment of erectile dysfunction

Erectile dysfunction (ED) has serious negative consequences on both sexual experience and emotional well being and affects a broad range of age groups. The prevalence of ED is associated with increasing age and has been reported to be as high as 70%. Although the disorder is common and underdiagnosed, its treatment can significantly improve patients’ quality of life. Systemic treatment with oral phosphodiesterase type-5 (PDE-5) inhibitors is the current standard of care for patients with ED. Some patients, however, have absolute contraindications for PDE-5 inhibitors. In addition, these agents can be associated with adverse effects. Furthermore, because PDE-5 inhibitors are not as effective in patients who have undergone radical prostatectomy or who have severe vascular disease, a substantial unmet medical need exists among patients who have ED as a result of these conditions. Consequently, PDE-5 inhibitor therapy is associated with a high rate of discontinuation, as are intracavernosal or transurethral therapies, which are inconvenient and invasive. Several studies, including four double-blind, placebo-controlled, Phase II trials, show that alprostadil topical cream is efficacious and well-tolerated in ED in patients with mild-to-severe symptoms, in those undergoing treatment for cardiovascular diseases and diabetes and in otherwise healthy ED patients. Thus, alprostadil topical cream is a potential first-choice alternative for ED in patients who do not respond or who cannot tolerate or do not accept PDE-5 inhibitor therapy.     

Optimization of self-nanoemulsifying systems for the enhancement of in vivo hypoglycemic efficacy of glimepiride transdermal patches

Objectives: To optimize and use of glimepiride (GMD)-loaded self-nanoemulsifying delivery systems (SNEDs) for the preparation of transdermal patches.

Methods: Mixture design was utilized to optimize GMD-loaded SNEDs in acidic and aqueous pH media. Optimized GMD-loaded SNEDs were used in the preparation of chitosan (acidic) and hydroxypropyl methyl cellulose (HPMC) (aqueous) films. The prepared optimized formulations were investigated for ex vivo skin permeation, for in vivo hypoglycemic activity and for their pharmacokinetic parameters using animal model.

Results: The optimized formulations showed flux value of (2.88 and 4.428 μg/cm²/h) through rat skin for chitosan and HPMC films, respectively. The pattern of GMD release from both formulations was in favor of Higuchi and approaching zero order models. The n values for Korsmeyer–Peppas equation were characteristic of anomalous (non-Fickian) release mechanism. Moreover, HPMC patches have shown significant reductions (p < 0.05) in blood glucose levels; (213.33 ± 15.19) mg/100 ml from the base-line measurement after 12 h of application.

Conclusions: Optimized GMD SNEDs patches were found to improve GMD skin permeability and the essential pharmacokinetic parameters. Further extensive pre/clinical studies are necessary prior to use transdermal GMD as a valuable alternative to peroral dosage forms with improved bioavailability, longer duration of action and more patient convenience.     

Preparation and evaluation of dl-praeruptorin A microemulsion based hydrogel for dermal delivery

Abstract

The purpose of the present investigation was to develop and optimize the microemulsion (ME) as a transdermal system for Pd-Ia, a poor water soluble and low bioavailable drug. The pseudo-ternary phase diagrams were constructed for various ME formulations including oleic acid as the oil phase, Cremophor RH40 as the surfactant, ethanol as the cosurfactant, and water. The maximum cumulative amount permeated through rat abdominal skins per unit area in 32?h (Q₃₂), and the maximum flux were evaluated using the Franz diffusion cell in order to optimize the ME formulation. The results indicated that the optimized ME formulation was composed of oleic acid (5%, W/W), Cremophor RH40 (13.33%, W/W), ethanol (26.67%, W/W), and water (55%, W/W); the maximum cumulative amount of Pd-Ia was 354.330?±?12.006?μg?cm^?2, the maximum flux was 11.467?±?0.500?μg?cm^?2?h^?1. ME-gel was administered transdermally to rats. The mean plasma concentration of Pd-Ia following transdermal application of ME-gel could be maintained for 32?h at least and the half-life was evidently prolonged. It shows that the ME-gel could be a promising vehicle for dermal delivery of Pd-Ia.     

