Different effect of content of material towards the characteristics of ointment formulation

Aim
To study the effect of content of material towards the characteristics of ointment formulation
Introduction 

Ointment are semisolid preparation intended for external applization to the skin or mucous membrane.They are use topically for many purposes such as antiseptic,antipruritis,kerotolytics and astringents.Also some drug absorbed into the general circulation via skin and produce systematic effect.

In the formulation of ointment ,the base forms the main part of ointment/product.An ointment base is of prime importance because it does not only serve as vehicle but also function as the carrier of medicinal agents in the product.It affect overall quality of an ointment,the release rate of drg substances as well as it absorption into the body.

The commonly used  ointment bases are classified into three different group which are oleaginous bases,emulsion bases, and water soluble bases.Drug release rate of percutaneous absorption mainly depend on the nature of the drug itself.However the composition and properties of ointment bases also influences the drug release and percutaneous absorption to the certain extent.Furthermore the different o fdrug incorporation techniques have also been shown to effect the drug release rate.The fastest release rate is obtained with water soluble and emulsion ointment bases and the drug release rate from hydrocarbon ointment bases is usually the slowest. Then,the measurement of release rate can be done via a semi permeable membrane.

Apparatus :                                                        Material :

1) Weighing balance                                        1) Emulsifying wax
2) 1 weighing boat                                           2) White soft paraffin
3)  100 ml beaker                                             3) Acetysalicylic acid
4) slab and spatula                                          4) Distilled water
5) 1 set of mortar and pestle
6) 1 bag of dialysis
7)  thread
8) 1 glass rod
9) 1 set of pipette
10)Spectrophotometer UV      

White Soft Paraffin(Petrolleum jelly)

Liquid Paraffin

Emulsifying Wax

Procedure 

1. The ointment is prepared (50 g) via this formula in 70oC-80oC
     1.1 21 g of emulsifying wax
     1.2 25 g of white soft paraffin
     1.3  4 g of liquid paraffin

2.   The 5 g of ointment is weighed and put in weighing boat,label.

3.   The acetylsalicylic (1.5 g) is mixed with ointment that formed via levigation process.Make sure the powder of acetylsalicylic acid is fine and easily dissolve by using mortar and pestle.

4.    The ointment of acetylsalicylic acid is filled into dialysis bag and tied  both end of bag tightly.

5.    The bag is put into the beaker (100 ml) which consist distilled water (50 ml) which already heated ( in 37oC)

6.    The samples in the beaker contain dialysis bag is pipette (3-4 ml) to determine the release rate of acetylsalicylic acid from ointment by using UV spectrometer.The distilled water must be stir by using glass rod before take for the samples

6. With the interval of each 5 minutes, 3-4mL of the distilled water is pipetted out. The release of acetylsalicylic acid from the ointment is determined by using UV-visible spectrometer. Distilled water is stirred before taking the sample.

Time (min)
	0	5	10	15	20	25
UV absorption at 310nm	0	0.035	0.026	0.009	0.007	0.032

Discussion
1. Compare oinment's physical and give a comment.

Emulsifying ointment	Texture			Clarity	Colour
	Spreadibility	Greasiness	Hardness
I	+	+	++++	Unclear	White
II	++	++	+++	Unclear	White
III	+++	+++	++	Unclear	White
IV	++++	++++	+	Unclear	White

The similarity between of all these emulsifying ointments is unclear and white in colour. Based on the table above, emulsifying ointment IV is the most spreadable and greasy. It is followed by emulsifying ointment III, II and I. Emulsifying wax can give stability to the ointment by binding the water and oil or making them miscible and stable. Hence, higher content of emulsifying wax will cause less spreadibility of the ointment, due to much interaction. Meanwhile, emulsifying ointment I is the most hard compared to the others.

Liquid paraffin contributes to the greasiness and hardness of the ointment. High content of liquid paraffin make the ointment become greasier and decrease in hardness.

2.Plot graph UV absorbance versus time.Discuss

UV absorbance showed the different amount of drugs released from the ointment due to the use of different composition which result in varying absorbance at 310 nm in the first 25 minutes.

3.What is the functions of each substances used as excipients in suspenson formulation ?How different Emulsifying Waxand Liquid Paraffin content can affect the physical and stability of suspension formulation and drug flow rate ?

Emulsifying Wax	emulsifiers	Thickeners in formulation
White Soft Paraffin	Hydrocarbon bases	As vehicle from which drug may be absorbed by the skin Emollient for skin
Liquid Paraffin	Hydrocarbon bases	Reduce viscosity
Acetylsalicyclic acid	Active ingredients	Penerate the follicles and facilitates the removal of ead skin from pores
Distilled water	Diluents	Increase bulk volume

Conclusion:

The balance between the amount of emulsifying wax and liquid paraffin in the ointment is important in achieving the desirable traits without compromising the rate of drug release in order to demonstrate the ideal release of drug in systemic circulation.

References

http://books.google.com.my/books?id=J5vE3Z_ZXJcC&pg=PA86&lpg=PA86&dq=tragacanth+in+suspensions&source=bl&ots=TIoQ-FYlzr&sig=PrXeMxvhKQiPpRvsLcW0m2rhkQU&hl=en&sa=X&ei=1iJeU6n3Cs7k8AWNj4DwCQ&redir_esc=y#v=onepage&q=tragacanth%20in%20suspensions&f=false