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PROJECT TOPIC:  THE STABILITY OF IBUPROFEN SUSPENSION FORMULATED WITH TERMINALIA MANTALY (TMM) GUM (A NATURAL SUSPENDING AGENT) AND THE RELEASE PROFILE OF THE FORMULATED SUSPENSION.
Department:  Bio Chemistry
AMOUNT:  30,000
FORMAT:   MS WORD
PAGES:  180
 
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CHAPTER ONE

1.0 INTRODUCTION

 

1.1       Background

 Pharmaceutical suspensions are an important dosage form and are still widelyin use by a large proportion of the population. It is the preferred mode of drug administration when the patient cannot swallow tablets or capsules. A pharmaceutical suspension is  a liquid system but the solid material(usually the drug) does not dissolve in the vehicle to an appreciable extent but remains as solid particles which are evenly distributed throughout the vehicle(Aulton,2013).Thus the active pharmaceutical ingredient (API) consist of indiffusible solid particles. Suspensions are heterogeneous systems consisting of two phases. The external phase,also known as the continuous phase, is generally a liquid vehicle which may be aqueous or non aqueous (hydrophilic or hydrophobic) or semisolid (e.g., gels), and the internal or dispersed phase which is made up of particulate matter such as the active pharmaceutical ingredient (API), which is practically insoluble in the external phase. Most pharmaceutical suspensions consist of an aqueous dispersion medium and generally water is the vehicle of choice in formulating suspensions due to its non toxicity. A suspension can be defined as a dispersion containing a solid material (the dispersed phase) dispersed in a liquid (the continuous phase) without reference to the particle size of the solidmaterial (Aulton,2013). A pharmaceutical suspension is a coarse dipersion which involves dispersion of insoluble particles in a liquid medium(Martin,2011). Typically, the suspensions with particle size greater than 1 µm are known as coarse suspension, while those below 1µm are grouped as colloidal suspension (Kulshreshtha et al,2010). When the particles constituting the internal phase of the suspension are therapeutically active, the suspension is known as a pharmaceutical suspension. Depending on their intended route of delivery, pharmaceutical suspensions can be broadly classified as parenteral suspension, topical suspensions, and oral suspensions (Martin et al. 1983). The physical characteristics of a suspension depend on their intended route of delivery. Oral suspensions generally have high viscosity and may contain high amounts of dispersed solid. A parenteral suspension on the other hand usually has low viscosity and contains less than 5% solids.  Suspensions are not optically clear like solutions and appear cloudy unless the size of the particles falls within the colloidal range and they are an important class of pharmaceutical dosage forms. The advantages of suspension dosage forms include effective dispensing of hydrophobic drugs; masking  of  unpleasant  taste  of  certain ingredients; offering resistance to degradation of drugs due to hydrolysis, oxidation, or microbial activity; easy swallowing for  young  or  elderly  patients; achieve controlled/sustained drug release and  efficient  intramuscular depot  therapy(Fahr and Liu,2007).  In addition,when compared to solution dosage forms, relatively higher concentration of drugs can be incorporated into suspension products(Yarnykh et al,2017).The dispersed phase in a suspension must have to remain suspended in the system for an appreciable time to allow the withdrawal or dispensing of uniform dosage for administration, thus, making it necessary to include in the dosage form, a suspending agent which reduces the rate of settling and permits easy re-dispersion of any settled particulate matter by increasing the consistency of the suspending medium (Bamiro et al,2013). Ideally, the continuous phase (usually water) cannot support the suspension of the disperse phase thereby leading to resettlement on standing. It is imperative that formulators incorporate suspending agents to reduce the rate of settling and also permit easy re-dispersion of the insoluble matter or in diffusible solids.

Suspending agents are usually polymeric materials which are able to enhance the viscosity of the continuous phase thereby retarding the settling of suspended particles.

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