The Pharmacological Basis of Therapeutics A Textbook of Pharmacology, Toxicology and Therapeutics for Physicians and Medical Students. By Prof. Louis Goodman and Prof. Alfred Gilman. Pp. xiii + 1383. (New York: The Macmillan Company, 1941.) 50s. net.

The Pharmacological Basis of Therapeutics

Quercetin is a bioactive compound that is widely used in botanical medicine and traditional Chinese medicine due to its potent antioxidant activity. In recent years, antioxidant activities of quercetin have been studied extensively, including its effects on glutathione (GSH), enzymatic activity, signal transduction pathways, and reactive oxygen species (ROS) caused by environmental and toxicological factors. Chemical studies on quercetin have mainly focused on the antioxidant activity of its metal ion complexes and complex ions. In this review, we highlight the recent advances in the antioxidant activities, chemical research, and medicinal application of quercetin.

Antioxidant Activities of Quercetin and Its Complexes for Medicinal Application.

Background Rutin is a common dietary flavonoid which has received great attention in literature, due to their pharmacological properties, including antimicrobial, anti-inflammatory, anticancer, antidiabetic, inter alia . Over 860 products containing rutin are currently marketed in the US. The major disadvantage associated with rutin is its constrained bioavailability, mainly caused by its low aqueous solubility, poor stability and limited membrane permeability. Scope and approach The aim of this contribution is to give an overview of the current methods (conventional and innovative) for the extraction, identification and purification of rutin. Furthermore, recent findings regarding its pharmacological activities and the different approaches to increase rutin solubility in both aqueous and lipid phases will be discussed. Key findings and conclusions Current trends on extraction process have been focused on the discovery and design of green and sustainable extraction techniques to optimize the recovery of rutin. Despite the bioactivity expressed in different in vitro systems, its biological effects in vivo are limited by the poor bioavailability of the flavonoid. The utilization of delivery systems for rutin or its enzymatic or chemical transformation towards highly soluble derivatives have the potential to improve rutin bioavailability, as well as its stability and/or specific biological properties. These novel rutin formulations may bring this promising flavonoid to the forefront of nutraceuticals for the prevention and/or treatment of various chronic human diseases.

Rutin: A review on extraction, identification and purification methods, biological activities and approaches to enhance its bioavailability

Introduction: Natural compounds such as bioflavonoids have found application in health care system due to their wide biological activities, high safety margins and lower cost. Rutin, a polyphenolic bioflavonoid has shown wide range of pharmacological applications due to its significant antioxidant properties. Conventionally, it is used as antimicrobial, antifungal, and antiallergic agent. However, current research has shown its multispectrum pharmacological benefits for the treatment of various chronic diseases such as cancer, diabetes, hypertension and hypercholesterolemia. Its use is advantageous over other flavonoids as it is a nontoxic and nonoxidizable molecule. Areas covered: This review focus on various studies done on rutin explaining its broad spectrum pharmacological activities. In addition, this review will also focus on the challenges associated with the drug and various approaches to improve the oral bioavailability of rutin. Expert opinion: Rutin is a highly potent molecule due to its strong...

Rutin : therapeutic potential and recent advances in drug delivery.

Platelet-rich plasma (PRP) has emerged as a new treatment modality in regenerative plastic surgery, and preliminary evidence suggests that it might have a beneficial role in hair regrowth. Here, we report the results of a randomized, evaluator-blinded, placebo-controlled, half-head group study to compare, with the aid of computerized trichograms, hair regrowth with PRP versus placebo. The safety and clinical efficacy of autologous PRP injections for pattern hair loss were investigated. PRP, prepared from a small volume of blood, was injected on half of the selected patients’ scalps with pattern hair loss. The other half was treated with placebo. Three treatments were administered to each patient at 30-day intervals. The endpoints were hair regrowth, hair dystrophy as measured by dermoscopy, burning or itching sensation, and cell proliferation as measured by Ki67 evaluation. Patients were followed for 2 years. Of the 23 patients enrolled, 3 were excluded. At the end of the 3 treatment cycles, the patients presented clinical improvement in the mean number of hairs, with a mean increase of 33.6 hairs in the target area, and a mean increase in total hair density of 45.9 hairs per cm2 compared with baseline values. No side effects were noted during treatment. Microscopic evaluation showed the increase of epidermis thickness and of the number of hair follicles 2 weeks after the last PRP treatment compared with baseline value (p < .05). We also observed an increase of Ki67+ keratinocytes in the epidermis and of hair follicular bulge cells, and a slight increase of small blood vessels around hair follicles in the treated skin compared with baseline (p < .05). Relapse of androgenic alopecia was not evaluated in all patients until 12 months after the last treatment. After 12 months, 4 patients reported progressive hair loss; this was more evident 16 months after the last treatment. Those four patients were re-treated. Our data clearly highlight the positive effects of PRP injections on male pattern hair loss and absence of major side effects. PRP may serve as a safe and effective treatment option against hair loss; more extensive controlled studies are needed.

