CA2103571C - Method of treating pulmonary inflammation - Google Patents

Abstract

This invention provides a pharmaceutical composition for preventing or reversing pulmonary inflammation in a mammal comprising rapamycin prepared by processes known per se and if desired a pharmaceutically acceptable carrier, diluent or exci-pient; said composition being adapted for administration orally, parenterally, nasally, or intrabronchially. As such, rapamycin is useful in providing the symptomatic relief of diseases in which pulmonary inflammation is a component, such as, asthma, chron-ic obstructive pulmonary disease, emphysema, acute respiratory distress syndrome, bronchitis, and the like.

Description

WO 92/14476 ~ ~ ~ ~ ~ ..~ ~ PCT/US92101398 METHOD OF TREATING
P~.~NA8Y~3.~A7~9N
This invention relates to the preparation of pharmaceutical compositions, in particular compositions containing rapamycin.
Asthma has recently been recognized as being mediated by an inflammatory response in the respiratory tract [DeMonchy, J., Am. Rev. Resp. Dis. ,1~1: 373-(1985)]. Recent findings suggest that human T-lymphocytes play a major role in regulating tht airway inflammation associated with allergic asthma [Frees, A.J., J.
Allergy Clin. Immunol. ,$~: 533-539 (1990)] and. chronic obstructive pulmonary disease [O'Connor, G.T., Am. Rev. Resp. Dis. ~Q: 225-252 (1989)].
In addition to the infiltration of other inflammatory cells into the pulmonary system, human asthmatics and atopics who are dual responders (i.e., show both early and late .phase reactions) show a small but significant infiltration of T-lymphocytes following antigen challenge [Frees, A.J. and Kay, A.B., J. Immunol: ~: 4158-(1988)]. More importantly, these recruited T lymphocytes are almost entirely of the CD4+ (T-helper) type, and them appears to be a direct cornlation between the influx of CD4+ cells, the influx of eosinophils, and the IgE-related allergic response in these individuals [Frees, A.J. and Kay, A.B., J. Immunol. ,1_Q1: 4158-4164 (1988)].
In severe asthmatics, these CD4+ cells appear to be activated [Corrigan, C.J. and Kay, A.B., Am. Rev. Resp. Dis. ~: 970-977 (1990)] by virtue of the increase in IL-2 receptor positive cells. Thus, these cells are capable of producing cytoldnes (such as II~3, IL-5, and grartulocyte macrophage colony stimulating factor) which can directly affect the differentiation, maturation and activation state of the eosinophils and other inflammatory cells.
Rapamycin, a macrocyclic triune antibiotic produced by Streptomyces ~reroscoy~icus [U.S. Patent 3,929,992] has been shown to prevent the formation of humoral (IgE-like) antibodies in response to an albumin allergic challenge [Mantel, R., .
Can. J. Physiol. Pharm. 55: 48 (1977)], inhibit marine T-cell activation [Strauch, M., FASEB 3: 3411 (1989)], and prolong survival time of organ grafts in histoincompatable rodents [Morris, R., Med. Sci. Res. 17: 877 (1989)].
This invention provides a pharmaceutical composition for preventing or reversing pulmonary inflammation in a mammal comprising rapamycin prepared by processes known pgt ~ and if desired a pharmaceutically acceptable carrier, diluent or y y.i ~ _2_ excipient; said composition being adapted for administration orally, parenterally, nasally, or intrabronchially. As such, rapamycin is useful in providing the symptomatic relief of diseases in which pulmonary inflammation is a component such as, asthma, chronic obstructive pulmonary disease, emphysema, acute respiratory distress syndrome, bronchitis, and the like.
The prevention and reversal of pulmonary inflammation by rapamycin was established by the inhibition of pulmonary inflammatory cell influx in an jn vivo standard pharmacological test procedure emulating the inflammatory changes observed clinically in chmnic asthmatics. The procedure used and results obtained are described below.
Male Hartley guinea pigs (400 - 700 g) that have been fasted overnight are sensitized according to a modification of the method of Dunn et al [Am. Rev.
Resp. Dis ],~: 541 (1988)]. Guinea pigs receive ~1 i.m. injection in each hind leg of 0.35 ml (total volume = 0.7 ml) ovalbumin (OA; 50 mg/ml), in isotonic sterile saline.
Following a 3 week sensitization period, each animal is pretreated (-1 h) with pyrilamine (2.5 mg~kg i.p.) to prevent hypoxic collapse and death, and then challenged with an aerosol of 0.290 OA (in distilled deionized water) for 3 min using a DeVilbiss Ultra-Neb 100 nebulizer. Drugs or vehicle (0.59b Tween 80) are administered orally in a volume of 1 m1/500 g body wt. at appropriate times pre- and post- OA
challenge.
Rapamycin was administered orally at -48h, -24h, -lh and +4 hours relative to OA
aerosol. Positive control animals ware challenged with~the OA aerosol, and negative control animals were challenged with an aerosol of distilled water only .
Twenty-four hours later; each animal was humanely sacrificed with an overdose of urethane (60 mg/ml; --10 ml i.p.). The trachea of each animal is isolated and the hlttgs are lavaged ja ~y with three-20 ml washes of isotonic sterile saline.
All samples are kept on ice. This bronchoalveolar lavage fluid from each animal is then centrifuged for 10 min at 400 x g at 5°C. The supernatant is discarded, and each cell pellet is resuspendcd in 3 ml of isotonic sterile saline. The number of inflamtnatory cells present was then determined using a Coulter model ZM particle counter.

