Volume 4, Issue 3, Jul-Sep 2012

Volume 4

July-September 2012

Nanosuspensions: Advantages and disadvantages

Ashish Kumar Verma, M C Bindal

Abstract:
Nanosuspensions have emerged as a promising strategy for the efficient delivery of hydrophobic drugs because of their versatile features and unique advantages. The poor water solubility of drugs is major problem for drug formulation. To date, nanoscale systems for drug delivery have gained much interest as a way to improve the solubility problems. The reduction of drug particles into the sub-micron range leads to a significant increase in the dissolution rate and therefore enhances bioavailability. Nanosuspensions are promising candidates that can be used for enhancing the dissolution of poor water soluble drugs. Nanosuspensions contain submicron colloidal dispersion of pharmaceutical active ingredient particles in a liquid phase stabilized by surfactants. Production of drugs as nanosuspensions has been developed for drug delivery systems as an oral formulation and non-oral administration. Currently, efforts are being directed to extending their applications in site-specific drug delivery. This review describes the methods of pharmaceutical nanosuspension production, formulations and pharmaceutical applications in drug delivery as well as the marketed products.

Keywords: Nanosuspensions, Drug Delivery, Bioavailability, Colloid.

A review on: Nanosuspensions - An innovative acceptable approach in novel delivery system

Nagare S K, Ghurghure S M, Khade A B, Jadhav S G, Salunkhe S B

Abstract:
Solubility is an essential factor for drug effectiveness, independent of the route of administration. Poorly soluble drugs are often a challenging task for formulators in the industry. Conventional approaches for enhancement of solubility have limited applicability, especially when the drugs are poorly soluble simultaneously in aqueous and in non-aqueous media. Nanosuspension technology can be used to improve the stability as well as the bioavailability of poorly soluble drugs. Nano suspensions are biphasic systems consisting of pure drug particles dispersed in an aqueous vehicle, stabilized by surfactants. These are simple to prepare and are more advantageous than other approaches. Techniques such as wet milling, high pressure homogenization, emulsification-solvent evaporation and super critical fluid have been used in the preparation of nano suspensions. It has the advantage of delivery by various routes, including oral, parenteral, pulmonary and ocular routes.

Keywords: Nanosuspensions, Poorly Soluble Drug, Pulmonary, Parenteral.

Taste masking techniques: An updated review

Bhabani S Nayak, Dinesh K Sharma, P Ellaiah, Suraj Sahoo

Abstract:
Taste masking becomes a prerequisite for bitter drugs to improve the patient compliance especially in the pediatric and geriatric populations. Some orally administered drugs exhibit bitter taste. Two approaches are commonly utilized to overcome the bitter taste of the drug. The first includes reduction of drug solubility in the saliva and second approach is to alter the ability of the drug to interact with taste receptors. Various methods are available to mask the undesirable taste of the drugs. Conventional taste masking techniques such as the use of sweeteners, amino acids and flavoring agents alone are often inadequate in masking the taste of highly bitter drugs. The recent techniques of taste masking are dispersion coating, granulation, solid dispersions, inclusion complexation, ion exchange resin approach, mass extrusions technique, spray drying, microencapsulation, liposomes, prodrugs, salt formation, adsorption, wet spherical agglomerations, multiple emulsions, gel formation, effervescent technique and continuous multipurpose melt (CMT) technology. The field of taste masking of active pharmaceutical ingredients (API) has been continuously evolving with varied technologies and new excipients.

Keywords: Taste, Taste Buds, Taste Masking Techniques, Bitter Drug.

Formulation and in vitro release study of zidovudine sustained release tablets

Deepika V, Sasikanth K

Abstract:
The purpose of the present investigation was to out to formulate sustained release matrix tablets of zidovudine. The sustained release matrix tablets were prepared by wet granulation method by using hydrophilic polymers like HPMC, SCMC and Na Alginate (F1 to F9). A total of nine formulations were prepared using hydrophilic polymers. The formulation F3 was selected for further modification using different hydrophobic polymers as granulating agents, such as PVP, Eudragit RL 100 and Ethylcellulose to control the drug release. The hydrophilic matrix of HPMC alone could not control the Zidovudine release effectively for 12 hours. The formulations F10 to F15 released more than 95% of AZT at the end of 12 hours. The drug polymer interaction were investigated by FTIR studies. Zidovudine tablets were evaluated for various physical tests like weight variation, hardness, friability and results showed they comply with in the limits. Kinetic treatment to the in vitro release data revealed that the drug release followed first order release and mechanism of drug release is by Non-fickian transport. Of all formulations, F15 is the most successful and cost-effective formulation among the matrix tablets developed in the present study.

Keywords: Zidovudine, Hydrophilic Polymers, Hydrophobic Polymers, Sustained Release.