https://stemcellsjournals.onlinelibrary.wiley.com/doi/pdf/10.5966/sctm.2015-0107

The Effect of Platelet-Rich Plasma in Hair Regrowth: A Randomized Placebo-Controlled Trial

Effect of Hydrophilic Excipients on Cyclodextrin Complexes of Acyclovir in Improving Solubility, Dissolution and Permeability

In the present study, guar gum based matrix tablets of dexamethasone were prepared as colon-targeted drug delivery systems for the prevention of Inflammatory Bowel Disease (IBD). Matrix tablets with different proportions of gum:drug were prepared by direct compression technique. Prepared matrix tablets were evaluated for their hardness, weight variation, friability test, drug content, thickness and diameter test. Prepared matrix tablets were also subjected to the measurement of mass degree of swelling and gel strength and were found to be in the range of 2.56-3.16ml and 5.30-10.05ml for the matrix and immediate release tablets, respectively. The swelling of the guar gum-based formulation was found to be linear with increasing percentage of guar gum. Invitro release studies of formulations were performed for 24 hours and compared against the control and with the immediate release formulation. All the matrix tablets showed zero order release kinetics. It was concluded that formulation F2-50 (with 50% guar gum) prolonged the release of drug effectively and thus can be used to target dexamethasone to colon.

Formulation and evaluation of dexamethasone matrix tablets for colon specific delivery

Iontophoretic drug delivery system

Doxycycline hyclate is Biopharmaceutical Classification System, class I drug (high solubility and high permeability), but it is associated with poor photostability. It is in the class of tetracycline antibiotic, which is used to treat various infections, but its bioavailability is compromised due to its sensitivity to light and aqueous instability. In this paper, the influence of inclusion complexation with different cyclodextrins, i.e., αCD, γCD, HPβCD and RMβCD, on the photostability of doxycycline hyclate in aqueous media was investigated. Host–guest inclusion complexes were prepared by freeze- drying method. The prepared complexes were characterized for drug content, SEM, XRPD, in vitro permeation studies and photostability studies. XRPD showed diffused peaks for most of the complexes, while SEM showed irregularly shaped particles. The formulation D20 (Drug: γCD in 1:20 molar ratio) showed the highest % drug content (83.72 ± 1.2%), and the formulations D1 (Drug: αCD in 1: 2 molar ratio) showed the lowest % drug content among all the CD complexes. It was found that the photodegradation of the drug was reduced significantly upon complexation. For Drug: CD complexes, the photostability of the aqueous solution of drug/CD complexes was found to be in the order of γCD > RMβCD > HPβCD > αCD with maximum photostability shown by Drug: γCD (1:20 molar ratio) complex. The obtained results suggested that cyclodextrin complexation can be used as an alternative approach for increasing the photostability of doxycycline hyclate.

Mona Semalty

Papers

Effect of Hydrophilic Excipients on Cyclodextrin Complexes of Acyclovir in Improving Solubility, Dissolution and Permeability

Formulation and evaluation of dexamethasone matrix tablets for colon specific delivery

Iontophoretic drug delivery system

Preparation and characterization of cyclodextrin complexes of doxycycline hyclate for improved photostability in aqueous solution

Obesity and Herbal Drug Research: Exploring the Safer Alternative and Lead Molecule