Stability of Aqueous solutions of naltrexone

[Guest guest]

Dear low dosers,

I have read several posts that describe the preparation of water-based solutions

of

naltrexone. I agree with cyber_guy that the easiest low-dose preparation method

is to

make a water-based solution, as he describes in:

http://goodshape.net/HomemadeLDN.html

The only comment I have regards the stability of aqueous solutions of

naltrexone.

Unfortunately, aqueous solutions of naltrexone are not stable indefinitely.

Naltrexone is also light sensitive.

That is why naltrexone in pill form should come in an opaque container with a

desiccant to

remove moisture.

I have included the abstract of a research article discussing the stability of

aqueous

solutions of naltrexone.

The take home message is as follows:

********************************************************************************\

***********

Naltrexone 1 mg/mL oral liquids prepared from tablets or powder are stable when

stored

in the dark for 60 days at 4 degrees C (the typical refrigerator temperature)

and for 30

days at 25 degrees C (room temperature).

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***********

So, rest assured that your aqueous solution of naltrexone is stable as long as

it is stored

IN THE DARK, for the lengths of times at the appropriate temperatures described

above.

Lord knows we don't want to be losing any benefits of low-dose naltrexone

because our

water-based solution was decomposing.

Best regards,

Dean

--

Dr. Dean Cuebas, Associate Prof of Chemistry

deancuebas@..., Ph 417-836-8567 FAX 417-836-5507

Dept. of Chemistry, Missouri State University

Springfield, Missouri 65897

?

Reference:

Ann Pharmacother. 1997 Nov;31(11):1291-5

Formulation and stability of naltrexone oral liquid for rapid withdrawal

from

methadone.

Fawcett JP, NC, Woods DJ.

School of Pharmacy, University of Otago, Dunedin, New Zealand.

OBJECTIVE: To assess the stability of naltrexone oral liquid prepared from

tablets and

powder, and to evaluate its use in precipitating rapid withdrawal from

methadone. DESIGN:

Naltrexone 1 mg/mL oral liquids were prepared from tablets and powder and stored

in the

dark at 4, 25, and 70 degrees C. Similar formulations containing 5 mg/mL were

stored at

70 degrees C. The 1-mg/mL formulation prepared from tablets was clinically

evaluated in

inducing rapid withdrawal in two drug-dependent individuals receiving methadone

maintenance treatment using a naltrexone dose titration protocol. SETTING: A

university

pharmacy school and affiliated urban teaching hospital. MAIN OUTCOME MEASURES:

Samples removed at six time points were analyzed for naltrexone concentration to

assess

decomposition over 90 days. An opioid withdrawal symptom checklist was used to

assess

the severity of the withdrawal symptoms prior to, and 30 minutes after, each

dose of

naltrexone. RESULTS: Decomposition of naltrexone in all formulations stored at 4

and 25

degrees C was not significant over 90 days. Both patients tolerated naltrexone 1

mg/mL

oral liquid, but found it bitter and gritty. Withdrawal symptoms were

experienced

immediately after the first dose, but were resolving by the end of day 3 of

naltrexone

treatment, at which stage both patients were able to tolerate a 50-mg tablet of

naltrexone

as maintenance. CONCLUSIONS: Naltrexone 1 mg/mL oral liquids prepared from

tablets or

powder are stable when stored in the dark for 60 days at 4 degrees C and for 30

days at

25 degrees C. The formulation prepared from tablets provides flexible dosing in

patients

undergoing rapid withdrawal from methadone.