Controlled release systems for insulin delivery

Diabetes mellitus is a major cause of mortality in industrialised countries, and insulin has remained indispensable in the treatment of diabetes mellitus since its discovery. Generally, patients with diabetes mellitus need a relatively constant basal insulin supply to mimic a near-normal physiological pattern of insulin secretion. However, as a consequence of very short in vivo half-lifes, poor oral bioavailability and current lack of alternative delivery routes, insulin requires single or multiple daily subcutaneous injections to achieve the desired therapeutic effect, which is inconvenient and painful and with poor patient compliance. Therefore, there is a need for insulin delivery systems that have the capability of releasing the loaded insulin at a controlled and sustained rate for a prolonged period. This review examines recent (2000 – 2004) patents on the controlled release systems for insulin delivery, including those for injectable, oral, pulmonary and transdermal delivery, and the glucose-responsive controlled-release systems.     

A systematic review of medication administration errors with transdermal patches

Introduction: Transdermal patches provide an attractive route of drug delivery with considerable advantages over other routes of administration, for example maintenance of constant plasma drug levels and convenient usage. However, medication administration errors abound with this dosage form and frequently result in harm or treatment failure.

Areas covered: A systematic literature search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using appropriate keywords to identify articles reporting faulty transdermal patch administration. Common pitfalls and errors that were identified through the systematic literature search were discussed alongside individual steps of the transdermal patch administration process.

Expert opinion: The systematic investigation of published errors illustrated that every step in the transdermal patch administration process is prone to errors. Thereby, the lack of knowledge and awareness of the importance of a correct administration practice were a major source of risk. Based on the identified errors and causes of errors prevention strategies were developed as a first step in avoiding transdermal patch administration errors.     

高乌甲素脂质体凝胶制备工艺及体外释药性能研究

目的：制备高乌甲素脂质体（LA-LIP）经皮给药制剂，对其质量及透皮吸收性质进行考察。方法：采用薄膜分散法制备LA-LIP，以包封率与载药量为指标，运用正交试验法确定LA-LIP的优选处方；以卡波姆-940为基质制备LA-LIP凝胶，采用体外释放试验评估释放能力。结果：正交试验法确定LA-LIP最佳处方工艺组合为卵磷脂与胆固醇质量比为8：1、药脂比为1：8、水化温度为55℃。体外透析袋实验显示，LA-LIP凝胶慢释过程符合Higuchi方程，LA凝胶释放过程符合零级动力学方程；体外透皮结果显示，LA凝胶24 h内皮肤滞留量为8.39 μg·cm^-2，LA-LIP凝胶皮肤滞留量为15.17 μg·cm^-2。结论：本研究发现运用薄膜分散法制备LA-LIP工艺简单可靠，制备成脂质体凝胶剂时，具有缓释效果。     

日夜两用生长激素微针贴片的制备及体外评价

目的 制备日夜两用生长激素微针贴片，模拟人体生理状态下内源性生长激素分泌的昼夜差异，实现生长激素给药时间和用量的优化，同时有效减轻皮下注射给药疼痛感，提高患者使用依从性。方法 采用铸模法制备微针贴片，通过光学显微镜和扫描电子显微镜观察微针表面形貌。经体外释放试验确定含生长激素微针制备的最佳工艺条件，包括优化紫外交联时间和交联剂含量。通过微针力学强度测试和体外透皮试验验证微针贴片有效穿透皮肤的可行性，通过圆二色光谱测定药物的稳定性。通过调试负载不同剂量生长激素制备日用和夜用微针贴片。结果 在显微镜下观察到微针排列整齐，针体完整、尖锐，微针在药物释放前后形貌无明显差异。工艺优化结果表明，当紫外交联时间为7 min，交联剂用量为1.5%时，微针贴片可以有效穿透离体大鼠皮肤，同时实现了生长激素在12 h内稳定释放，且微针释放出的蛋白药物构象无明显变化。通过在针体中负载不同剂量生长激素，制备了日用和夜用生长激素微针贴片。结论 本研究制备的微针能够顺应在生理状态下生长激素分泌的日夜差异，实现了适宜时间释放适量生长激素的目标，未来可进一步优化微针药物负载量以满足不同患者的实际使用需求，以期实现个体化治疗。     