Evaluation of safety and efficacy of stevia moisturiser gel by clinical trial

Kuntal Das, Raman Dang, Lalitha B R

Abstract:
The objective of the present comparative study was to evaluate the safety and efficacy of Stevia moisturiser gel for the period of single application over 21 days. Sixty subjects were included in this study. They were divided in two groups’ viz. group –I (control, without Stevia extract) and group-II (test, gel containing Stevia extract) and each groups contains thirty subjects. They were advised to apply once daily for a period of 21 days. All the subjects were followed up at weekly intervals for a period of 3 weeks. Response to moisturiser gel was evaluated on a scoring system and visual analogue scale. All the subjects were completed the study and significant results observed with respect to reduction in dark complexion, increased in skin softness, skin glow. Measurement of skin hydration after single application of Stevia gel during 3 weeks daily was significantly higher (P value <0.001, paired t-test) than the control skin. The gel is completely free from any reaction due to sun light. None of the volunteers experienced neither any hypersensitivity reactions nor in changes of skin pH and compliance to the use of formulation was potent. Finally, concluded that the Stevia gel could be suggested as a safe and beneficial moisturizer for human application.

Keywords: Complexion, Moisturiser Gel, Stevia Extract, Skin Softness, Skin Hydration, Skin pH.

Non aqueous microemulsions: Ideal vehicles for lipophilic drugs

Shekhar Verma, J S Dangi

Abstract:
Over the past few decades there has been growing interest to develop novel drug delivery systems. These system uses to minimize drug degradation and loss, to prevent harmful side-effects and to increase drug bioavailability and the fraction of the drug accumulated in the required zone, various novel drug delivery systems are currently under development. Among drug carriers one can name non aqueous microemulsions. Conventional emulsions are heterogeneous system in which one immiscible liquid is dispersed as droplets in another liquid. Such a thermodynamically unstable system is kinetically stabilized by addition of one further components that exhibit emulsify properties. In emulsion water is an internal phase dispersed in oil are termed as water-in-oil, whereas, emulsion in which the oil is dispersed and water forms the continuous phase are known as oilin-water emulsions. Emulsion is one of the most convient and advantageous formulation in which one of the liquid phases is water. However emulsion can be formulated without an aqueous phase to produce anhydrous, non-aqueous or oil in oil microemulsions. Such systems, which can replace conventional emulsions where the presence of water to be avoided. The present work was aimed at formulating stable non aqueous emulsions of castor oil and silicone oil, exploring also the possibility of using such systems as anhydrous vehicles for controlled drug release.

Keywords: Non Aqueous Microemulsions, Internal Phase, Thermodynamically Stable System.

Mucoadhesive, doxycycline-loaded hydroxypropyl guar microspheres for the treatment of periodontitis; preparation and in vitro characterization

Zaheer Abbas, Praveen B, Swamy N G N

Abstract:
The objective of the study was to develop a drug delivery system for localised controlled release of Doxycycline following insertion into and/or around the periodontal pocket which would ensure increased local drug concentration over an extended period of time with a subsequent decrease in the side effects associated with systemic administration. Hydroxypropyl Guar, a biodegradable polymer, was used in the preparation of microspheres by employing water in oil emulsification solvent evaporation technique. The formulations were evaluated for particle size, particle shape and surface morphology by Scanning Electron Microscopy, percentage yield, drug entrapment efficiency, in vitro mucoadhesion test, degree of swelling and in vitro drug diffusion through sheep buccal mucosa. The microspheres obtained were free flowing, spherical and had a mean particle size of 110.2 ± 1.13 µm. Increasing polymer concentration resulted in increased drug entrapment efficiency and increased particle size. Doxycycline Hydrochloride was entrapped into the microspheres with an efficiency of 74.7 ± 2.11 % to 83.9 ± 1.54 %. The prepared microspheres showed good mucoadhesion properties, swellability and sustained the release of the drug over a period of 8 h. The data obtained were analysed by fitment into various kinetic models; it was observed that the drug release was matrix diffusion controlled and the release mechanism was found to be non-Fickian. Stability studies were carried out on select formulations at 5°C ± 3°C, 25°C ± 2°C / 60% RH ± 5% RH and 40°C ± 2°C / 75% RH ± 5% RH for 90 days. The drug content was observed to be within permissible limits and there were no significant deviations in the in vitro mucoadhesion and in vitro drug diffusion characteristics.

Keywords: Periodontitis, Doxycycline Hydrochloride, Mucoadhesive Microspheres, Hydroxypropyl Guar, Water in Oil Emulsification Solvent Evaporation Technique, In vitro Mucoadhesion Studies,

Indian Journal of

Novel Drug Delivery ISSN 0975-5500

Indian Journal of Novel Drug Delivery ISSN 0975-5500