| الملخص | Abstract
This work has been carried out to develop national drug product contains )5 %( minoxidil as a topical solution, It is used in the treatment of alopecia (hair loss) and alopecia areata minoxidil promotes hair grow by direct dilator effect on the peripheral vessels , and also promoting the epithelium of hair bursa .
Several solutions formulations were prepared using different solutions bases, preservatives and humectants. Selection of best formula relied solelyon physico-chemical testing of sample exposed to thermal stresses.
Stability study was conducted on the product for (6) months at different temperatures to determine the expiration date and the best storage conditions.
From the study we obtained minoxidil topical solution of good clarity.
The expiry date calculated to be not less than (2) years.
Keywords:- Minoxidil , topical solution , Hair loss or Alopecia .
Introduction
Hair loss is a common dermatological problem that affects a large segment of the population both physically and psychologically. Although there are many different causes for hair loss, such as telogen effluvium and alopecia areata, androgenetic alopecia (AGA), i.e., male pattern hair loss and female pattern hair loss, is the most prevalent form in both men and women. Onset of (AGA) can occur anytime at or after puberty, but incidence and severity increases with advancing age in both genders, manifesting in at least (80 %) of caucasian men and (40 %) of women. Because of its considerable psychological impact many patients actively search for new treatments [1] .
Minoxidil is the current standard treatment for hair loss. It was initially used as an oral antihypertensive medication, but because of minoxidil’s side effect of hypertrichosis it was subsequently developed as a topical treatment in (2 %) strength for hair loss. US FDA approval for the treatment of male pattern hair loss (MPHL) was granted to the (2 %) formulation in 1988 and the (5 %) in 1997[1].
Minoxidil solution is used for promoting hair regrowth in patients who are experiencing gradually thinning hair or gradual hair loss on the top of the head . Minoxidil solution is a vasodilator . It is not known how minoxidil solution stimulates scalp hair growth. It is possible that it dilates blood vessels in the scalp, which may improve hair follicle function and stimulate scalp hair growth [2].
Minoxidil is a white or almost white, crystalline powder, slightly soluble in water, soluble in methanol and in propylene glycol [3].
The formula contains minoxidil (5 % w/v) as an active ingredient .
Materials and methods :
Minoxidil topical solution contains ethanol (96 %) , propylene glycol and distilled water as inactive ingredients .
In suitable beaker transfer the following materials, propylene glycol, ethanol 96 % and distilled water, then mix well for (15 min), then add the stated amount of minoxidil , mix well for (30 min),check the (pH) ; it should be between (7 - 8.5) ,complete the volume with distilled water then mix well for (15 min) ,fill in (60 ml) amber glass.
Stability study :
Stability study was conducted on the product for (6) months at different temperatures(R.T,40,50,60) ◦C to determine the expiration date and the best storage conditions.
Results and Discussion
A clear colorless solution was obtained and the physico – chemical properties of it is presented in table (1) .On the other hand , stability studies is presented in tables (2) and (3).
In this study, different formulas of solution were prepared according to the specification of united state Pharmacopoeia 35.
A clear colorless solution of acceptable consistency was produced and the physicochemical also our formula showed excellent stability at different temperatures (R.T, 40, 50, and 60) ◦C.
According to this study, the expiration date has been estimated to be not less than(2) years from the date of manufacturing at room temperature.
Table -1-The physico – chemical changes of minoxidil solution (5% w\v) with time at different temperatures.
Storage time (month) Temp.
◦C)) % of minoxidil pH
(7 – 8.5) appearance
Zero time R.T 103 6.8 Clear colorless solution
1 RT 103 6.88 = = =
40 102.87 6.5 = = =
50 102.49 6.55 = = =
60 101.71 7.0 = = =
2
RT 102.89 6.81 = = =
40 102.74 6.69 = = =
50 102.11 6.89 = = =
60 100.93 6.92 = = =
3
RT 102.78 6.6 = = =
40 102.61 6.8 = = =
50 101.73 6.89 Pale solution
60 100.58 6.87 Yellowish solution
4
RT 102.6 6.78 Clear colorless solution
40 102 6.96 Pale solution
50 101.45 6.93 Yellowish solution
60 99.65 6.98 = = =
5
RT 102.3 6.92 Clear colorless solution
40 101.65 7.14 Pale solution
50 100.82 7.2 Yellowish solution
60 98.54 7.23 = = =
6
RT 102 6.92 Clear colorless solution
40 101.46 7.14 Pale solution
50 100.28 7.2 Yellowish solution
60 97.43 7.23 = = =
Table - 2 -The stability of minoxidil solution (5 %) concentration of minoxidil at zero time =103% of the label amount
(60 ◦C) % Conc.at 50 ◦C) %) Conc.at (40 ◦C) % Conc.at Concentration at( R.T) % Time /day
101.71 102.49 102.87 103 30
100.93 102.11 102.74 102.89 60
100.58 101.73 102.61 102.78 90
99.65 101.45 102 102.6 120
98.54 100.82 101.65 102.3 150
97.43 100.28 101.46 102 180
Regarding the expiry date of the prepared formula we followed the Zero – order rate of reaction that is expected for kinetic of minoxidil solution 5% particularly in the first stage of reduction of concentration.
T90%=0.1C/K
Where:
C=concentration at zero time
K= rate of reaction
T= time /day
Table -3- The (90%) at different temperatures.
T90%Year T90%day Temp.
3.5 2222.5 R.T◦C
2.5 1587.5 40◦C
2 1270 50◦C
1.5 952.5 60◦C
References
1- Omar S. Shamsaldeen, MD; Thamer Al Mubki, MD; Jerry Shapiro, MD, FRCPC, Topical Agents for Hair Growth Promotion, Skin Therapy Letter. 2013;18(4)
2-Online from , http://www.drugs.com/cdi/minoxidil-solution.html , ( Issue Date: June 3, 2015).
3-The British Pharmacopoeia, The Pharmaceutical Press, London, UK, 2013,page (1045)
4-Chemical stability of pharmaceuticals. A. handbook of pharmacists 2nd edition 1986.
5- United state Pharmacopoeia press, 2012, U.S.P 35, U.S.A. | en_US |