Transdermal Opioid Patches for Pain Treatment in Ancient Greece

Abstract: Pain treatment in ancient Greece, and through the middle ages in Europe, was to a great extent based on the expertise of the Greek physician Galen (c. 129–200 A.D.). Galen makes particular reference to “Olympic Victor’s Dark Ointment” (OVDO), which is listed with a number of collyria. Galen states that OVDO can be useful for treating extreme pain and swellings, forming one of the best eye salves. Olympic Victor’s Dark Ointment, an opium‐based treatment, forms a “patch” when applied externally as an ointment, because it quickly dries to cover a localized region but still retains its elastic properties. This study has recreated OVDO and applied the ointment to abdominal mouse skin, in vitro. To assess the efficacy of OVDO, the transdermal transfer of morphine was measured when given as OVDO and compared to morphine administered in the form of a solution of Opium + PBS (ringer). Olympic Victor’s Dark Ointment showed a transdermal transfer of morphine over time comparable to 25% of the most efficient modern transdermal opioid patches, while hardly any morphine was able to penetrate the skin when applied mixed in PBS. We conclude that OVDO is very efficient in its composition and may carry some forgotten abilities in terms of drug delivery, which could be transferred to modern medicine. Indeed, this may lead to a better choice of morphine use and controlled management in individual patient cases, taking both pain relief and anti‐inflammatory aspects into account.     

综合主成分分析法和皮肤电阻法对几种促透剂促透效果的比较

目的 建立一种简单有效的快速评价促透剂透皮吸收促进效果的方法，并比较综合主成分分析法和皮肤电阻法的促透剂评价结果。方法 以氨茶碱作为模型药物，氮酮、薄荷醇、冰片、油酸及其联用作为促透剂，SD大鼠背部离体皮肤作为渗透屏障，HPLC测定接收液中的药物浓度，计算累积渗透量、渗透系数、稳态流量、滞后时间和增渗倍数，运用综合主成分分析法对促透效果进行综合评价；测定在促透剂作用下的大鼠皮肤电阻随时间的变化，评价促透剂对皮肤的作用程度。结果 用Franz扩散池方法结合综合主成分分析法，得到对氨茶碱有促透效果的促透剂有油酸加冰片以及薄荷醇，且油酸加冰片的促透效果大于薄荷醇；用皮肤电阻法测得有促透作用的是油酸加冰片、薄荷醇加氮酮、薄荷醇、氮酮、油酸、冰片加氮酮以及薄荷醇加冰片，且作用程度依次递减。采用皮肤电阻法评价的促透效果与采用体外透皮吸收试验评价的结果基本平行(r=0.886 9)。结论 综合主成分分析法和皮肤电阻法都可以客观评价促透剂的效果，且2种方法具有明显的相关性。     

Hyaluronate – parathyroid hormone peptide conjugate for transdermal treatment of osteoporosis

Abstract

Human parathyroid hormone 1–34 fragment (PTH_1–34) has been used as a FDA-approved therapeutics to treat osteoporosis by daily subcutaneous injection. In this work, we successfully developed PTH_1–34 conjugated hyaluronic acid (HA) for the transdermal treatment of osteoporosis with improved patient compliance. HA-PTH_1–34 conjugate was synthesized by the coupling reaction between aldehyde group introduced to HA and amine group of PTH_1–34. After characterization by gel permeation chromatography (GPC) and ELISA, the biological effect of HA-PTH_1–34 conjugate on the proliferation of human osteoblast cells was confirmed by in vitro calcium colorimetric assay and cAMP assay. Two-photon microscopy clearly visualized the effective skin penetration of FITC modified HA-PTH_1–34 conjugate. The transdermally delivered HA-PTH_1–34 conjugates elevated the blood calcium concentration for more than 2 days, reflecting the feasibility for the treatment of osteoporosis.