2 ~. ~ 3 :~ '~ 1 All values are corrected by subtracting the mean ( x ) value of the negative control group from all other individual samples. Percent inhibition values for individual samples are calculated using these corrected cell counts in the following formula:
96 Inhibition = x ~itive control (corrected) - individual cell count (corrected) X 100 x positive control (corrected) Mean 9'o inhibition is determined for each group and expressed as x inhibition ~ S.E. The EDSps with 95°!o confidence limits are calculated (Litchfield, S.T
and Wilcoxon, F.A., J. Pharmacol. Exp. Ther. Q(1: 99-113 (1949)].
The following table shows the results obtained for guinea pigs treated with various doses of rapamycin (n = 12 animals per treatment group).
INHIBTTION OF PULMONARY INFLAMMATORY CELL INFLUX
Rapamycin Dose (mg,(~g~~.o.) Percent Inhi~ion (mean t std. error) 4.0 88.1 ~ 5.8 1.0 71.5 ~ 13.6 0.3 64.3 ~ 8.2 0.1 , 43.9 ~ 15.0 0.03 ' 13.5 ~ 20.6 The results of this jn Yivo standard pharmacological, test procedure emulating the inflammatory cell changes observed clinically in asthmatics, demonstrates that rapamycin exhibited a dose dependent inhibition of pulmonary inflammatory cell influx with a calculated EDSp (9596 C.L.) of 0.2 (0.08 - 0.60) mg/kg in response to an antigenic challenge, and is therefore useful in preventing or reversing pulmonary inflammation and in treating disease states in which pulmonary inflammation is a component such as, asthma, chmnic obstructive pulmonary disease, emphysema, acute respiratory distress syndrome, bronchitis, and the like.
When rapamycin is employed in the treatment of pulmonary inflammation, it can be formulated into oral dosage forms such as tablets, capsules and the like.
Rapamycin can be administered alone or by combining it with conventional carriers, such as magnesium carbonate,~magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose, low melting wax, cocoa butter and the like. Diluents, flavoring agents, solubilizers, lubricants, suspending agents, binders, tablet-disintegrating agents and the like may be employed. Rapamycin may be encapsulated with or without other carriers. In all cases, the proportion of active ingredients in said compositions both solid and liquid will be at least to impart the desired activity thereto on oral adminf stration. dtapamycin may also be injected parenterally, in which case it is used in the form of a sterile solution containing other solutes, for example, enough saline or glucose to make the solution isotonic. For administration by intranasal or intrabronchial inhalation or insufflation, rapamycin may be formulated into an aqueous or partially aqueous solution, which can then be utilized in the form of an aerosol.
The dosage requirements vary with the particular compositions employed, the route of administration, the severity of the symptoms presented and the particular subject being treated. Based on the results obtained in the standard pharmacological test procedure, projected oral daily dosages of active compound would be 0.01 -mg/kg, preferably between 0.1 - 10 mg/kg, and more preferably between 0.3 - 4 mg~kg. Treatment will generally be initiated with small dosages less than the optimum dose of the compound. Thereafter the dosage is increased until the optimum effect under the circumstances is reached; precise dosages for oral, parenteral, nasal, or intrabr~nchial administration will be determined by the administering physician based on experience with the individual subject treated. In general, rapamycin is most desirably administered at a concentration that will generally afford effective results without causing any harmful or deleterious side effects, and can be administers either as a single unit dose, or if desired, the dosage may be divided into convenient subunits administered at suitable times throughout the day.

Claims (14)

CLAIMS:

1. A pharmaceutical composition for preventing or reversing pulmonary inflammation in a mammal which comprises rapamycin and a pharmaceutically acceptable carrier, diluent or excipient, said composition being adapted for administration orally, parenterally, intranasally, or intrabronchically.

2. A pharmaceutical composition according to Claim 1 for providing symptomatic relief of asthma, chronic obstructive pulmonary disease, emphysema, acute respiratory distress syndrome, or acute bronchitis in a mammal.

3. A pharmaceutical composition according to Claim 1 or Claim 2 in a unit dose form.

4. A pharmaceutical composition according to Claim 3 in which the unit dose is 0.01 to 10 mg/kg based on the weight of the mammal to be treated.

5. A pharmaceutical composition according to Claim 3 in which the unit dose is 0.1 to 10 mg/kg based on the weight of the mammal to be treated.

6. A pharmaceutical composition according to Claim 3 in which the unit dose is 0.3 to 4 mg/kg based on the weight of the mammal to be treated.

7. The use of an effective amount of rapamycin in a form suitable for oral, parenteral, intranasal, or intrabronchial administration for preventing or reversing pulmonary inflammation in a mammal in need thereof.

8. The use according to Claim 7, wherein the rapamycin is in a daily dose of 0.01 to 10 mg/kg.

9. The use according to Claim 7, wherein the rapamycin is in a daily dose of 0.01 to 10 mg/kg.

10. The use according to Claim 7, wherein the rapamycin is in a daily dose of 0.3 to 4 mg/kg.

11. The use of an effective amount of rapamycin in a form suitable for oral, parenteral, intranasal, or intrabronchial administration for providing symptomatic relief of asthma, chronic obstructive pulmonary disease, emphysema, acute respiratory distress syndrome, and acute bronchitis in a mammal in need thereof.

12. The use according to Claim 11, wherein the rapamycin is in a daily dose of 0.01 to 10 mg/kg.

13. The use according to Claim 11, wherein the rapamycin is in a daily dose of 0.1 to 10 mg/kg.

14. The use according to Claim 11, wherein the rapamycin is in a daily dose of 0.3 to 4 mg/kg.